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Treatment considerations in salivary gland surgery
TREATMENT CONSIDERATIONS IN SALIVARY GLAND SURGERY MICHAEL EUGENE
FRIEDMAN, N. M Y E R S ,
We asked the three experts n a m e d in the byline of this article to provide treatment recommendations in five cases of parotid tumor. I believe their varying perspectives provide interesting insight into the "state of the art" in approaches to parotid surgery. Michael Friedman, MD, Editor CASE 1 A 49-year-old man presents with a slowly enlarging left parotid tumor. The seventh nerve is intact. Preoperative CT shows a mass in the superficial lobe extending to the deep lobe and involving the skin. There is no cervical adenopathy. No fine-needle aspiration is performed. The patient undergoes total parotidectomy without neck dissection. The seventh nerve is not identified during surgery. Pathological examination shows poorly differentiated mucoepidermoid carcinoma. After surgery, the patient experiences complete ipsilateral facial paralysis. A repeated CT scan performed 1 month after surgery
From the Department of Otolaryngology and Bronchoesophagology, Rush Medical College, Rush-Presbyterian-St. Luke's Medical Center, Chicago, IL; the Division of Head and Neck Surgery, UCLA School of Medicine, LA; the Department of Otolaryngology, University of Pittsburgh School of Medicine Eye and Ear Institute; and the Head and Neck Service, Memorial Sloan-Kettering Cancer Center, NY. Address reprint requests to Michael Friedman, MD, Department of Otolaryngology and Bronchoesophagology, Rush-Presbyterian-St. Luke's Medical Center, 1653 W Congress Pkwy, Chicago, IL 60612. Copyright © 1996 by W.B. Saunders Company 1043-1810/96/0704-0014505.00/0
MD, ELLIOT MD, RONALD
ABEMAYOR, MD, H. SPIRO, MD
shows residual tumor extending to the surface (Fig 1).
Questions Should the patient undergo surgery, radiation, or both? If surgery, should the procedure include skin resection? How should the skin be resurfaced? Should nerve resection, with or without a nerve graft, be done? If radiation, should neutron radiation be used? Dr Abemayor: This patient poses a difficult dilemma. The postoperative facial paralysis is likely due to iatrogenic injury. In addition, this patient has been inadequately treated with gross t u m o r still present. The issues with this patient are the following: (1) what is the best way to achieve optimal locoregional control of disease?; and (2) h o w can we rehabilitate this patient at the same time? The best h o p e for tumor control or cure is removal of gross disease followed by radiation treatment. This patient needs a radical parotidectomy, lateral temporal bone resection, and a right modified neck dissection. His facial paralysis is of 1 month's duration, so electrical stimulation of the peripheral branches is not possible. Therefore, I w o u l d begin with an anatomic dissection of the peripheral branches of the facial nerve tagging the eye, buccal, and marginal branches. After this, I w o u l d perform a mastoidectomy and identify the facial nerve in its descending portion and trace it to its exit at the stylomastoid foramen. Frozen-section control of the facial nerve for the presence of t u m o r is performed. Following negative margins, I w o u l d
PhD,
p e r f o r m a lateral temporal bone resection and radical p a r o t i d e c t o m y encompassing the superficial lobe, deep lobe, and the facial n e r v e itself. Interpositional cable grafts are then inserted between the remaining trunk of the facial nerve and the peripheral branches previously tagged. The best source for the cable grafts are the sensory nerves f o u n d at the inferior portion of the neck or, a second choice, the sural nerve. A gold weight w o u l d be placed to protect the eye since, until, and if, function returns, the eye is at risk for injury. A modified neck dissection is p e r f o r m e d both for treatment and staging. I would also remove the skin overlying the tumor and excise it in continuity with the parotidectomy. Closure of this defect is best accomplished with a pectoral-cervical-facial rotation flap. I would r e c o m m e n d postoperative radiation because this is a poorly differentiated lesion with a violated t u m o r bed. The locoregional control rate w o u l d be increased with external b e a m r a d i o t h e r a p y using cobalt-60 with an electric b e a m boost to about 60 Gy. Because this is a p o o r l y differentiated lesion, any a d d e d adv a n t a g e of using n e u t r o n b e a m therapy is doubtful. REFERENCE 1. TranL, Sadeghi A, Hanson DG, et al: Major salivary gland tumors: Treatment results and prognostic factors. Laryngoscope 96: 1139-1144, 1986 Dr Myers: There are several flaws in the initial m a n a g e m e n t of this patient. The most outstanding is that there was no diagnosis m a d e before surgery. If a t u m o r involves the deep
OPERATIVE TECHNIQUES IN OTOLARYNGOLOGY--HEAD AND NECK SURGERY, VOL 7, NO 4 (DEC), 1996: PP 377-383
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FIGURE 1.
lobe and skin, one would have to suspect the presence of a malignant tumor. The dissection was clearly inadequate because 1 month after surgery, residual tumor is noted. An error in judgment/technique resulted in injury to the facial nerve. Whether this nerve has been resected or been injured in some other procedure is unclear. In my opinion, this patient should undergo radical surgery and postoperative adjunctive radiation therapy. Several issues should be addressed.
