- Email: [email protected]
Oral cavity and oropharynx squamous cell carcinoma with metastasis to the parotid lymph nodes
Oral Oncology 47 (2011) 142–144
Contents lists available at ScienceDirect
Oral Oncology journal homepage: www.elsevier.com/locate/oraloncology
Oral cavity and oropharynx squamous cell carcinoma with metastasis to the parotid lymph nodes q Steven M. Olsen, Eric J. Moore, Cody A. Koch, Jan L. Kasperbauer, Kerry D. Olsen ⇑ Department of Otolaryngology – Head and Neck Surgery, Mayo Clinic, Rochester, MN, United States
a r t i c l e
i n f o
Article history: Received 20 September 2010 Received in revised form 17 November 2010 Accepted 18 November 2010 Available online 22 December 2010 Keywords: Lymphatic metastasis Oral neoplasms Oropharynx carcinoma Parotid metastasis Parotid neoplasms Squamous cell carcinoma Oral cancer
s u m m a r y To increase awareness of the potential of oral and oropharyngeal squamous cell carcinoma (SCC) to metastasize to the parotid region. We retrospectively reviewed patients who had undergone parotidectomy for metastatic oral or oropharyngeal SCC at a single tertiary care facility from January 1988 to January 2004. Exclusion criteria were a history of cutaneous SCC of head and neck or extension of primary tumor into the parotid gland. Twelve patients met study criteria. Parotid metastasis represented the initial disease manifestation in 4 cases. In 1 case, parotid metastasis presented synchronously with the primary tumor. Parotid metastasis represented recurrent disease in the other 7 cases. Primary subsites included tongue base (n = 4), tonsil (n = 3), lateral pharyngeal wall (n = 2), oral floor (n = 1), maxillary alveolus (n = 1), and retromolar trigone (n = 1). Pathologic findings showed grade 3 or 4 SCC in all patients. Parotid metastasis was located in the inferior parotid nodes in 7 cases; multiple superficial nodes, 3 cases; and both deep and superficial nodes, 2 cases. Oral and oropharyngeal SCC can metastasize to the intraparotid lymph nodes. The inferior parotid nodes are most commonly involved, and patients generally have substantial associated cervical metastases. When treating patients who have oral or oropharyngeal cancer with substantial cervical metastasis, physicians should consider removing the inferior parotid lymph nodes. We recommend that when intraparotid lymph node metastasis is detected, total parotidectomy and multidisciplinary adjuvant therapy should be conducted. Ó 2010 Elsevier Ltd. All rights reserved.
Introduction The evaluation and treatment of masses in the parotid gland are important roles of the head and neck surgeon. A wide range of primary and metastatic neoplasms can present as masses in this gland. Most parotid gland neoplasms are primary. However, the intraparotid network of lymphatics places the parotid region at risk for lymph node metastasis. Parotid metastases most commonly occur from metastatic cutaneous cancers of the head and neck but may also arise from noncutaneous regions of the head and neck or from distant sites.1–3 Although uncommon, squamous cell carcinoma (SCC) of the upper aerodigestive tract may metastasize to the parotid gland. An awareness of this phenomenon is essential for the head and neck surgeon. Our clinical experience suggests that SCC of the upper aerodigestive tract with parotid metastasis most often arises from the oral cavity or oropharynx. However, the current medical literature
Abbreviation: SCC, squamous cell carcinoma. q
Presented at the Second World Congress of International Academy of Oral Oncology, Toronto, Ontario, Canada, July 8-11, 2009. ⇑ Corresponding author. Address: Department of Otolaryngology – Head and Neck Surgery, Mayo Clinic, 200 First St. SW, Rochester, MN 55905, United States. E-mail address: [email protected] (K.D. Olsen). 1368-8375/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.oraloncology.2010.11.010
contains only small series with 8 or fewer patients.1,4,5 We report the largest series, to our knowledge, of parotid metastasis from oral and oropharyngeal SCC. Our objectives are to increase awareness of the potential of oral and oropharyngeal SCC to metastasize to the parotid region, assess tumor characteristics that may help predict parotid metastasis, report oncologic outcomes of patients with metastatic SCC to the parotid gland, and provide a perspective on treatment. Methods This study was approved by the Mayo Clinic Institutional Review Board. The medical records of patients who underwent parotidectomy for metastatic SCC from oral or oropharyngeal sites between January 1988 and January 2004 were retrospectively reviewed. All patients had a diagnosis and received treatment at a single institution. Patients were included if they had a histologically confirmed oral or oropharyngeal SCC with metastasis to parotid lymph nodes. Patients were excluded if they had a history of either cutaneous head and neck SCC, a second primary SCC at a mucosal site outside the oral cavity or oropharynx, or direct tumor extension to the parotid gland. We reviewed patient demographics, clinical findings, treatment modality, and oncologic outcomes.
