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INTRATHORACIC NERVE SHEATH TUMOR OF THE VAGUS
INTRATHORACIC NERVE SHEATH T U M O R OF THE VAGUS Giorgio Gayola, M.D.,* Michel Janis, M.D.,** Peter H. Weil, M.D.,***
N
New York, N.
and
Y.
tumors of the mediastinum are frequent and constitute the majority of the neoplasms of the posterior mediastinum. Those originating from the vagus nerve are rare. This report will be limited to tumors arising from the nerve sheath. In a survey of the literature, we found only 19 eases of this type of tumor. We believed that it would be of interest to add 1 case and to discuss the problems in diagnosis and treatment, with a plea for "conserva tive" surgery. EUROGENIC
CASE REPORT D.S., a 35-year-old, white, asymptomatic man, was first admitted to The Bronx Municipal Hospital Center in May, 1960, because of a mediastinal mass seen on a pre-employment chest film in January, 1960. A previous roentgenogram made in 1958 was reported as normal. Past history was essentially negative except for pneumonia and convulsive disease in child hood. On physical examination, the salient findings were as follows: asthenic habitus with mild pectus excavatum; a Grade 1 systolic murmur at the apex; blood pressure of 140/80 mm. H g ; pulse of 80; electrocardiogram which showed incomplete right bundle branch block. Chest film and tomography (Fig. 1) revealed a well-defined, homogeneous density situated in the right superior mediastinum, intimately related to the trachea which was slightly indented upon and displaced to the opposite side. An angiogram indicated no relationship to the heart or great vessels. Barium swallow, thyroid scan, and bronchoscopy were all normal. Excisional therapy was advised, but the patient refused. He was readmitted in October, 1961, complaining of recent episodes of cough, nausea, and vomiting which promptly subsided without specific therapy. Roentgenograms again showed the mediastinal density with no significant changes. With the preoperative diagnosis of superior mediastinal tumor, most likely a dermoid, a right posterolateral thoracotomy was performed on Nov. 6, 1961. Lying directly under neath the mediastinal pleura was an ovoid, soft mass, 3.5 by 2 cm. I t was well encapsulated and clearly originated from the right vagus nerve, the fibers of which appeared to enter and leave the upper and lower poles of the tumor. The recurrent laryngeal nerve branched off j u s t proximal to the tumor and was adherent to its upper pole but was preserved by dissecting its fibers off the tumor. The mass was easily removed by sharp dissection, with From the Departments of Surgery and Pathology, Albert Einstein College of Medicine, and The Bronx Municipal Hospital Center, New York, N. Y. Received for publication July 21, 1964. "■Instructor and formerly Chief Resident in Thoracic Surgery. **Assistant Professor of Pathology. *** Assistant Professor of Surgery. 412
Vol. 49, No. 3 March, 1965
INTRATHOEACIC NERVE SHEATH TUMOR
413
Fig. 1.—Roentgenogram (left) and tomogram (right) of the chest show density in right superior mediastinum.
Fig. 2.- -The cross section of the tumor. Note a distinct investing capsule, the shiny gray areas,
and zones of hemorrhage.
transsection of the vagus nerve just above and below it. At no time during the procedure or in the immediate postoperative period was there any significant elevation of the blood pressure or pulse rate. The vagal stumps were tied with fine silk and not approximated. Frozen section revealed a benign nerve sheath tumor. The chest was then closed in routine fashion. I n the postoperative course, hoarseness and paralysis of the right vocal cord were noted. The patient was unable to cough efficiently and developed atelectasis of the right lower lobe which cleared after bronchoscopic aspirations. He was discharged on the fifteenth day. At follow-up visits, the patient has been asymptomatic and is no longer hoarse. Both vocal cords moved well 6 months after surgery.
QAYOLA, J A N I S , W E I L
414
J. Thoracic and Cardiovas. Surg.
Gross and Histologic Examinations.—The specimen was an oval, shiny gray mass, measuring 3.5 cm. by 2 cm. in greatest diameters, which was invested by a delicate fibrous capsule (Fig. 2 ) . At one pole, blending with the capsule, there was a string-like structure 8 mm. in length, apparently a portion of nerve. The specimen was of soft, somewhat cystic, consistenay. The cut surface was gray and glistening in one third of the specimen, while in the other two thirds it was variegated, hemorrhagic with scattered yellow opaque areas. Microscopically, the lesion was composed of spindle-shaped cells, scattered loosely in a myxoid stroma. Within the stroma there were occasional nerve bundles and numerous vessels with thick collagen collars and frequent microcysts. Some sections showed recent and old hemor rhage. A distinct fibrous capsule surrounded the lesion (Fig. 3 ) . Diagnosis: Neurofibroma of vagus nerve, right (intrathoracic).