• Adequacy of resection. This surgery must include the residual tumor and the overlying skin, the masseter muscle, the periosteum of the mandible, the anterior cartilaginous external auditory meatus, the anterior aspect of the superior portion of the sternocleidomastoid muscle, and the posterior belly of the digastric muscle. • A modified radical neck dissection type 1 should be performed. The incidence of cervical lymph node metastasis in patients with high-grade mucoepidermoid carcinoma is higher than in any other malignant tumor of salivary gland origin. • Several types of reconstruction must be performed. The choices in order of my own preference would be the following: 378
Cervical-pectoral rotation flap (this would give the best color match and restore some bulk). Rectus abdominis free flap with split-thickness skin graft would provide bulk for contouring, but would be a poor color match. Facial nerve. The facial nerve should be resected with the main specimen. A mastoidectomy should be performed in order to identify the descending portion of the facial nerve. Frozen-section should be performed on the proximal resection margin of the nerve. Once adequate tumor clearance of the nerve has been achieved, a sural nerve graft or a graft taken from C4 (cervical plexus) should be used as a free graft. An effort should be made to identify the peripheral branches of the facial nerve, although 1 month after surgery, this may be very difficult to do because the nerves may not function even with electrical stimulation. If the branches can be identified, then the nerve graft should be anastomosed with the peripheral branches. If no branches can
be identified with certainty, then the nerve graft should be placed into the frontalis muscle of the orbicularis oculi muscle and the orbicularis oris muscle. A fascia lata sling would provide for a straight commissure in the event that nerve grafting was not performed, but is a poor second choice in my opinion. A gold weight should be placed in the upper eyelid to provide adequate eye closure whether or not the nerve can be reconstructed. The patient should receive postoperative adjunctive radiation therapy in order to neutralize the effect of cervical lymph node metastasis, facial nerve involvement and soft tissue extension, all of which are "aggressive" pathological findings. Neutron radiation has been shown to be useful in salivary gland tumors; however, there are only a few centers in this country in which this therapy is available and, although this treatment has been found to be efficacious, it may not be practical. Dr Spiro: In the absence of specific information, I assume that this patient had undergone a total parotidectomy with unintentional facial nerve DIFFICULT DECISIONS
injury or transection. Experienced surgeons m a y undertake a subtotal p a r o t i d e c t o m y in a clinically obvious setting without a preoperative needle aspiration biopsy (FNAB), but a histological diagnosis is essential (either preoperative FNAB or intraoperative frozen section) w h e n the findings suggest that the patient m a y require a more extensive procedure with greater risk to the facial nerve. The highly aggressive course in this case (ie, obvious recurrence within 1 month) is unusual even for poorly differentiated mucoepidermoid carcinoma. It indicates that gross residual t u m o r remained after inadequate initial surgery, a most u n h a p p y problem which is likely to defeat all subsequent efforts at salvage. If the recurrence is d e e m e d resectable, this patient's best chance for salvage w o u l d seem to be additional surgery followed b y postoperative radiation therapy (RT). The decision w h e t h e r to sacrifice overlying skin must be based on clinical evidence of dermal invasion. My preference for resurfacing is a large cervical rotat i o n / a d v a n c e m e n t flap, the incision for which is carried as far inferiorly on the anterior chest wall as necessary to allow the flap to reach the skin defect. Isolation of proximal and distal facial nerve branches 1 m o n t h after a "total" parotidectomy is likely to be a frustrating exercise with very limited prospect for good functional restoration by nerve grafting. I think it w o u l d be more reasonable to ignore the facial nerve during the second procedure, and insert a gold weight implant at the same sitting. Additional procedures for dynamic s u p p o r t can be considered later if locoregional control is achieved. Recognizing that resectability can be hard to assess, it w o u l d be wise to have the b r a c h y t h e r a p y team standing by. If gross t u m o r still remains after the re-resection, we have f o u n d that an implant placed in the area of concern, in conjunction with b e a m RT, can enhance t u m o r control. W h e n it is not clear that residual or recurrent salivary gland carcinoma can be completely resected, consideration should be given to neutron irradiation. Published data suggest that local control m a y be better than that which can be achieved by incom-
FRIEDMAN ET AL
plete surgery and p h o t o n irradiation.
CASE 2 A 58-year-old woman presents with a parotid tumor. Twenty years ago the mass was biopsied through the skin, and subtotal tumor resection was performed. The pathological report at that time was consistent with pleomorphic adenoma. The patient now presents with a 1-year history of multicentric recurrences. The tumor is fixed to the skin at several sites. A level II neck node is palpable. A fine-needle aspiration specimen is positive for pleomorphic adenoma. Questions What procedure is appropriate? Skin resection? If so, how should the skin be resurfaced? Should the deep lobe be addressed? Should postoperative radiation be used? Dr Abemayor: This patient suffers from a recurrent pleomorphic adenoma due to tumor spillage and inadequate excision. Such tumors are best considered as low-grade potentially aggressive neoplasms; even with further excisions, the patient is at risk for local recurrences with subsequent danger to facial function. I would begin by reviewing the prior operative note if possible. Was the t u m o r r e m o v e d b y enucleation or lateral lobectomy? This is important to k n o w because, in turn, it can tell us if the main trunk of the facial nerve was dissected out or not. In any event, extirpation of this tumor requires removal of all remaining parotid tissue and surrounding skin which is seeded with t u m o r cells. Under loupe magnification and using facial nerve monitoring, I w o u l d see if the main trunk of the nerve can be easily identified proximally. If not, I w o u l d find the peripheral branches (eye, buccal, marginal mandibular) and trace them back to the main trunk, removing any remaining superficial parotid tissue and residual tumor. Once the nerve is identified, the deep lobe tissue can also be removed. The level II n o d e and any other palpable nodes w o u l d be re-
m o v e d as a functional neck dissection. The involved cheek skin w o u l d be excised with resurfacing of the defect using a chest-cervical-cheek rotation flap. Due to this patient's relative youth, I w o u l d not use adjunctive radiation therapy for lesions that are still surgically resectable. For multiple recurrent lesions, I believe a radical parotidectomy with either pedicle or free flap muscle reconstruction is warranted.
REFERENCE 1. Conley JJ (ed): Problems with operation of the parotid gland and facial nerve. Otolaryngol Head Neck Surg 99:480-488, 1988 Dr Myers: The initial flaw in the m a n a g e m e n t of this patient was inadequate resection of the tumor. Patients w h o have been inadequately resected for pleomorphic a d e n o m a are at risk for recurrence of the pleomorphic adenoma or for development of carcinoma expleomorphic adenoma. The time sequence of 20 years after the initial surgery is possible in both instances. The fixation of the t u m o r to the skin and a palpable level II l y m p h node make one more suspicious about carcinoma exp l e o m o r p h i c a d e n o m a . The fineneedle aspiration specimen positive for pleomorphic a d e n o m a is not a guarantee that carcinoma ex-pleomorphic a d e n o m a is not present. I w o u l d r e c o m m e n d open biopsy of these nodules in order to establish a diagnosis. In m y experience, recurrent pleomorphic a d e n o m a can usually be adequately treated by total parotidectomy with facial nerve dissection. There is no mention about the condition of this patient's facial nerve, so for the sake of discussion, I assume that it is normal. If this is purely pleomorphic adenoma, I w o u l d excise the skin overlying several sites where the t u m o r is fixed to the skin and close these primarily. Removal of the t u m o r mass should provide e n o u g h additional skin in a 58-year-old w o m a n to close these areas primarily. During the time that the parotid is exposed, the level IF l y m p h node should be removed. This area is exposed during most parotid surgery, and by retracting the posterior belly
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of the digastric superiorly, the mass can be exposed and removed. If the initial biopsy revealed tumor in a lymph node, then one must conclude that this is malignant even though open biopsy of the primary tumor may have been diagnosed as pleomorphic adenoma on frozen section. If the tumor is adherent to the branches of the facial nerve, the individual branches should be resected and cable grafts should be applied. By extensive dissection posteriorly, the great auricular nerve, if it can be found, may be used. If not, then the fourth cervical nerve can be used, which is very helpful because it has multiple branches. If upon biopsy of the tumor mass, it is proven to be a carcinoma expleomorphic adenoma, then the patient's best interest would be best served by a complete resection of the entire parotid gland, the masseter muscle, the periosteum of the mandible, the facial nerve, and the overlying skin. If the facial nerve must be sacrificed, then replacement with sural nerve or cervical plexus nerve grafting may be performed. In the event that the mass is malignant, then a modified radical neck dissection should be performed. I don't believe in the use of radiation therapy for the treatment of benign tumors, although there is lit-