S.M. Olsen et al. / Oral Oncology 47 (2011) 142–144
Results Patient demographics During the study period, approximately 1500 patients with oral and oropharyngeal SCC were treated at our institution. Of these patients, 12 (0.8%) had parotid lymph node metastasis. The mean patient age was 58 years (range 40–93 years). Eleven of the patients were male. Ten patients were current or former smokers, and 2 patients did not have a documented smoking history. Tumor characteristics The location of the primary tumors included tongue base (n = 4), tonsil (n = 3), lateral pharyngeal wall (n = 2), floor of mouth (n = 1), maxillary alveolus (n = 1), and retromolar trigone (n = 1). A parotid mass represented the initial manifestation of disease in 4 of the 12 cases. In 1 case, parotid metastasis presented synchronously with symptoms of an oral cavity primary tumor. The patients in these 5 cases had stage IVA or IVB disease with N2b to N3 regional lymph node metastases. Parotid metastases developed in the other 7 patients at 12–61 months after treatment of a primary oral or oropharyngeal SCC. Histologic evaluation showed that all tumors were high grade (grade 3 or 4). A grade 4 adenosquamous variant was noted in 1 case. The most common location of metastases within the parotid gland was the inferior parotid nodes (tail of parotid). Inferior nodes were affected in 7 of the 12 patients. In addition, 3 patients had multiple positive nodes in the midportion of the superficial parotid lobe; the other 2 patients had positive nodes in both the superficial and deep parotid nodes. All patients had clinically palpable metastasis on physical examination. Treatment Ten patients underwent total parotidectomy and 2 patients with parotid-tail metastasis underwent partial parotidectomy. All 5 patients who originally presented with parotid metastasis received surgery and radiotherapy, and 2 of these patients also received chemotherapy. Among the 7 patients who presented with delayed metastasis, 5 had been previously treated with surgery alone and 2 had received surgery and radiotherapy. Treatment of the delayed parotid metastasis was surgery alone in 2 cases, surgery and radiotherapy in 4 cases, and surgery, radiotherapy, and chemotherapy in 1 case. Outcomes At last follow-up, 7 patients were dead of disease, 1 had died of infectious complications during chemotherapy, 2 were alive with no evidence of disease, 1 was alive with disease, and 1 was lost to follow-up at 9 months after treatment (Table 1). Among the 5 patients who initially presented with parotid metastasis, 2 were cured of disease and 3 had died of disease. Of the patients who presented with parotid metastasis as recurrent disease, 1 patient was lost to follow-up, 1 was alive with disease at 34 months, and the other 5 had died of disease. Discussion Parotid lymphatics An understanding of parotid embryology is important when considering the differential diagnosis of a parotid mass. The parotid glands arise during the sixth week of development from
143
outpouchings of the oropharyngeal ectoderm. During this period, regional mesoderm gives rise to the lymphatic system of the head and neck. The parotid gland encapsulates late in embryologic development, entrapping lymphatic tissue within the parotid capsule and parenchyma.2,4 The parotid lymphatics receive drainage from wide regions of the head and neck. Cutaneous sites that drain to the parotid lymphatics are the frontal, temporal, and malar skin; pinna and external acoustic meatus; upper lip; eyelids; and root of the nose. Mucosal and glandular regions that drain to the parotid lymphatics are the lacrimal gland, nasal fossa, oral cavity, laryngopharynx, eustachian tube, and middle ear.1,4,6 Parotid nodes are divided into superficial and deep groups on the basis of their relation to cranial nerve VII. Cadaveric studies confirm the presence of lymph nodes in superficial and deep lobes of the gland. The superficial lobe has 3.9–7.6 lymph nodes; the deep lobe has 1.05–2.3.6–9 These intraparotid lymphatics render the parotid uniquely susceptible to tumor metastasis.