Fig. 3.—Characteristic microscopic appearance—spindle-shaped cells scattered in loose mixoid stroma.
DISCUSSION
Vagus tumors of the head and neck area, of which there are the larger number in the literature, will not be discussed in this report. Among the 19 eases of intrathoracic vagus sheath tumors previously reported (Table I 1 " 12 ), 5 are classified as schwannomas (neurilemmomas), 7 ' 10 ' 12 11 as neurofibromas, 1 ' 4 " 9 ' "■ 1 2 2 as "neurinomas," 2 and 1 as neurofibrosarcoma.3 Of the 11 neurofibromas, at least 61' 4>7>fl> 12 were definitely and 2 more11 were probably associated with von Recklinghausen's disease, including the first case reported by Blades and Dugan 1 in which the tumors were multiple, appearing in a string-like fashion along the nerve. Neurilemmomas (schwannomas) consist of Antoni A type tissue with palisading of nuclei and Verocay bodies, or loose Antoni B type tissue with microcysts; they are encapsulated and prone to de-
INTRATHOEACIC NERVE SHEATH TUMOR
Vol. 49, No. 3 March, 1965
415
generation. Neurofibromas have a poorly organized microscopic structure and neurites. They are distinctly different from neurogenic sarcomas. The exact location of the tumor in its relation to the recurrent laryngeal nerve was not stated in every reported case. In 5 cases,1' °'8> 9 including our own, the tumor or tumors were definitely below the recurrent laryngeal nerve and the latter was preserved. In 1 case reported by Gilbertsen and Lillehei5 the tumors were bilateral; there was no evidence of von Recklinghausen's disease and the lesions were diagnosed as neurofibromas. The authors did sacrifice the recurrent laryngeal nerve on one side but preserved the contralateral one. In 4 other cases the authors state that the recurrent laryngeal nerve was involved and had to be resected.2- 4> ll>.12 Of 4 cases collected at the Mayo Clinic by Penido and associates,7 3 were intrathoracic benign schwannomas and 1 was TABLE I.
INTRATHORACIC VAGUS S H E A T H TUMORS
HISTOLOGY
VON RECKLINGHAUSEN 'S DIS.
SEX
AGE
M
35
Neurofibroma
Yes
Left, multiple, below recurrent laryngeal nerve
Efskind & Liavaag 2
F M
52 35
Neurinoma Neurinoma
No No
Not specified Left recurrent laryngeal nerve (interlobar)
Parellas
M
51
Neurofibrosarcoma (?)
No
Right, cervieothoracic
Gerbode & Marguiles 4
M
24
Neurofibroma
Yes
Left, multiple, vagus and recur rent laryngeal nerve
Gilbertsen & Lillehei 5
M
40
Neurofibroma
No
Bilateral, above and below recur rent laryngeal nerve
Tuttle et al.«
M
30
Neurofibroma
No
Left, below recurrent laryngeal nerve
Penido et al. 7
M P F M
6 39 56 30
Neurofibroma Schwannoma Schwannoma Schwannoma
Yes No No No
Left, 1nultiple, mid-portion Left 1 One above, two Right below recurrent Right. laryngeal nerve
Davis & Browns
F
55
Neurofibroma
No
Left, below recurrent laryngeal nerve
Pampari et al. 9
F
67
Neurofibroma
Yes
Right, below recurrent laryngeal nerve
Carey et al. 1 0
F
Left, recurrent laryngeal nerve
AUTHORS
Blades & Dugan
1
Oberman & Abell 1 1 Ecker et al.12
Gayola et al.
45 ? ?
Schwannoma
No
Neurofibroma Neurofibroma
? ?