erature, particularly from the United Kingdom, on the routine treatment of pleomorphic adenoma, particularly recurrent, by radiation therapy. If this is a malignant tumor, then postoperative radiation therapy should be used as has been shown over many years that locoregional recurrence is improved even though the cure rate is not necessarily improved. Dr Spiro: The obvious explanation for the multifocal recurrence in this patient would seem to be seeding from the inappropriate "subtotal tumor resection" performed 20 years previously. The presence of a palpable level II lymph node, however, is troublesome despite the FNAB report of pleomorphic adenoma. It would be wise to aspirate the neck node. If this yielded tissue similar to that obtained from one of the parotid masses, the true diagnosis may actually prove to be malignant mixed tumor. Assuming the benign diagnosis is correct, an adequate subtotal parotidectomy with facial nerve sparing should be possible when the previous procedure has not exposed the nerve. There is no need for total parotidectomy unless the deep lobe is obviously involved. The patient needs to be especially well prepared
for the possibility of postoperative facial nerve dysfunction. In addition to the likelihood of direct nerve trauma during what often proves to be a more tedious dissection because of scarring, sacrifice of a nerve branch with cable grafting may occasionally be required when nerve and tumor are so intimately related that separation of the two will leave residual tumor. Dermal involvement from multifocal tumor recurrence poses a problem that is best resolved by excision of the overlying skin. Depending on the circumstance, resurfacing can be accomplished by split grafting, a cervical/facial rotation advancement flap (as mentioned previously) or free, revascularized tissue. Even with confidence in a benign diagnosis, it would be wise to excise the enlarged level II lymph node. If there is any question of malignant evolution of a benign pleomorphic adenoma, a limited lymphadenectomy (levels I, II, III) should be added to the parotidectomy. Recent experience suggests that adjunctive beam radiation therapy may offer enhanced locoregional control in patients with recurrent pleomorphic adenoma. Indications are far from clear, but the best results are obtained when it is given after a good debulking procedure that re-
FIGURE 2.
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DIFFICULT DECISIONS
FIGURE 3. moves all gross tumor. I n o w tend to use the RT sooner, rather than later. Even if a good cleanout is accomplished, this particular patient remains at high risk for another recurrence, at w h i c h time additional, nerve-sparing surgery is quite unlikely.
CASE 3 A 48-year-old woman has undergone right-sided parotidectomy twice for mixed tumor. She has a positive neck node, and results of fine-needle aspiration are positive for pleomorphic adenoma. CT scans are shown in Figs 2 and 3. Questions What procedure is appropriate? Should an external surgical approach be used, with or without cutting the mandible? A transoral approach? Or a combined external and transoral approach? Should postoperative radiation be administered? Dr A b e m a y o r : This patient has a r e c u r r e n t p a r a p h a r y n g e a l tumor. Most can be r e m o v e d through the neck; however, I also prepare the FRIEDMAN ET AL
patient for a possible m a n d i b u lotomy. This t u m o r is best approached through a transcervicaltransparotid route. In this fashion, the great vessels and the lower branches of the facial nerve are identified and protected, i prefer the approach popularized by Stell et al 1 and clearly described by Olsen. 2 In essence, this approach identifies at least the lower branches of the facial n e r v e out to the s u b m a n d i b u l a r gland. Once the sternocleidomastoid muscle is retracted laterally and cranial nerves X-XII are identified, the carotid artery and jugular vein are laterally retracted. Routing sacrifice of the external carotid artery is not always n e e d e d but can be done for a d d e d exposure. The angle of the mandible is retracted anteriorly and, if further exposure is needed, the submandibular gland is removed. With retraction of the mandible, the stylomandibular ligament is visualized and divided, resulting in a larger o p e n i n g into the p a r a p h a r y n g e a l space. For even more medial and superior exposure, m a n d i b u l o t o m y at the angle is added. In such cases, I first put the patient in maxillomandibular fixation using cortical bone screws at the nasal p y r i f o r m aperture and lower mandible. Before the
mandibulotomy, I contour a 4-hole compression plate for later use in mandibular fixation. Under direct visualization and with digital manipulation, the mass is removed. All attempts should be m a d e to preserve the integrity of the t u m o r ' s capsule. Intraoral excision is contraindicated because of possible infection, t u m o r seeding, or d a m a g e to vital vascular structures. T h r o u g h the transcervical approach, a s u p r a h y o i d neck dissection is possible to remove any l y m p h nodes or tumor-beading tissue. Because of the patient's age, i w o u l d reserve radiation for recurrent lesions not amenable to further surgical excision.
REFERENCES 1. Stell PH, Mansfield AO, Stoney PJ: Surgical approaches to tumors of the parapharyngeal space. Am J Oto]aryngol 6:92-97, 1988 2. Olsen KD: Tumors and surgery of the parapharyngeal space. LaryngoscopeSuppl 63:104, 1994 Dr Myers: This case presents a patient with a p a r a p h a r y n g e a l space extension of a deep lobe parotid tumor. These tumors arising from the deep lobe are, in m y experience, pleomorphic adenoma, carcinoma ex381
pleomorphic adenoma, or malignant mixed tumor. Although the fineneedle aspiration biopsy report is positive for pleomorphic adenoma, the possibility of carcinoma ex-pleomorphic adenoma or malignant mixed tumor is not necessarily established without adequate histopathology. The diagnosis is verified by the scan shown in Fig 3. One would have to be somewhat circumspect about the possibility of malignancy because the patient is said to have a "positive neck node." Because of the mention of this lymph node, this is a rather enigmatic situation. If the patient was known with certainty to have a pleomorphic adenoma, it should be removed through a parotid-submandibular approach in order to provide adequate exposure. The submandibular gland should be mobilized by ligating and transecting the facial artery posteriorly, and pedicaling the submandibular gland on the lingual nerve and the Wharton's duct. A total parotidectomy should be performed, carefully dissecting and preserving the facial nerve. This will allow adequate access to the deep lobe tumor and, by approaching it laterally from the exposure gained by a parotidectomy as well as the submandibular approach to the parapharyngeal space, the tumor can be removed, preserving the facial nerve. In my experience, a mandibulotomy approach is not necessary. A transoral approach, although it has been reported by Goodwin et al some years ago, 1 is potentially dangerous to the facial nerve in the resection of a deep lobe tumor, especially in a previously operated case. If this proves to be a malignant tumor, then postoperative radiation should be most certainly administered. REFERENCE 1. Goodwin WJ, Chandler JR: Transoral excision of lateral parapharyngeal space tumors presenting intraorall. Laryngoscope 98:266-269,1988 Dr Spiro: This patient's MRI shows a typical intraoral presentation of a deep lobe or retromandibular parotid tumor, which I would not expect to be palpable in the neck. If the
382
"positive neck node" implies another, separate cervical mass, then I would have the same concerns about the possibility of malignant transformation that I expressed previously. I will always attempt transcervical resection of retromandibular parotid tumors with the patient prepared for the possibility of a paramedian mandibulotomy. The transcervical approach should start with exposure and identification of the facial nerve trunk and its ramus marginalis branch in order to avoid injury to these structures. If this access proves inadequate, which is seldom the case, the mandible is divided between the ipsilateral cuspid and lateral incisor. The paralingual incision is then carried up to the soft palate, which usually provides good external and transoral exposure. I believe that any attempt at direct transoral removal is ill-advised and inappropriate. Regardless of the approach, resection of deep lobe tumors entails a certain amount of blunt dissection. Given that margins are often minimal, I believe that postoperative irradiation is usually indicated in any patient whose lesion proves to be malignant. CASE 4 A 38-year-old HIV-positive man presents with a right-sided parotid mass with cervical nodes. Questions What imaging studies, if any, should be done? Should fineneedle aspiration be done? At surgery, is biopsy of the node alone required? Should a parotidectomy be done? Dr Abemayor: HIV-positive patients can develop benign lymphoepithelial cysts of the parotid that in reality are cystic, incompletely encapsulated lymph nodes. These patients are also prone to developing lymphomas that are amenable to medical therapy. Therefore, a diagnosis of these lesions is needed. I would begin with a contrast CT. Are other lesions visible in the contralateral parotid and neck? If so, this would strongly suggest a working diagnosis of "benign" HIV cysts.