Parotid metastasis of upper-aerodigestive-tract SCC Several small series have highlighted the potential for oral and oropharyngeal SCC to metastasize to the parotid gland. Conley and Arena1 presented 81 cases of parotid metastasis, of which 8 were SCC from oral and oropharyngeal primary tumors. In addition, they reported 3 cases of parotid metastasis from other head and neck mucosal sites, including 1 supralaryngeal cancer and 2 maxillary cancers. Pisani et al.5 reported a series of 10 patients who had parotid metastasis from cancers of the upper airway and digestive tract. In their series, 3 patients had tumors arising from the oropharynx. The other tumors arose from the larynx (n = 3), nasopharynx (n = 2), hypopharynx (n = 1), and maxillary sinus (n = 1). Ord et al.4 reported 2 cases of parotid gland recurrences from previously treated oral cavity SCC. To our knowledge, the present series represents the largest report to date of oral and oropharyngeal SCC that metastasizes to the parotid lymphatics. These cases illustrate the importance of a complete head and neck examination when a clinician evaluates patients with head and neck lesions. Five patients in the series presented with parotid metastasis before receiving treatment. In 4 cases, the parotid metastasis represented the initial presenting concern. Had the clinicians not performed complete head and neck examinations, the primary tumor may have been missed, causing treatment delays. The presentation of metastasis before neck treatment suggests that direct lymphatic connections may exist between the parotid gland and the oral cavity or the oropharynx. Alternatively, parotid metastases in these cases may have resulted from retrograde or aberrant lymphatic drainage occurring secondary to disruptions in normal lymphatic drainage due to extensive neck disease. All 5 patients presented with N2b or more advanced neck disease. Of the 7 patients who presented with delayed metastases, all had been treated previously with neck dissection, and 3 patients had received adjuvant radiotherapy. It is unclear whether the inferior parotid nodes were removed in these cases during the initial neck dissection. In the present series, parotid metastasis predominantly developed as recurrent, rather than initial, disease, supporting the supposition that parotid metastases from oral and oropharyngeal cancer occur more commonly after normal cervical lymphatic flow has been disrupted. Both radiotherapy and surgery have been shown to alter normal patterns of cervical lymph flow markedly.10 Alternatively, these nodal metastases may have been present as unrecognized microscopic metastasis at the time of initial tumor presentation.
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S.M. Olsen et al. / Oral Oncology 47 (2011) 142–144
Table 1 Location, stage, treatment, metastatic location, and oncologic outcome of the 15 tumors. Primary site
Primary TNM stage
Treatment of primary
Parotid metastasis, initial vs delayed
Stage at parotid recurrence
Parotid lymph node metastasis
Associated cervical metastasis
Outcome
Tonsil Tonsil Tongue base Retromolar trigone Tongue base
T1N2bM0 T2N2bM0 TisN2cM0 T4N2bM0a T2N3M0
Surgery/RT Surgery/RT Surgery/chemo-RT Surgery/chemo-RT Surgery/RT
Initial Initial Initial Initial Initial
NA NA NA NA NA
1 1 1 3 1
ANED 134 mo DOD 113 mo ANED 71 mo DOD 13 mo DOD 67 mo
Lateral pharyngeal wall Tongue base Tonsil Floor of mouth Tongue base
T1N0M0
Surgery
Delayed 31 mo
T0N1M0
1 Inferior
Ipsilateral level 2 Ipsilateral level 2 Bilateral level 2 Ipsilateral level 2, 5 Ipsilateral level 2, contralateral level 4 Negative neck
TxN1M0 TxN1M0 T1N1M0 T3N2bM0
Surgery/RT Surgery/RT Surgery Surgery
Delayed Delayed Delayed Delayed
mo mo mo mo
T2N2bM0 T4N2bM0 T2N2bM0 T0N2cM0
2 2 2 3
AWD 34 mo ANED 9 mo DOD 60 mo DOCb
Maxillary alveolus Lateral pharyngeal wall
T2N2bM0 T1N2bM0
Surgery Surgery/RT
Delayed 24 mo Delayed 42 mo
T0N2aM0 T0N2cM1
1 Inferior 1 Inferior
Ipsilateral level 2, 3 Ipsilateral level 2, 3 Negative neck Ipsilateral level 4, contralateral level 2, 3, 5 Negative neck Contralateral level 2, 3
15 61 41 12
Inferior Inferior Inferior Superficial Inferior
Superficial, 1 deep Inferior Inferior Superficial, 2 deep
DOD 81 mo
DOD 28 mo DOD 66 mo
Abbreviations: ANED, alive with no evidence of disease; AWD, alive with disease; chemo-RT, chemotherapy and radiotherapy; DOC, dead of other cause; DOD, dead of disease; NA, not applicable; RT, radiotherapy. a Histologic findings notable for grade 3 adenosquamous carcinoma. b Patient lost to follow-up at 9 months.