SIDE AND LOCATION
M
35
Neurilemmoma
No
M F
47 30
Neurofibroma Neurofibroma
Yes Yes
Left, from apex to hilum, involv. recurrent laryngeal nerve Right, vagus above carina Left, vagus below aortic arch; also tumor of fourth inter costal nerve
M
35
Neurofibroma
No
Right, below recurrent laryngeal nerv e
416
GAYOLA, J A N 1 8 ,
WEIL
J. Thoracic and Cardiovas. Surg.
a neurofibroma with neurofibromatosis. The authors state that one of the tumors was located above, two others below the recurrent laryngeal nerve, and one at the level of the arch of the aorta. They do, however, not state whether or not the recurrent laryngeal nerves were sacrificed in these cases. Two of these cases are included in Carey's series.10 In another case reported by Parella 3 in 1950, a cervicothoracic tumor of the left vagus nerve was partially removed by a combined cervical and thoracic approach as the multinodular growth was found to extend into the mediastinum. This tumor was classified as a neurofibrosarcoma with hemangioma. We wonder, however, if it might not have been benign since an inquiry at the respective hospital revealed that the patient was alive and well 6 years after the operation. This would have been the only malignant intrathoracic tumor of the vagus that we were able to find in the literature. Two malignant vagus sheath tumors reported by Furrer and Fox 13 and Penido 7 were located in the neck and did not extend into the chest. Stout 14 in 1935 reviewed 194 cases of tumors of the peripheral nerves and added 50 new cases. He found only one instance of malignancy and suggested that therapy should be surgical removal, with preservation of the fibers of the larger nerves, if possible, by dissecting out the tumor. No tumors originating from the intrathoracic portion of the vagus are listed in his series, but the observation is made which is also confirmed by other authors 15 ' 16 that there is a higher incidence of malignancy in neurogenic tumors associated with von Recklinghausen's disease. In reviewing other series we did not find reports of intrathoracic vagus tumors,16"25 although from its location, at least one of the tumors reported by Tebow and Brown19 might have originated from the vagus nerve. On the whole, neurogenic mediastinal tumors exhibit a paucity of symptoms. Only occasionally, cough, hoarseness, dysphagia have been present due to com pression of adjacent structures. In 1 case, epigastric distress and cramps were said to have disappeared after resection, but there is no clear evidence that the growth provokes abnormal stimuli. In this respect, there have been recent re ports in the literature indicating that pulmonary hvpertrophic osteoarthropathy may be related to abnormal impulses traveling via the afferent vagal fibers.26 No anatomical changes characteristic of osteoarthropathy have been described in any of the patients with vagal sheath tumors, some of which have, no doubt, been present for years. Unilateral resection of the vagus in the upper medias tinum is tolerated without ill effects; the only complication arises from the interruption of the recurrent laryngeal nerve. Preoperatively, they represent the usual differential diagnostic problems of mediastinal tumors. After vascular lesions are ruled out by angiography, the diagnosis is usually made at the time of operation. The postoperative pulmonary complications are, in our opinion, at least as much due to inefficient coughing from a paralyzed cord added to a thoracotomy incision, as to a questionably altered ciliary action, bronchial peristalsis, and mucous secretions from the interruption of the parasympathetie fibers, as suggested by Gilbertsen and Lillehei.5 In the discussion of this case we would like to stress two points. First, that one can recognize the benign nature of the lesion at the time of surgery and, second, that conservatism in resection is justified once the diagnosis of benignity
Vol. 49, No. 3 March, 1965
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417