I would also perform a fine-needle aspiration of the neck mass. In the hands of an experienced cytopathologist, a cell button can be prepared and lymphoma ruled in or out. If further definition of tissue type is needed, I could excise the neck mass. Cystic parotid lesions in HIVpositive patients act as inflammatory masses, making identification and preservation of the facial nerve difficult. Therefore, I would avoid a parotidectomy and concentrate on the cervical lymph nodes. REFERENCE 1. Finter MD, Schinella RA, Rothskin S, Persky M: Cysticparotid lesions in patients at risk for the Acquired Immunodeficiency Syndrome. Arch Otolaryngol Head Neck Surg 114:1290-1294,1988 Dr Myers: In my opinion, this patient has a lymphoepithelial lesion that is highly correlated with HIVpositivity. MRI scanning is usually helpful in such a case. Fine-needle aspiration biopsy should be performed. These lymphoepithelial cysts can be aspirated. Sometimes the cysts are painful and the patient is relieved of pain by repeat aspiration. Special precautions should be taken by the caregiver in order to avoid auto-inoculation of the HIV. It is not necessary or recommended that surgery be performed, and parotidectomy is contraindicated unless there is strong suspicion of associated malignancy. There is also a higher than expected incidence of lymphoma in HIV-infected patients and, if clinical behavior or adjunctive studies indicate the possibility of lymphoma, then open biopsy to establish this diagnosis should be performed. Dr Spiro- The association of parotid masses with seropositivity to HIV is now well recognized. Usually these are cystic and part of a pattern of generalized lymphadenopathy, which is often bilateral. FNAB of the parotid mass is indicated, and will probably yield turbid, amber, or milky fluid and cellular architecture similar to that observed in benign lymphoepithelial lesions. Limited surgery to remove the cystic mass may be appropriate in this setting, particularly when pain or discomfort are present. Other possibilities inDIFFICULT DECISIONS
clude a primary Kaposi's sarcoma arising in the parotid gland, or possibly even an unrelated primary carcinoma, either of which should be suggested by the FNAB findings. Parotidectomy is best avoided when the process is benign and HIV-related, unless the patient has multiple, symptomatic masses. In the presence of other, potentially lethal pathology, the extent of the indicated parotidectomy will depend on the stage and histology of the lesion, and neck dissection may also be required.
CASE 5 A 64-year-old man presents with a tumor at the tail of the parotid. Surgery discloses a 2 × 2 cm, relatively soft mass caudal to the marginal mandibular branch of the facial nerve (Fig 4).
Questions Are any imaging studies needed? Should a complete dissection be done along the distal aspects of the upper branches of the facial nerve (because this part of the gland is more than 4 cm away from the tumor)? Or will it be adequate to dissect the upper branches of the nerve just far enough to transect the gland and still provide wide margins away from the tumor?
Dr Abemayor: A contrast CT or MRI with gadolinium is helpful to inform the patient and prepare the patient and surgeon for a possible deep lobe or dumbbell parotid tumor. This is especially important, because the tumor is in the parotid tail. I would approach this tumor by finding the main trunk of the facial nerve inferior and medial to the tympanomastoid structure and then identifying the pes ansefinus distally. Given the tumor's inferior location, it is adequate to dissect the tumor off the inferior branches of the nerve and dissect the upper branches of the nerve just far enough to transect the gland. I believe this would provide adequate margins with minimal potential morbidity.
lower division of the facial nerve. I make an effort to ligate the Stensen's duct in order to prevent postoperative salivary fistula. The tumor can then be removed. Protecting the upper division without necessarily dissecting it, provides an efficient and effective way of dealing with these tumors. Dr Spiro: The information provided strongly suggests that this patient has a Warthin's tumor in the tail of his parotid gland. At issue is the question of preoperative evaluation and the type of operation to be performed. Although the clinical impression could be easily verified by FNAB or a technetium scan, I do not see a compelling indication for either procedure unless the surgeon has decided to perform a limited local excision, rather than a parotidectomy. I believe that a case can be made for less than a subtotal parotid resection with facial nerve dissection in carefully selected patients with small, benign tumors in the tail of the gland. An important caveat for those who would perform limited excision without nerve exposure is that the ramus marginalis branch is always closer than one might think. Although this can be minimized by nerve exposure and partial removal of the inferior portion of the gland lateral to it, there may be increased risk of salivary drainage following partial excision.
Dr Myers: This, in my experience, is a very common problem and this patient probably has a papillary cyst adenoma lymphomentosum (Warthin's tumor). Warthin's tumors commonly occur in the tail of the parotid. In my opinion, tumors in the tail of the parotid, whether they are Warthin's or other benign tumors, can be removed without dissecting the entire facial nerve or removing the entire superficial lobe of the parotid gland. I always identify the main trunk of the facial nerve as it exits the stylomastoid foramen, carry the dissection anteriorly until the bifurcation of the nerve is noted, and then dissection is continued along in order to expose the branches of the
Parot Glandid
TemporalBranch ~ ~~" ~ J ' ~~
Facial~ ~
terMuscl oc,e,i: e /j~ Tumor~-
ZygomaticBranch
~L~.~~
BuccalBranch
~
MandibularBranch
~
~'~~
~
Mandible
)~CervicalBranch ,-/
FIGURE 4.