Treatment Providing clear treatment recommendations on the basis of a series of 12 patients is difficult, but some generalizations are possible. This study highlights the importance of a careful clinical and radiographic evaluation of the parotid region when the clinician examines a patient who has oral or oropharyngeal SCC and cervical metastasis. We advocate intraoperative evaluation of the parotid region when performing neck dissection. In this series, the parotid tail was the most commonly affected region of the parotid gland. During neck dissection, careful intraoperative inspection and palpation of the parotid should be performed. We recommend that when suspicion of metastatic involvement exists, removal of parotid tail nodes should occur. If metastasis is discovered in the parotid tail, we routinely recommend total parotidectomy. Facial nerve preservation is attempted unless the nerve is grossly involved with tumor. Controversy exists regarding the extent of surgery necessary to treat metastasis to parotid lymph nodes. Some surgeons recommend superficial parotidectomy, whereas others recommend total parotidectomy.7,11,12 In this study, among 10 patients who had total parotidectomy, 2 patients (20%) had pathologically identified metastasis in the deep lobe. On the basis of the frequency of deep-lobe metastases in this and other series7, we believe that total parotidectomy is necessary. Although total parotidectomy poses an increased risk of temporary facial nerve dysfunction, we generally accept this morbidity given the poor prognosis of untreated deep-lobe metastasis. Conclusion Oral cavity and oropharyngeal SCC can metastasize to the intraparotid lymph nodes. The inferior parotid nodes are most commonly involved. Affected patients generally present with bulky cervical metastasis or with parotid recurrences after treatment of an oral or oropharyngeal primary tumor. When treating patients
with oral or oropharyngeal cancer who have marked cervical metastasis, physicians should carefully evaluate and consider removing the inferior parotid lymph nodes. When intraparotid lymph node metastasis is discovered, we recommend an aggressive surgical approach with total parotidectomy and adjuvant therapy as indicated. Conflict of interest statement None declared. References 1. Conley J, Arena S. Parotid gland as a focus of metastasis. Arch Surg 1963;87:757–64. 2. Nuyens M, Schupbach J, Stauffer E, Zbaren P. Metastatic disease to the parotid gland. Otolaryngol Head Neck Surg 2006;135(6):844–8. 3. Ying YL, Johnson JT, Myers EN. Squamous cell carcinoma of the parotid gland. Head Neck 2006;28(7):626–32. 4. Ord RA, Ward-Booth RP, Avery BS. Parotid lymph node metastases from primary intra-oral squamous carcinomas. Int J Oral Maxillofac Surg 1989;18(2):104–6. 5. Pisani P, Krengli M, Ramponi A, Guglielmetti R, Pia F. Metastases to parotid gland from cancers of the upper airway and digestive tract. Br J Oral Maxillofac Surg 1998;36(1):54–7. 6. Nichols RD, Pinnock LA, Szymanowski RT. Metastases to parotid nodes. Laryngoscope 1980;90(8 Pt 1):1324–8. 7. Pisani P, Ramponi A, Pia F. The deep parotid lymph nodes: an anatomical and oncological study. J Laryngol Otol 1996;110(2):148–50. 8. Prins-Braam PM, Raaijmakers CP, Terhaard CH. Location of cervical lymph node metastases in oropharyngeal and hypopharyngeal carcinoma: implications for cranial border of elective nodal target volumes. Int J Radiat Oncol Biol Phys 2004;58(1):132–8. 9. Yarington Jr CT. Metastatic malignant disease to the parotid gland. Laryngoscope 1981;91(4):517–9. 10. Fisch UP. Cervical lymph flow in man following radiation and surgery. Trans Am Acad Ophthalmol Otolaryngol 1965;69(5):846–68. 11. Garatea-Crelgo J, Gay-Escoda C, Bermejo B, Buenechea-Imaz R. Morphological study of the parotid lymph nodes. J Craniomaxillofac Surg 1993;21(5):207–9. 12. McKean ME, Lee K, McGregor IA. The distribution of lymph nodes in and around the parotid gland: an anatomical study. Br J Plast Surg 1985;38(1):1–5.