is established. A diagnosis of benign neurogenic tumor can be made by gross examination and frozen section. In our case, the following features were of help in making this diagnosis. The lesion was definitely recognized as being part of the vagus nerve; there was a distinct capsule; the cross section exhibited shiny, light gray, semitranslueent edematous tissue with scattered blood-filled cystic structures. On frozen section one was impressed by the numerous thick-walled blood vessels within a loose fibrillar stroma and loosely packed cells, absence of dense cellular areas, no areas with definite anaplasia of cellular elements. On frozen section the lesion was interpreted as benign neurogenic tumor, probably neurilemmoma. If Antoni type A tissue with Verocay bodies could have been identified, the benign nature of the lesion would have become even more ap parent. On permanent sections the above features were confirmed; however, one could identify nerve fibers within the substance of the tumor and not only in the capsule, which suggests that the lesion was probably a neurofibroma. Al though these fine points of differentiation between neurilemmoma and neuro fibroma are of importance to the pathologist, they do not appear crucial at time of operation when the decision lies between benignity and malignancy. Had the tumor been malignant, a more extensive resection would have been undertaken and the recurrent laryngeal nerve would have been sacrificed. We feel, however, that the decision to sacrifice or preserve important adjacent, struc tures in these cases should not be based on the mere possibility of malignancy. We disagree with Ecker and his co-workers that sacrifice of the vagus nerve and its branches beyond the limit of the tumor is indicated, particularly in view of their own statement that the prognosis of these lesions is excellent since malignant degeneration is not an important consideration.12 When the tumor is proximal to the recurrent laryngeal nerve, the function of the latter cannot be saved. But whenever the tumor arises distal to the recurrent laryngeal nerve, the latter should be preserved even if it is intimately adherent to the tumor. Other important structures in the chest, to which the tumor may be adherent, should also be preserved. SUMMARY
A case of intrathoracic tumor of the vagus sheath is presented with a review of the literature. The benign nature of the lesion can be established with reason able certainty at the time of operation from gross appearance and frozen sec tion. We, therefore, believe that a conservative resection is indicated, particu larly when an important structure, such as the recurrent laryngeal nerve, can be preserved. One rarely encounters malignant tumors of the peripheral nerves and, particularly, of the vagus nerve. REFERENCES 1. Blades, B., and Dugan, D. .T.: Resection of Left Vagus Nerve for Multiple Intra thoracic Neurofibromaa, J. A. M. A. 123: 409, 1943. 2. Efskind, L., and Liavaag, K.: Intrathoracic Neurogenic Tumors, J . THORACIC STJEG. 20: 13, 1950. 3. Parella, G. S.: Neurofibrosarcoma of the Vagus Nerve, New England J . Med. 242: 324, 1950.
418
GAYOLA, J A N I S , W E I L
J. Thoracic and Cardiovas. Surg.
4. Gerbode, F., and Marguiles, G. S.: Neurofibromatosis W i t h Intrathoracic Neurofibromas of Vagus Nerve, J . THORACIC SURG. 2 5 : 429, 1953.
5. Gilbertsen, V. A., and Lillehei, C. W.: Bilateral I n t r a t h o r a c i c Neurofibromas of the Vagus Nerve With a Note on t h e Physiologic Effects of Cervicothoracic Vagectomy in M a n : A Case Report, J . THORACIC SURG. 28: 78, 1954. 6. Tuttle, W. M., Sanai, V., and Harms, H . P . : Intrathoracic Neurofibroma of t h e Vagus N e r v e , J . THORACIC SURG. 31: 632, 1956.
7. Penido, J . B . F . , and others: Tumors of t h e Vagus Nerve, Proc. Staff Meet. Mayo Clin. 32: 239, 1957. 8. Davis, C , J r . , and Brown, G.: Intrathoracic Neurofibroma of t h e Vagus Nerve Associ ated With a Diaphragmatic Hernia, J . THORACIC SURG. 33: 532, 1957. 9. Pampari, D., a n d Lacerenza, C : A Case of Neurofibroma of t h e Intrathoracic Vagus Nerve in a Woman With Eecklinghausen's Disease, Surgery 45: 470, 1959. 10. Carey, L . S., Ellis, F . H., J r . , Good, C. A., and Woolner, L. B . : Neurogenic Tumors of the Mediastinum: A Clinicopathologic Study, Am. J . Eoentgenol. 84: 189, 1960. 11. Oberman, H. A., and Abell, M. E . : Neurogenous Neoplasms of the Mediastinum, Cancer 13: 882, 1960. 12. Eeker, E . E., Timmes, J . J., and Miscall, L . : Neurogenic Tumors of t h e Intrathoracic Vagus Nerve, Arch. Surg. 86: 222, 1963. 13. Furrer, E . D., and Fox, I . E . : Perineural Fibrosarcoma of t h e Left Vagus Sheath, West. J . Surg. 48: 584, 1940. 14. Stout, A. P., a n d Carson, W . : The Peripheral Manifestations of. t h e Specific Nerve Sheath Tumor (Neurilemmoma), Am. J . Cancer 24: 751, 1935. 15. Hosoi, K . : Multiple Neurofibromatosis (von Eecklinghausen's Disease) With Special Eeference to Malignant Transformation, Arch. Surg. 22: 258, 1931. 16. Ackerman, L . V., a n d Taylor, F . H . : Neurogenous Tumors Within t h e Thorax: A Clinicopathological Evaluation of 48 Cases, Cancer 4: 669, 1951. 17. Harrington, S. W . : Surgical Treatment in 14 Cases of Mediastinal or Intrathoracic P e r i n e u r a l Fibroblastoma, J . THORACIC SURG. 3 : 590, 1934.