FRIEDMAN ET AL
383
FRIEDMAN, N. M Y E R S ,
We asked the three experts n a m e d in the byline of this article to provide treatment recommendations in five cases of parotid tumor. I believe their varying perspectives provide interesting insight into the "state of the art" in approaches to parotid surgery. Michael Friedman, MD, Editor CASE 1 A 49-year-old man presents with a slowly enlarging left parotid tumor. The seventh nerve is intact. Preoperative CT shows a mass in the superficial lobe extending to the deep lobe and involving the skin. There is no cervical adenopathy. No fine-needle aspiration is performed. The patient undergoes total parotidectomy without neck dissection. The seventh nerve is not identified during surgery. Pathological examination shows poorly differentiated mucoepidermoid carcinoma. After surgery, the patient experiences complete ipsilateral facial paralysis. A repeated CT scan performed 1 month after surgery
From the Department of Otolaryngology and Bronchoesophagology, Rush Medical College, Rush-Presbyterian-St. Luke's Medical Center, Chicago, IL; the Division of Head and Neck Surgery, UCLA School of Medicine, LA; the Department of Otolaryngology, University of Pittsburgh School of Medicine Eye and Ear Institute; and the Head and Neck Service, Memorial Sloan-Kettering Cancer Center, NY. Address reprint requests to Michael Friedman, MD, Department of Otolaryngology and Bronchoesophagology, Rush-Presbyterian-St. Luke's Medical Center, 1653 W Congress Pkwy, Chicago, IL 60612. Copyright © 1996 by W.B. Saunders Company 1043-1810/96/0704-0014505.00/0
MD, ELLIOT MD, RONALD
ABEMAYOR, MD, H. SPIRO, MD
shows residual tumor extending to the surface (Fig 1).
Questions Should the patient undergo surgery, radiation, or both? If surgery, should the procedure include skin resection? How should the skin be resurfaced? Should nerve resection, with or without a nerve graft, be done? If radiation, should neutron radiation be used? Dr Abemayor: This patient poses a difficult dilemma. The postoperative facial paralysis is likely due to iatrogenic injury. In addition, this patient has been inadequately treated with gross t u m o r still present. The issues with this patient are the following: (1) what is the best way to achieve optimal locoregional control of disease?; and (2) h o w can we rehabilitate this patient at the same time? The best h o p e for tumor control or cure is removal of gross disease followed by radiation treatment. This patient needs a radical parotidectomy, lateral temporal bone resection, and a right modified neck dissection. His facial paralysis is of 1 month's duration, so electrical stimulation of the peripheral branches is not possible. Therefore, I w o u l d begin with an anatomic dissection of the peripheral branches of the facial nerve tagging the eye, buccal, and marginal branches. After this, I w o u l d perform a mastoidectomy and identify the facial nerve in its descending portion and trace it to its exit at the stylomastoid foramen. Frozen-section control of the facial nerve for the presence of t u m o r is performed. Following negative margins, I w o u l d
PhD,
p e r f o r m a lateral temporal bone resection and radical p a r o t i d e c t o m y encompassing the superficial lobe, deep lobe, and the facial n e r v e itself. Interpositional cable grafts are then inserted between the remaining trunk of the facial nerve and the peripheral branches previously tagged. The best source for the cable grafts are the sensory nerves f o u n d at the inferior portion of the neck or, a second choice, the sural nerve. A gold weight w o u l d be placed to protect the eye since, until, and if, function returns, the eye is at risk for injury. A modified neck dissection is p e r f o r m e d both for treatment and staging. I would also remove the skin overlying the tumor and excise it in continuity with the parotidectomy. Closure of this defect is best accomplished with a pectoral-cervical-facial rotation flap. I would r e c o m m e n d postoperative radiation because this is a poorly differentiated lesion with a violated t u m o r bed. The locoregional control rate w o u l d be increased with external b e a m r a d i o t h e r a p y using cobalt-60 with an electric b e a m boost to about 60 Gy. Because this is a p o o r l y differentiated lesion, any a d d e d adv a n t a g e of using n e u t r o n b e a m therapy is doubtful. REFERENCE 1. TranL, Sadeghi A, Hanson DG, et al: Major salivary gland tumors: Treatment results and prognostic factors. Laryngoscope 96: 1139-1144, 1986 Dr Myers: There are several flaws in the initial m a n a g e m e n t of this patient. The most outstanding is that there was no diagnosis m a d e before surgery. If a t u m o r involves the deep
OPERATIVE TECHNIQUES IN OTOLARYNGOLOGY--HEAD AND NECK SURGERY, VOL 7, NO 4 (DEC), 1996: PP 377-383
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FIGURE 1.
lobe and skin, one would have to suspect the presence of a malignant tumor. The dissection was clearly inadequate because 1 month after surgery, residual tumor is noted. An error in judgment/technique resulted in injury to the facial nerve. Whether this nerve has been resected or been injured in some other procedure is unclear. In my opinion, this patient should undergo radical surgery and postoperative adjunctive radiation therapy. Several issues should be addressed.