Contents lists available at ScienceDirect
Oral Oncology journal homepage: www.elsevier.com/locate/oraloncology
Oral cavity and oropharynx squamous cell carcinoma with metastasis to the parotid lymph nodes q Steven M. Olsen, Eric J. Moore, Cody A. Koch, Jan L. Kasperbauer, Kerry D. Olsen ⇑ Department of Otolaryngology – Head and Neck Surgery, Mayo Clinic, Rochester, MN, United States
a r t i c l e
i n f o
Article history: Received 20 September 2010 Received in revised form 17 November 2010 Accepted 18 November 2010 Available online 22 December 2010 Keywords: Lymphatic metastasis Oral neoplasms Oropharynx carcinoma Parotid metastasis Parotid neoplasms Squamous cell carcinoma Oral cancer
s u m m a r y To increase awareness of the potential of oral and oropharyngeal squamous cell carcinoma (SCC) to metastasize to the parotid region. We retrospectively reviewed patients who had undergone parotidectomy for metastatic oral or oropharyngeal SCC at a single tertiary care facility from January 1988 to January 2004. Exclusion criteria were a history of cutaneous SCC of head and neck or extension of primary tumor into the parotid gland. Twelve patients met study criteria. Parotid metastasis represented the initial disease manifestation in 4 cases. In 1 case, parotid metastasis presented synchronously with the primary tumor. Parotid metastasis represented recurrent disease in the other 7 cases. Primary subsites included tongue base (n = 4), tonsil (n = 3), lateral pharyngeal wall (n = 2), oral floor (n = 1), maxillary alveolus (n = 1), and retromolar trigone (n = 1). Pathologic findings showed grade 3 or 4 SCC in all patients. Parotid metastasis was located in the inferior parotid nodes in 7 cases; multiple superficial nodes, 3 cases; and both deep and superficial nodes, 2 cases. Oral and oropharyngeal SCC can metastasize to the intraparotid lymph nodes. The inferior parotid nodes are most commonly involved, and patients generally have substantial associated cervical metastases. When treating patients who have oral or oropharyngeal cancer with substantial cervical metastasis, physicians should consider removing the inferior parotid lymph nodes. We recommend that when intraparotid lymph node metastasis is detected, total parotidectomy and multidisciplinary adjuvant therapy should be conducted. Ó 2010 Elsevier Ltd. All rights reserved.
Introduction The evaluation and treatment of masses in the parotid gland are important roles of the head and neck surgeon. A wide range of primary and metastatic neoplasms can present as masses in this gland. Most parotid gland neoplasms are primary. However, the intraparotid network of lymphatics places the parotid region at risk for lymph node metastasis. Parotid metastases most commonly occur from metastatic cutaneous cancers of the head and neck but may also arise from noncutaneous regions of the head and neck or from distant sites.1–3 Although uncommon, squamous cell carcinoma (SCC) of the upper aerodigestive tract may metastasize to the parotid gland. An awareness of this phenomenon is essential for the head and neck surgeon. Our clinical experience suggests that SCC of the upper aerodigestive tract with parotid metastasis most often arises from the oral cavity or oropharynx. However, the current medical literature
Abbreviation: SCC, squamous cell carcinoma. q
Presented at the Second World Congress of International Academy of Oral Oncology, Toronto, Ontario, Canada, July 8-11, 2009. ⇑ Corresponding author. Address: Department of Otolaryngology – Head and Neck Surgery, Mayo Clinic, 200 First St. SW, Rochester, MN 55905, United States. E-mail address: [email protected] (K.D. Olsen). 1368-8375/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.oraloncology.2010.11.010
contains only small series with 8 or fewer patients.1,4,5 We report the largest series, to our knowledge, of parotid metastasis from oral and oropharyngeal SCC. Our objectives are to increase awareness of the potential of oral and oropharyngeal SCC to metastasize to the parotid region, assess tumor characteristics that may help predict parotid metastasis, report oncologic outcomes of patients with metastatic SCC to the parotid gland, and provide a perspective on treatment. Methods This study was approved by the Mayo Clinic Institutional Review Board. The medical records of patients who underwent parotidectomy for metastatic SCC from oral or oropharyngeal sites between January 1988 and January 2004 were retrospectively reviewed. All patients had a diagnosis and received treatment at a single institution. Patients were included if they had a histologically confirmed oral or oropharyngeal SCC with metastasis to parotid lymph nodes. Patients were excluded if they had a history of either cutaneous head and neck SCC, a second primary SCC at a mucosal site outside the oral cavity or oropharynx, or direct tumor extension to the parotid gland. We reviewed patient demographics, clinical findings, treatment modality, and oncologic outcomes.