18. Kent, E . M., Blades, B., Valle, A. E., a n d Graham, E . A.: Intrathoracic Neurogenic Tumors, J . THORACIC SURG. 13: 116, 1944.
19. Tebow, L. E., and Brown, E . B . : Neurogenic Tumors of t h e Anterior and Middle Mediastinum, Am. Surgeon 19: 491, 1953. 20. Even, E., and others: Les schwannomes mediastino-pleuraux malins et diffus, J . fran§. med. et chir. thorac. 12: 450, 1958. 21. Urso, L., and others: I ganglioneuromi del mediastino, Ann. I t a l . chir. 35: 353, 1958. 22. Bergmann, F . : L e s neurinomes; propos cliniques, Acta chir. Belg. 58: 215, 1959. 23. Soliani, F . : Neurinomi primitivi intra-polmonari, Policlin. 6 6 : 51, 1959. 24. Bucolossi, P., and others: I tumori neurogenici del mediastino, Tumori (Milano) 4 5 : 113, 1959. 25. Daniel, E . A., J r . , and others: Mediastinal Tumors, Ann. Surg. 151: 783, 1960. 26. Holling, H . E., Brodey, E . S., and Boland, H . C : Pulmonary Hypertrophic Osteoarthropathy, Lancet 2 : 1269, 1961.
N
New York, N.
and
Y.
tumors of the mediastinum are frequent and constitute the majority of the neoplasms of the posterior mediastinum. Those originating from the vagus nerve are rare. This report will be limited to tumors arising from the nerve sheath. In a survey of the literature, we found only 19 eases of this type of tumor. We believed that it would be of interest to add 1 case and to discuss the problems in diagnosis and treatment, with a plea for "conserva tive" surgery. EUROGENIC
CASE REPORT D.S., a 35-year-old, white, asymptomatic man, was first admitted to The Bronx Municipal Hospital Center in May, 1960, because of a mediastinal mass seen on a pre-employment chest film in January, 1960. A previous roentgenogram made in 1958 was reported as normal. Past history was essentially negative except for pneumonia and convulsive disease in child hood. On physical examination, the salient findings were as follows: asthenic habitus with mild pectus excavatum; a Grade 1 systolic murmur at the apex; blood pressure of 140/80 mm. H g ; pulse of 80; electrocardiogram which showed incomplete right bundle branch block. Chest film and tomography (Fig. 1) revealed a well-defined, homogeneous density situated in the right superior mediastinum, intimately related to the trachea which was slightly indented upon and displaced to the opposite side. An angiogram indicated no relationship to the heart or great vessels. Barium swallow, thyroid scan, and bronchoscopy were all normal. Excisional therapy was advised, but the patient refused. He was readmitted in October, 1961, complaining of recent episodes of cough, nausea, and vomiting which promptly subsided without specific therapy. Roentgenograms again showed the mediastinal density with no significant changes. With the preoperative diagnosis of superior mediastinal tumor, most likely a dermoid, a right posterolateral thoracotomy was performed on Nov. 6, 1961. Lying directly under neath the mediastinal pleura was an ovoid, soft mass, 3.5 by 2 cm. I t was well encapsulated and clearly originated from the right vagus nerve, the fibers of which appeared to enter and leave the upper and lower poles of the tumor. The recurrent laryngeal nerve branched off j u s t proximal to the tumor and was adherent to its upper pole but was preserved by dissecting its fibers off the tumor. The mass was easily removed by sharp dissection, with From the Departments of Surgery and Pathology, Albert Einstein College of Medicine, and The Bronx Municipal Hospital Center, New York, N. Y. Received for publication July 21, 1964. "■Instructor and formerly Chief Resident in Thoracic Surgery. **Assistant Professor of Pathology. *** Assistant Professor of Surgery. 412
Vol. 49, No. 3 March, 1965
INTRATHOEACIC NERVE SHEATH TUMOR
413
Fig. 1.—Roentgenogram (left) and tomogram (right) of the chest show density in right superior mediastinum.