• Adequacy of resection. This surgery must include the residual tumor and the overlying skin, the masseter muscle, the periosteum of the mandible, the anterior cartilaginous external auditory meatus, the anterior aspect of the superior portion of the sternocleidomastoid muscle, and the posterior belly of the digastric muscle. • A modified radical neck dissection type 1 should be performed. The incidence of cervical lymph node metastasis in patients with high-grade mucoepidermoid carcinoma is higher than in any other malignant tumor of salivary gland origin. • Several types of reconstruction must be performed. The choices in order of my own preference would be the following: 378
Cervical-pectoral rotation flap (this would give the best color match and restore some bulk). Rectus abdominis free flap with split-thickness skin graft would provide bulk for contouring, but would be a poor color match. Facial nerve. The facial nerve should be resected with the main specimen. A mastoidectomy should be performed in order to identify the descending portion of the facial nerve. Frozen-section should be performed on the proximal resection margin of the nerve. Once adequate tumor clearance of the nerve has been achieved, a sural nerve graft or a graft taken from C4 (cervical plexus) should be used as a free graft. An effort should be made to identify the peripheral branches of the facial nerve, although 1 month after surgery, this may be very difficult to do because the nerves may not function even with electrical stimulation. If the branches can be identified, then the nerve graft should be anastomosed with the peripheral branches. If no branches can
be identified with certainty, then the nerve graft should be placed into the frontalis muscle of the orbicularis oculi muscle and the orbicularis oris muscle. A fascia lata sling would provide for a straight commissure in the event that nerve grafting was not performed, but is a poor second choice in my opinion. A gold weight should be placed in the upper eyelid to provide adequate eye closure whether or not the nerve can be reconstructed. The patient should receive postoperative adjunctive radiation therapy in order to neutralize the effect of cervical lymph node metastasis, facial nerve involvement and soft tissue extension, all of which are "aggressive" pathological findings. Neutron radiation has been shown to be useful in salivary gland tumors; however, there are only a few centers in this country in which this therapy is available and, although this treatment has been found to be efficacious, it may not be practical. Dr Spiro: In the absence of specific information, I assume that this patient had undergone a total parotidectomy with unintentional facial nerve DIFFICULT DECISIONS
injury or transection. Experienced surgeons m a y undertake a subtotal p a r o t i d e c t o m y in a clinically obvious setting without a preoperative needle aspiration biopsy (FNAB), but a histological diagnosis is essential (either preoperative FNAB or intraoperative frozen section) w h e n the findings suggest that the patient m a y require a more extensive procedure with greater risk to the facial nerve. The highly aggressive course in this case (ie, obvious recurrence within 1 month) is unusual even for poorly differentiated mucoepidermoid carcinoma. It indicates that gross residual t u m o r remained after inadequate initial surgery, a most u n h a p p y problem which is likely to defeat all subsequent efforts at salvage. If the recurrence is d e e m e d resectable, this patient's best chance for salvage w o u l d seem to be additional surgery followed b y postoperative radiation therapy (RT). The decision w h e t h e r to sacrifice overlying skin must be based on clinical evidence of dermal invasion. My preference for resurfacing is a large cervical rotat i o n / a d v a n c e m e n t flap, the incision for which is carried as far inferiorly on the anterior chest wall as necessary to allow the flap to reach the skin defect. Isolation of proximal and distal facial nerve branches 1 m o n t h after a "total" parotidectomy is likely to be a frustrating exercise with very limited prospect for good functional restoration by nerve grafting. I think it w o u l d be more reasonable to ignore the facial nerve during the second procedure, and insert a gold weight implant at the same sitting. Additional procedures for dynamic s u p p o r t can be considered later if locoregional control is achieved. Recognizing that resectability can be hard to assess, it w o u l d be wise to have the b r a c h y t h e r a p y team standing by. If gross t u m o r still remains after the re-resection, we have f o u n d that an implant placed in the area of concern, in conjunction with b e a m RT, can enhance t u m o r control. W h e n it is not clear that residual or recurrent salivary gland carcinoma can be completely resected, consideration should be given to neutron irradiation. Published data suggest that local control m a y be better than that which can be achieved by incom-
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plete surgery and p h o t o n irradiation.
CASE 2 A 58-year-old woman presents with a parotid tumor. Twenty years ago the mass was biopsied through the skin, and subtotal tumor resection was performed. The pathological report at that time was consistent with pleomorphic adenoma. The patient now presents with a 1-year history of multicentric recurrences. The tumor is fixed to the skin at several sites. A level II neck node is palpable. A fine-needle aspiration specimen is positive for pleomorphic adenoma. Questions What procedure is appropriate? Skin resection? If so, how should the skin be resurfaced? Should the deep lobe be addressed? Should postoperative radiation be used? Dr Abemayor: This patient suffers from a recurrent pleomorphic adenoma due to tumor spillage and inadequate excision. Such tumors are best considered as low-grade potentially aggressive neoplasms; even with further excisions, the patient is at risk for local recurrences with subsequent danger to facial function. I would begin by reviewing the prior operative note if possible. Was the t u m o r r e m o v e d b y enucleation or lateral lobectomy? This is important to k n o w because, in turn, it can tell us if the main trunk of the facial nerve was dissected out or not. In any event, extirpation of this tumor requires removal of all remaining parotid tissue and surrounding skin which is seeded with t u m o r cells. Under loupe magnification and using facial nerve monitoring, I w o u l d see if the main trunk of the nerve can be easily identified proximally. If not, I w o u l d find the peripheral branches (eye, buccal, marginal mandibular) and trace them back to the main trunk, removing any remaining superficial parotid tissue and residual tumor. Once the nerve is identified, the deep lobe tissue can also be removed. The level II n o d e and any other palpable nodes w o u l d be re-
m o v e d as a functional neck dissection. The involved cheek skin w o u l d be excised with resurfacing of the defect using a chest-cervical-cheek rotation flap. Due to this patient's relative youth, I w o u l d not use adjunctive radiation therapy for lesions that are still surgically resectable. For multiple recurrent lesions, I believe a radical parotidectomy with either pedicle or free flap muscle reconstruction is warranted.
REFERENCE 1. Conley JJ (ed): Problems with operation of the parotid gland and facial nerve. Otolaryngol Head Neck Surg 99:480-488, 1988 Dr Myers: The initial flaw in the m a n a g e m e n t of this patient was inadequate resection of the tumor. Patients w h o have been inadequately resected for pleomorphic a d e n o m a are at risk for recurrence of the pleomorphic adenoma or for development of carcinoma expleomorphic adenoma. The time sequence of 20 years after the initial surgery is possible in both instances. The fixation of the t u m o r to the skin and a palpable level II l y m p h node make one more suspicious about carcinoma exp l e o m o r p h i c a d e n o m a . The fineneedle aspiration specimen positive for pleomorphic a d e n o m a is not a guarantee that carcinoma ex-pleomorphic a d e n o m a is not present. I w o u l d r e c o m m e n d open biopsy of these nodules in order to establish a diagnosis. In m y experience, recurrent pleomorphic a d e n o m a can usually be adequately treated by total parotidectomy with facial nerve dissection. There is no mention about the condition of this patient's facial nerve, so for the sake of discussion, I assume that it is normal. If this is purely pleomorphic adenoma, I w o u l d excise the skin overlying several sites where the t u m o r is fixed to the skin and close these primarily. Removal of the t u m o r mass should provide e n o u g h additional skin in a 58-year-old w o m a n to close these areas primarily. During the time that the parotid is exposed, the level IF l y m p h node should be removed. This area is exposed during most parotid surgery, and by retracting the posterior belly
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of the digastric superiorly, the mass can be exposed and removed. If the initial biopsy revealed tumor in a lymph node, then one must conclude that this is malignant even though open biopsy of the primary tumor may have been diagnosed as pleomorphic adenoma on frozen section. If the tumor is adherent to the branches of the facial nerve, the individual branches should be resected and cable grafts should be applied. By extensive dissection posteriorly, the great auricular nerve, if it can be found, may be used. If not, then the fourth cervical nerve can be used, which is very helpful because it has multiple branches. If upon biopsy of the tumor mass, it is proven to be a carcinoma expleomorphic adenoma, then the patient's best interest would be best served by a complete resection of the entire parotid gland, the masseter muscle, the periosteum of the mandible, the facial nerve, and the overlying skin. If the facial nerve must be sacrificed, then replacement with sural nerve or cervical plexus nerve grafting may be performed. In the event that the mass is malignant, then a modified radical neck dissection should be performed. I don't believe in the use of radiation therapy for the treatment of benign tumors, although there is lit-