S.M. Olsen et al. / Oral Oncology 47 (2011) 142–144
Results Patient demographics During the study period, approximately 1500 patients with oral and oropharyngeal SCC were treated at our institution. Of these patients, 12 (0.8%) had parotid lymph node metastasis. The mean patient age was 58 years (range 40–93 years). Eleven of the patients were male. Ten patients were current or former smokers, and 2 patients did not have a documented smoking history. Tumor characteristics The location of the primary tumors included tongue base (n = 4), tonsil (n = 3), lateral pharyngeal wall (n = 2), floor of mouth (n = 1), maxillary alveolus (n = 1), and retromolar trigone (n = 1). A parotid mass represented the initial manifestation of disease in 4 of the 12 cases. In 1 case, parotid metastasis presented synchronously with symptoms of an oral cavity primary tumor. The patients in these 5 cases had stage IVA or IVB disease with N2b to N3 regional lymph node metastases. Parotid metastases developed in the other 7 patients at 12–61 months after treatment of a primary oral or oropharyngeal SCC. Histologic evaluation showed that all tumors were high grade (grade 3 or 4). A grade 4 adenosquamous variant was noted in 1 case. The most common location of metastases within the parotid gland was the inferior parotid nodes (tail of parotid). Inferior nodes were affected in 7 of the 12 patients. In addition, 3 patients had multiple positive nodes in the midportion of the superficial parotid lobe; the other 2 patients had positive nodes in both the superficial and deep parotid nodes. All patients had clinically palpable metastasis on physical examination. Treatment Ten patients underwent total parotidectomy and 2 patients with parotid-tail metastasis underwent partial parotidectomy. All 5 patients who originally presented with parotid metastasis received surgery and radiotherapy, and 2 of these patients also received chemotherapy. Among the 7 patients who presented with delayed metastasis, 5 had been previously treated with surgery alone and 2 had received surgery and radiotherapy. Treatment of the delayed parotid metastasis was surgery alone in 2 cases, surgery and radiotherapy in 4 cases, and surgery, radiotherapy, and chemotherapy in 1 case. Outcomes At last follow-up, 7 patients were dead of disease, 1 had died of infectious complications during chemotherapy, 2 were alive with no evidence of disease, 1 was alive with disease, and 1 was lost to follow-up at 9 months after treatment (Table 1). Among the 5 patients who initially presented with parotid metastasis, 2 were cured of disease and 3 had died of disease. Of the patients who presented with parotid metastasis as recurrent disease, 1 patient was lost to follow-up, 1 was alive with disease at 34 months, and the other 5 had died of disease. Discussion Parotid lymphatics An understanding of parotid embryology is important when considering the differential diagnosis of a parotid mass. The parotid glands arise during the sixth week of development from
143
outpouchings of the oropharyngeal ectoderm. During this period, regional mesoderm gives rise to the lymphatic system of the head and neck. The parotid gland encapsulates late in embryologic development, entrapping lymphatic tissue within the parotid capsule and parenchyma.2,4 The parotid lymphatics receive drainage from wide regions of the head and neck. Cutaneous sites that drain to the parotid lymphatics are the frontal, temporal, and malar skin; pinna and external acoustic meatus; upper lip; eyelids; and root of the nose. Mucosal and glandular regions that drain to the parotid lymphatics are the lacrimal gland, nasal fossa, oral cavity, laryngopharynx, eustachian tube, and middle ear.1,4,6 Parotid nodes are divided into superficial and deep groups on the basis of their relation to cranial nerve VII. Cadaveric studies confirm the presence of lymph nodes in superficial and deep lobes of the gland. The superficial lobe has 3.9–7.6 lymph nodes; the deep lobe has 1.05–2.3.6–9 These intraparotid lymphatics render the parotid uniquely susceptible to tumor metastasis.