Fig. 2.- -The cross section of the tumor. Note a distinct investing capsule, the shiny gray areas,
and zones of hemorrhage.
transsection of the vagus nerve just above and below it. At no time during the procedure or in the immediate postoperative period was there any significant elevation of the blood pressure or pulse rate. The vagal stumps were tied with fine silk and not approximated. Frozen section revealed a benign nerve sheath tumor. The chest was then closed in routine fashion. I n the postoperative course, hoarseness and paralysis of the right vocal cord were noted. The patient was unable to cough efficiently and developed atelectasis of the right lower lobe which cleared after bronchoscopic aspirations. He was discharged on the fifteenth day. At follow-up visits, the patient has been asymptomatic and is no longer hoarse. Both vocal cords moved well 6 months after surgery.
QAYOLA, J A N I S , W E I L
414
J. Thoracic and Cardiovas. Surg.
Gross and Histologic Examinations.—The specimen was an oval, shiny gray mass, measuring 3.5 cm. by 2 cm. in greatest diameters, which was invested by a delicate fibrous capsule (Fig. 2 ) . At one pole, blending with the capsule, there was a string-like structure 8 mm. in length, apparently a portion of nerve. The specimen was of soft, somewhat cystic, consistenay. The cut surface was gray and glistening in one third of the specimen, while in the other two thirds it was variegated, hemorrhagic with scattered yellow opaque areas. Microscopically, the lesion was composed of spindle-shaped cells, scattered loosely in a myxoid stroma. Within the stroma there were occasional nerve bundles and numerous vessels with thick collagen collars and frequent microcysts. Some sections showed recent and old hemor rhage. A distinct fibrous capsule surrounded the lesion (Fig. 3 ) . Diagnosis: Neurofibroma of vagus nerve, right (intrathoracic).
Fig. 3.—Characteristic microscopic appearance—spindle-shaped cells scattered in loose mixoid stroma.
DISCUSSION
Vagus tumors of the head and neck area, of which there are the larger number in the literature, will not be discussed in this report. Among the 19 eases of intrathoracic vagus sheath tumors previously reported (Table I 1 " 12 ), 5 are classified as schwannomas (neurilemmomas), 7 ' 10 ' 12 11 as neurofibromas, 1 ' 4 " 9 ' "■ 1 2 2 as "neurinomas," 2 and 1 as neurofibrosarcoma.3 Of the 11 neurofibromas, at least 61' 4>7>fl> 12 were definitely and 2 more11 were probably associated with von Recklinghausen's disease, including the first case reported by Blades and Dugan 1 in which the tumors were multiple, appearing in a string-like fashion along the nerve. Neurilemmomas (schwannomas) consist of Antoni A type tissue with palisading of nuclei and Verocay bodies, or loose Antoni B type tissue with microcysts; they are encapsulated and prone to de-
INTRATHOEACIC NERVE SHEATH TUMOR
Vol. 49, No. 3 March, 1965
415
generation. Neurofibromas have a poorly organized microscopic structure and neurites. They are distinctly different from neurogenic sarcomas. The exact location of the tumor in its relation to the recurrent laryngeal nerve was not stated in every reported case. In 5 cases,1' °'8> 9 including our own, the tumor or tumors were definitely below the recurrent laryngeal nerve and the latter was preserved. In 1 case reported by Gilbertsen and Lillehei5 the tumors were bilateral; there was no evidence of von Recklinghausen's disease and the lesions were diagnosed as neurofibromas. The authors did sacrifice the recurrent laryngeal nerve on one side but preserved the contralateral one. In 4 other cases the authors state that the recurrent laryngeal nerve was involved and had to be resected.2- 4> ll>.12 Of 4 cases collected at the Mayo Clinic by Penido and associates,7 3 were intrathoracic benign schwannomas and 1 was TABLE I.
INTRATHORACIC VAGUS S H E A T H TUMORS
HISTOLOGY
VON RECKLINGHAUSEN 'S DIS.
SEX
AGE
M
35
Neurofibroma
Yes
Left, multiple, below recurrent laryngeal nerve
Efskind & Liavaag 2
F M
52 35
Neurinoma Neurinoma
No No
Not specified Left recurrent laryngeal nerve (interlobar)
Parellas
M
51
Neurofibrosarcoma (?)