erature, particularly from the United Kingdom, on the routine treatment of pleomorphic adenoma, particularly recurrent, by radiation therapy. If this is a malignant tumor, then postoperative radiation therapy should be used as has been shown over many years that locoregional recurrence is improved even though the cure rate is not necessarily improved. Dr Spiro: The obvious explanation for the multifocal recurrence in this patient would seem to be seeding from the inappropriate "subtotal tumor resection" performed 20 years previously. The presence of a palpable level II lymph node, however, is troublesome despite the FNAB report of pleomorphic adenoma. It would be wise to aspirate the neck node. If this yielded tissue similar to that obtained from one of the parotid masses, the true diagnosis may actually prove to be malignant mixed tumor. Assuming the benign diagnosis is correct, an adequate subtotal parotidectomy with facial nerve sparing should be possible when the previous procedure has not exposed the nerve. There is no need for total parotidectomy unless the deep lobe is obviously involved. The patient needs to be especially well prepared
for the possibility of postoperative facial nerve dysfunction. In addition to the likelihood of direct nerve trauma during what often proves to be a more tedious dissection because of scarring, sacrifice of a nerve branch with cable grafting may occasionally be required when nerve and tumor are so intimately related that separation of the two will leave residual tumor. Dermal involvement from multifocal tumor recurrence poses a problem that is best resolved by excision of the overlying skin. Depending on the circumstance, resurfacing can be accomplished by split grafting, a cervical/facial rotation advancement flap (as mentioned previously) or free, revascularized tissue. Even with confidence in a benign diagnosis, it would be wise to excise the enlarged level II lymph node. If there is any question of malignant evolution of a benign pleomorphic adenoma, a limited lymphadenectomy (levels I, II, III) should be added to the parotidectomy. Recent experience suggests that adjunctive beam radiation therapy may offer enhanced locoregional control in patients with recurrent pleomorphic adenoma. Indications are far from clear, but the best results are obtained when it is given after a good debulking procedure that re-
FIGURE 2.
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DIFFICULT DECISIONS
FIGURE 3. moves all gross tumor. I n o w tend to use the RT sooner, rather than later. Even if a good cleanout is accomplished, this particular patient remains at high risk for another recurrence, at w h i c h time additional, nerve-sparing surgery is quite unlikely.
CASE 3 A 48-year-old woman has undergone right-sided parotidectomy twice for mixed tumor. She has a positive neck node, and results of fine-needle aspiration are positive for pleomorphic adenoma. CT scans are shown in Figs 2 and 3. Questions What procedure is appropriate? Should an external surgical approach be used, with or without cutting the mandible? A transoral approach? Or a combined external and transoral approach? Should postoperative radiation be administered? Dr A b e m a y o r : This patient has a r e c u r r e n t p a r a p h a r y n g e a l tumor. Most can be r e m o v e d through the neck; however, I also prepare the FRIEDMAN ET AL
patient for a possible m a n d i b u lotomy. This t u m o r is best approached through a transcervicaltransparotid route. In this fashion, the great vessels and the lower branches of the facial nerve are identified and protected, i prefer the approach popularized by Stell et al 1 and clearly described by Olsen. 2 In essence, this approach identifies at least the lower branches of the facial n e r v e out to the s u b m a n d i b u l a r gland. Once the sternocleidomastoid muscle is retracted laterally and cranial nerves X-XII are identified, the carotid artery and jugular vein are laterally retracted. Routing sacrifice of the external carotid artery is not always n e e d e d but can be done for a d d e d exposure. The angle of the mandible is retracted anteriorly and, if further exposure is needed, the submandibular gland is removed. With retraction of the mandible, the stylomandibular ligament is visualized and divided, resulting in a larger o p e n i n g into the p a r a p h a r y n g e a l space. For even more medial and superior exposure, m a n d i b u l o t o m y at the angle is added. In such cases, I first put the patient in maxillomandibular fixation using cortical bone screws at the nasal p y r i f o r m aperture and lower mandible. Before the
mandibulotomy, I contour a 4-hole compression plate for later use in mandibular fixation. Under direct visualization and with digital manipulation, the mass is removed. All attempts should be m a d e to preserve the integrity of the t u m o r ' s capsule. Intraoral excision is contraindicated because of possible infection, t u m o r seeding, or d a m a g e to vital vascular structures. T h r o u g h the transcervical approach, a s u p r a h y o i d neck dissection is possible to remove any l y m p h nodes or tumor-beading tissue. Because of the patient's age, i w o u l d reserve radiation for recurrent lesions not amenable to further surgical excision.
REFERENCES 1. Stell PH, Mansfield AO, Stoney PJ: Surgical approaches to tumors of the parapharyngeal space. Am J Oto]aryngol 6:92-97, 1988 2. Olsen KD: Tumors and surgery of the parapharyngeal space. LaryngoscopeSuppl 63:104, 1994 Dr Myers: This case presents a patient with a p a r a p h a r y n g e a l space extension of a deep lobe parotid tumor. These tumors arising from the deep lobe are, in m y experience, pleomorphic adenoma, carcinoma ex381
pleomorphic adenoma, or malignant mixed tumor. Although the fineneedle aspiration biopsy report is positive for pleomorphic adenoma, the possibility of carcinoma ex-pleomorphic adenoma or malignant mixed tumor is not necessarily established without adequate histopathology. The diagnosis is verified by the scan shown in Fig 3. One would have to be somewhat circumspect about the possibility of malignancy because the patient is said to have a "positive neck node." Because of the mention of this lymph node, this is a rather enigmatic situation. If the patient was known with certainty to have a pleomorphic adenoma, it should be removed through a parotid-submandibular approach in order to provide adequate exposure. The submandibular gland should be mobilized by ligating and transecting the facial artery posteriorly, and pedicaling the submandibular gland on the lingual nerve and the Wharton's duct. A total parotidectomy should be performed, carefully dissecting and preserving the facial nerve. This will allow adequate access to the deep lobe tumor and, by approaching it laterally from the exposure gained by a parotidectomy as well as the submandibular approach to the parapharyngeal space, the tumor can be removed, preserving the facial nerve. In my experience, a mandibulotomy approach is not necessary. A transoral approach, although it has been reported by Goodwin et al some years ago, 1 is potentially dangerous to the facial nerve in the resection of a deep lobe tumor, especially in a previously operated case. If this proves to be a malignant tumor, then postoperative radiation should be most certainly administered. REFERENCE 1. Goodwin WJ, Chandler JR: Transoral excision of lateral parapharyngeal space tumors presenting intraorall. Laryngoscope 98:266-269,1988 Dr Spiro: This patient's MRI shows a typical intraoral presentation of a deep lobe or retromandibular parotid tumor, which I would not expect to be palpable in the neck. If the
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"positive neck node" implies another, separate cervical mass, then I would have the same concerns about the possibility of malignant transformation that I expressed previously. I will always attempt transcervical resection of retromandibular parotid tumors with the patient prepared for the possibility of a paramedian mandibulotomy. The transcervical approach should start with exposure and identification of the facial nerve trunk and its ramus marginalis branch in order to avoid injury to these structures. If this access proves inadequate, which is seldom the case, the mandible is divided between the ipsilateral cuspid and lateral incisor. The paralingual incision is then carried up to the soft palate, which usually provides good external and transoral exposure. I believe that any attempt at direct transoral removal is ill-advised and inappropriate. Regardless of the approach, resection of deep lobe tumors entails a certain amount of blunt dissection. Given that margins are often minimal, I believe that postoperative irradiation is usually indicated in any patient whose lesion proves to be malignant. CASE 4 A 38-year-old HIV-positive man presents with a right-sided parotid mass with cervical nodes. Questions What imaging studies, if any, should be done? Should fineneedle aspiration be done? At surgery, is biopsy of the node alone required? Should a parotidectomy be done? Dr Abemayor: HIV-positive patients can develop benign lymphoepithelial cysts of the parotid that in reality are cystic, incompletely encapsulated lymph nodes. These patients are also prone to developing lymphomas that are amenable to medical therapy. Therefore, a diagnosis of these lesions is needed. I would begin with a contrast CT. Are other lesions visible in the contralateral parotid and neck? If so, this would strongly suggest a working diagnosis of "benign" HIV cysts.