Parotid metastasis of upper-aerodigestive-tract SCC Several small series have highlighted the potential for oral and oropharyngeal SCC to metastasize to the parotid gland. Conley and Arena1 presented 81 cases of parotid metastasis, of which 8 were SCC from oral and oropharyngeal primary tumors. In addition, they reported 3 cases of parotid metastasis from other head and neck mucosal sites, including 1 supralaryngeal cancer and 2 maxillary cancers. Pisani et al.5 reported a series of 10 patients who had parotid metastasis from cancers of the upper airway and digestive tract. In their series, 3 patients had tumors arising from the oropharynx. The other tumors arose from the larynx (n = 3), nasopharynx (n = 2), hypopharynx (n = 1), and maxillary sinus (n = 1). Ord et al.4 reported 2 cases of parotid gland recurrences from previously treated oral cavity SCC. To our knowledge, the present series represents the largest report to date of oral and oropharyngeal SCC that metastasizes to the parotid lymphatics. These cases illustrate the importance of a complete head and neck examination when a clinician evaluates patients with head and neck lesions. Five patients in the series presented with parotid metastasis before receiving treatment. In 4 cases, the parotid metastasis represented the initial presenting concern. Had the clinicians not performed complete head and neck examinations, the primary tumor may have been missed, causing treatment delays. The presentation of metastasis before neck treatment suggests that direct lymphatic connections may exist between the parotid gland and the oral cavity or the oropharynx. Alternatively, parotid metastases in these cases may have resulted from retrograde or aberrant lymphatic drainage occurring secondary to disruptions in normal lymphatic drainage due to extensive neck disease. All 5 patients presented with N2b or more advanced neck disease. Of the 7 patients who presented with delayed metastases, all had been treated previously with neck dissection, and 3 patients had received adjuvant radiotherapy. It is unclear whether the inferior parotid nodes were removed in these cases during the initial neck dissection. In the present series, parotid metastasis predominantly developed as recurrent, rather than initial, disease, supporting the supposition that parotid metastases from oral and oropharyngeal cancer occur more commonly after normal cervical lymphatic flow has been disrupted. Both radiotherapy and surgery have been shown to alter normal patterns of cervical lymph flow markedly.10 Alternatively, these nodal metastases may have been present as unrecognized microscopic metastasis at the time of initial tumor presentation.
144
S.M. Olsen et al. / Oral Oncology 47 (2011) 142–144
Table 1 Location, stage, treatment, metastatic location, and oncologic outcome of the 15 tumors. Primary site
Primary TNM stage
Treatment of primary
Parotid metastasis, initial vs delayed
Stage at parotid recurrence
Parotid lymph node metastasis
Associated cervical metastasis
Outcome
Tonsil Tonsil Tongue base Retromolar trigone Tongue base
T1N2bM0 T2N2bM0 TisN2cM0 T4N2bM0a T2N3M0
Surgery/RT Surgery/RT Surgery/chemo-RT Surgery/chemo-RT Surgery/RT
Initial Initial Initial Initial Initial
NA NA NA NA NA
1 1 1 3 1
ANED 134 mo DOD 113 mo ANED 71 mo DOD 13 mo DOD 67 mo
Lateral pharyngeal wall Tongue base Tonsil Floor of mouth Tongue base
T1N0M0
Surgery
Delayed 31 mo
T0N1M0
1 Inferior
Ipsilateral level 2 Ipsilateral level 2 Bilateral level 2 Ipsilateral level 2, 5 Ipsilateral level 2, contralateral level 4 Negative neck
TxN1M0 TxN1M0 T1N1M0 T3N2bM0
Surgery/RT Surgery/RT Surgery Surgery
Delayed Delayed Delayed Delayed
mo mo mo mo
T2N2bM0 T4N2bM0 T2N2bM0 T0N2cM0
2 2 2 3
AWD 34 mo ANED 9 mo DOD 60 mo DOCb
Maxillary alveolus Lateral pharyngeal wall
T2N2bM0 T1N2bM0
Surgery Surgery/RT
Delayed 24 mo Delayed 42 mo
T0N2aM0 T0N2cM1
1 Inferior 1 Inferior
Ipsilateral level 2, 3 Ipsilateral level 2, 3 Negative neck Ipsilateral level 4, contralateral level 2, 3, 5 Negative neck Contralateral level 2, 3
15 61 41 12
Inferior Inferior Inferior Superficial Inferior
Superficial, 1 deep Inferior Inferior Superficial, 2 deep
DOD 81 mo
DOD 28 mo DOD 66 mo
Abbreviations: ANED, alive with no evidence of disease; AWD, alive with disease; chemo-RT, chemotherapy and radiotherapy; DOC, dead of other cause; DOD, dead of disease; NA, not applicable; RT, radiotherapy. a Histologic findings notable for grade 3 adenosquamous carcinoma. b Patient lost to follow-up at 9 months.