No
Right, cervieothoracic
Gerbode & Marguiles 4
M
24
Neurofibroma
Yes
Left, multiple, vagus and recur rent laryngeal nerve
Gilbertsen & Lillehei 5
M
40
Neurofibroma
No
Bilateral, above and below recur rent laryngeal nerve
Tuttle et al.«
M
30
Neurofibroma
No
Left, below recurrent laryngeal nerve
Penido et al. 7
M P F M
6 39 56 30
Neurofibroma Schwannoma Schwannoma Schwannoma
Yes No No No
Left, 1nultiple, mid-portion Left 1 One above, two Right below recurrent Right. laryngeal nerve
Davis & Browns
F
55
Neurofibroma
No
Left, below recurrent laryngeal nerve
Pampari et al. 9
F
67
Neurofibroma
Yes
Right, below recurrent laryngeal nerve
Carey et al. 1 0
F
Left, recurrent laryngeal nerve
AUTHORS
Blades & Dugan
1
Oberman & Abell 1 1 Ecker et al.12
Gayola et al.
45 ? ?
Schwannoma
No
Neurofibroma Neurofibroma
? ?
SIDE AND LOCATION
M
35
Neurilemmoma
No
M F
47 30
Neurofibroma Neurofibroma
Yes Yes
Left, from apex to hilum, involv. recurrent laryngeal nerve Right, vagus above carina Left, vagus below aortic arch; also tumor of fourth inter costal nerve
M
35
Neurofibroma
No
Right, below recurrent laryngeal nerv e
416
GAYOLA, J A N 1 8 ,
WEIL
J. Thoracic and Cardiovas. Surg.
a neurofibroma with neurofibromatosis. The authors state that one of the tumors was located above, two others below the recurrent laryngeal nerve, and one at the level of the arch of the aorta. They do, however, not state whether or not the recurrent laryngeal nerves were sacrificed in these cases. Two of these cases are included in Carey's series.10 In another case reported by Parella 3 in 1950, a cervicothoracic tumor of the left vagus nerve was partially removed by a combined cervical and thoracic approach as the multinodular growth was found to extend into the mediastinum. This tumor was classified as a neurofibrosarcoma with hemangioma. We wonder, however, if it might not have been benign since an inquiry at the respective hospital revealed that the patient was alive and well 6 years after the operation. This would have been the only malignant intrathoracic tumor of the vagus that we were able to find in the literature. Two malignant vagus sheath tumors reported by Furrer and Fox 13 and Penido 7 were located in the neck and did not extend into the chest. Stout 14 in 1935 reviewed 194 cases of tumors of the peripheral nerves and added 50 new cases. He found only one instance of malignancy and suggested that therapy should be surgical removal, with preservation of the fibers of the larger nerves, if possible, by dissecting out the tumor. No tumors originating from the intrathoracic portion of the vagus are listed in his series, but the observation is made which is also confirmed by other authors 15 ' 16 that there is a higher incidence of malignancy in neurogenic tumors associated with von Recklinghausen's disease. In reviewing other series we did not find reports of intrathoracic vagus tumors,16"25 although from its location, at least one of the tumors reported by Tebow and Brown19 might have originated from the vagus nerve. On the whole, neurogenic mediastinal tumors exhibit a paucity of symptoms. Only occasionally, cough, hoarseness, dysphagia have been present due to com pression of adjacent structures. In 1 case, epigastric distress and cramps were said to have disappeared after resection, but there is no clear evidence that the growth provokes abnormal stimuli. In this respect, there have been recent re ports in the literature indicating that pulmonary hvpertrophic osteoarthropathy may be related to abnormal impulses traveling via the afferent vagal fibers.26 No anatomical changes characteristic of osteoarthropathy have been described in any of the patients with vagal sheath tumors, some of which have, no doubt, been present for years. Unilateral resection of the vagus in the upper medias tinum is tolerated without ill effects; the only complication arises from the interruption of the recurrent laryngeal nerve. Preoperatively, they represent the usual differential diagnostic problems of mediastinal tumors. After vascular lesions are ruled out by angiography, the diagnosis is usually made at the time of operation. The postoperative pulmonary complications are, in our opinion, at least as much due to inefficient coughing from a paralyzed cord added to a thoracotomy incision, as to a questionably altered ciliary action, bronchial peristalsis, and mucous secretions from the interruption of the parasympathetie fibers, as suggested by Gilbertsen and Lillehei.5 In the discussion of this case we would like to stress two points. First, that one can recognize the benign nature of the lesion at the time of surgery and, second, that conservatism in resection is justified once the diagnosis of benignity