I would also perform a fine-needle aspiration of the neck mass. In the hands of an experienced cytopathologist, a cell button can be prepared and lymphoma ruled in or out. If further definition of tissue type is needed, I could excise the neck mass. Cystic parotid lesions in HIVpositive patients act as inflammatory masses, making identification and preservation of the facial nerve difficult. Therefore, I would avoid a parotidectomy and concentrate on the cervical lymph nodes. REFERENCE 1. Finter MD, Schinella RA, Rothskin S, Persky M: Cysticparotid lesions in patients at risk for the Acquired Immunodeficiency Syndrome. Arch Otolaryngol Head Neck Surg 114:1290-1294,1988 Dr Myers: In my opinion, this patient has a lymphoepithelial lesion that is highly correlated with HIVpositivity. MRI scanning is usually helpful in such a case. Fine-needle aspiration biopsy should be performed. These lymphoepithelial cysts can be aspirated. Sometimes the cysts are painful and the patient is relieved of pain by repeat aspiration. Special precautions should be taken by the caregiver in order to avoid auto-inoculation of the HIV. It is not necessary or recommended that surgery be performed, and parotidectomy is contraindicated unless there is strong suspicion of associated malignancy. There is also a higher than expected incidence of lymphoma in HIV-infected patients and, if clinical behavior or adjunctive studies indicate the possibility of lymphoma, then open biopsy to establish this diagnosis should be performed. Dr Spiro- The association of parotid masses with seropositivity to HIV is now well recognized. Usually these are cystic and part of a pattern of generalized lymphadenopathy, which is often bilateral. FNAB of the parotid mass is indicated, and will probably yield turbid, amber, or milky fluid and cellular architecture similar to that observed in benign lymphoepithelial lesions. Limited surgery to remove the cystic mass may be appropriate in this setting, particularly when pain or discomfort are present. Other possibilities inDIFFICULT DECISIONS
clude a primary Kaposi's sarcoma arising in the parotid gland, or possibly even an unrelated primary carcinoma, either of which should be suggested by the FNAB findings. Parotidectomy is best avoided when the process is benign and HIV-related, unless the patient has multiple, symptomatic masses. In the presence of other, potentially lethal pathology, the extent of the indicated parotidectomy will depend on the stage and histology of the lesion, and neck dissection may also be required.
CASE 5 A 64-year-old man presents with a tumor at the tail of the parotid. Surgery discloses a 2 × 2 cm, relatively soft mass caudal to the marginal mandibular branch of the facial nerve (Fig 4).
Questions Are any imaging studies needed? Should a complete dissection be done along the distal aspects of the upper branches of the facial nerve (because this part of the gland is more than 4 cm away from the tumor)? Or will it be adequate to dissect the upper branches of the nerve just far enough to transect the gland and still provide wide margins away from the tumor?
Dr Abemayor: A contrast CT or MRI with gadolinium is helpful to inform the patient and prepare the patient and surgeon for a possible deep lobe or dumbbell parotid tumor. This is especially important, because the tumor is in the parotid tail. I would approach this tumor by finding the main trunk of the facial nerve inferior and medial to the tympanomastoid structure and then identifying the pes ansefinus distally. Given the tumor's inferior location, it is adequate to dissect the tumor off the inferior branches of the nerve and dissect the upper branches of the nerve just far enough to transect the gland. I believe this would provide adequate margins with minimal potential morbidity.
lower division of the facial nerve. I make an effort to ligate the Stensen's duct in order to prevent postoperative salivary fistula. The tumor can then be removed. Protecting the upper division without necessarily dissecting it, provides an efficient and effective way of dealing with these tumors. Dr Spiro: The information provided strongly suggests that this patient has a Warthin's tumor in the tail of his parotid gland. At issue is the question of preoperative evaluation and the type of operation to be performed. Although the clinical impression could be easily verified by FNAB or a technetium scan, I do not see a compelling indication for either procedure unless the surgeon has decided to perform a limited local excision, rather than a parotidectomy. I believe that a case can be made for less than a subtotal parotid resection with facial nerve dissection in carefully selected patients with small, benign tumors in the tail of the gland. An important caveat for those who would perform limited excision without nerve exposure is that the ramus marginalis branch is always closer than one might think. Although this can be minimized by nerve exposure and partial removal of the inferior portion of the gland lateral to it, there may be increased risk of salivary drainage following partial excision.
Dr Myers: This, in my experience, is a very common problem and this patient probably has a papillary cyst adenoma lymphomentosum (Warthin's tumor). Warthin's tumors commonly occur in the tail of the parotid. In my opinion, tumors in the tail of the parotid, whether they are Warthin's or other benign tumors, can be removed without dissecting the entire facial nerve or removing the entire superficial lobe of the parotid gland. I always identify the main trunk of the facial nerve as it exits the stylomastoid foramen, carry the dissection anteriorly until the bifurcation of the nerve is noted, and then dissection is continued along in order to expose the branches of the
Parot Glandid
TemporalBranch ~ ~~" ~ J ' ~~
Facial~ ~
terMuscl oc,e,i: e /j~ Tumor~-
ZygomaticBranch
~L~.~~
BuccalBranch
~
MandibularBranch
~
~'~~
~
Mandible
)~CervicalBranch ,-/
FIGURE 4.
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