Treatment Providing clear treatment recommendations on the basis of a series of 12 patients is difficult, but some generalizations are possible. This study highlights the importance of a careful clinical and radiographic evaluation of the parotid region when the clinician examines a patient who has oral or oropharyngeal SCC and cervical metastasis. We advocate intraoperative evaluation of the parotid region when performing neck dissection. In this series, the parotid tail was the most commonly affected region of the parotid gland. During neck dissection, careful intraoperative inspection and palpation of the parotid should be performed. We recommend that when suspicion of metastatic involvement exists, removal of parotid tail nodes should occur. If metastasis is discovered in the parotid tail, we routinely recommend total parotidectomy. Facial nerve preservation is attempted unless the nerve is grossly involved with tumor. Controversy exists regarding the extent of surgery necessary to treat metastasis to parotid lymph nodes. Some surgeons recommend superficial parotidectomy, whereas others recommend total parotidectomy.7,11,12 In this study, among 10 patients who had total parotidectomy, 2 patients (20%) had pathologically identified metastasis in the deep lobe. On the basis of the frequency of deep-lobe metastases in this and other series7, we believe that total parotidectomy is necessary. Although total parotidectomy poses an increased risk of temporary facial nerve dysfunction, we generally accept this morbidity given the poor prognosis of untreated deep-lobe metastasis. Conclusion Oral cavity and oropharyngeal SCC can metastasize to the intraparotid lymph nodes. The inferior parotid nodes are most commonly involved. Affected patients generally present with bulky cervical metastasis or with parotid recurrences after treatment of an oral or oropharyngeal primary tumor. When treating patients
with oral or oropharyngeal cancer who have marked cervical metastasis, physicians should carefully evaluate and consider removing the inferior parotid lymph nodes. When intraparotid lymph node metastasis is discovered, we recommend an aggressive surgical approach with total parotidectomy and adjuvant therapy as indicated. Conflict of interest statement None declared. References 1. Conley J, Arena S. Parotid gland as a focus of metastasis. Arch Surg 1963;87:757–64. 2. Nuyens M, Schupbach J, Stauffer E, Zbaren P. Metastatic disease to the parotid gland. Otolaryngol Head Neck Surg 2006;135(6):844–8. 3. Ying YL, Johnson JT, Myers EN. Squamous cell carcinoma of the parotid gland. Head Neck 2006;28(7):626–32. 4. Ord RA, Ward-Booth RP, Avery BS. Parotid lymph node metastases from primary intra-oral squamous carcinomas. Int J Oral Maxillofac Surg 1989;18(2):104–6. 5. Pisani P, Krengli M, Ramponi A, Guglielmetti R, Pia F. Metastases to parotid gland from cancers of the upper airway and digestive tract. Br J Oral Maxillofac Surg 1998;36(1):54–7. 6. Nichols RD, Pinnock LA, Szymanowski RT. Metastases to parotid nodes. Laryngoscope 1980;90(8 Pt 1):1324–8. 7. Pisani P, Ramponi A, Pia F. The deep parotid lymph nodes: an anatomical and oncological study. J Laryngol Otol 1996;110(2):148–50. 8. Prins-Braam PM, Raaijmakers CP, Terhaard CH. Location of cervical lymph node metastases in oropharyngeal and hypopharyngeal carcinoma: implications for cranial border of elective nodal target volumes. Int J Radiat Oncol Biol Phys 2004;58(1):132–8. 9. Yarington Jr CT. Metastatic malignant disease to the parotid gland. Laryngoscope 1981;91(4):517–9. 10. Fisch UP. Cervical lymph flow in man following radiation and surgery. Trans Am Acad Ophthalmol Otolaryngol 1965;69(5):846–68. 11. Garatea-Crelgo J, Gay-Escoda C, Bermejo B, Buenechea-Imaz R. Morphological study of the parotid lymph nodes. J Craniomaxillofac Surg 1993;21(5):207–9. 12. McKean ME, Lee K, McGregor IA. The distribution of lymph nodes in and around the parotid gland: an anatomical study. Br J Plast Surg 1985;38(1):1–5.