Vol. 49, No. 3 March, 1965
INTRATHORACIC N E R V E S H E A T H TUMOR
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is established. A diagnosis of benign neurogenic tumor can be made by gross examination and frozen section. In our case, the following features were of help in making this diagnosis. The lesion was definitely recognized as being part of the vagus nerve; there was a distinct capsule; the cross section exhibited shiny, light gray, semitranslueent edematous tissue with scattered blood-filled cystic structures. On frozen section one was impressed by the numerous thick-walled blood vessels within a loose fibrillar stroma and loosely packed cells, absence of dense cellular areas, no areas with definite anaplasia of cellular elements. On frozen section the lesion was interpreted as benign neurogenic tumor, probably neurilemmoma. If Antoni type A tissue with Verocay bodies could have been identified, the benign nature of the lesion would have become even more ap parent. On permanent sections the above features were confirmed; however, one could identify nerve fibers within the substance of the tumor and not only in the capsule, which suggests that the lesion was probably a neurofibroma. Al though these fine points of differentiation between neurilemmoma and neuro fibroma are of importance to the pathologist, they do not appear crucial at time of operation when the decision lies between benignity and malignancy. Had the tumor been malignant, a more extensive resection would have been undertaken and the recurrent laryngeal nerve would have been sacrificed. We feel, however, that the decision to sacrifice or preserve important adjacent, struc tures in these cases should not be based on the mere possibility of malignancy. We disagree with Ecker and his co-workers that sacrifice of the vagus nerve and its branches beyond the limit of the tumor is indicated, particularly in view of their own statement that the prognosis of these lesions is excellent since malignant degeneration is not an important consideration.12 When the tumor is proximal to the recurrent laryngeal nerve, the function of the latter cannot be saved. But whenever the tumor arises distal to the recurrent laryngeal nerve, the latter should be preserved even if it is intimately adherent to the tumor. Other important structures in the chest, to which the tumor may be adherent, should also be preserved. SUMMARY
A case of intrathoracic tumor of the vagus sheath is presented with a review of the literature. The benign nature of the lesion can be established with reason able certainty at the time of operation from gross appearance and frozen sec tion. We, therefore, believe that a conservative resection is indicated, particu larly when an important structure, such as the recurrent laryngeal nerve, can be preserved. One rarely encounters malignant tumors of the peripheral nerves and, particularly, of the vagus nerve. REFERENCES 1. Blades, B., and Dugan, D. .T.: Resection of Left Vagus Nerve for Multiple Intra thoracic Neurofibromaa, J. A. M. A. 123: 409, 1943. 2. Efskind, L., and Liavaag, K.: Intrathoracic Neurogenic Tumors, J . THORACIC STJEG. 20: 13, 1950. 3. Parella, G. S.: Neurofibrosarcoma of the Vagus Nerve, New England J . Med. 242: 324, 1950.
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J. Thoracic and Cardiovas. Surg.
4. Gerbode, F., and Marguiles, G. S.: Neurofibromatosis W i t h Intrathoracic Neurofibromas of Vagus Nerve, J . THORACIC SURG. 2 5 : 429, 1953.
5. Gilbertsen, V. A., and Lillehei, C. W.: Bilateral I n t r a t h o r a c i c Neurofibromas of the Vagus Nerve With a Note on t h e Physiologic Effects of Cervicothoracic Vagectomy in M a n : A Case Report, J . THORACIC SURG. 28: 78, 1954. 6. Tuttle, W. M., Sanai, V., and Harms, H . P . : Intrathoracic Neurofibroma of t h e Vagus N e r v e , J . THORACIC SURG. 31: 632, 1956.
7. Penido, J . B . F . , and others: Tumors of t h e Vagus Nerve, Proc. Staff Meet. Mayo Clin. 32: 239, 1957. 8. Davis, C , J r . , and Brown, G.: Intrathoracic Neurofibroma of t h e Vagus Nerve Associ ated With a Diaphragmatic Hernia, J . THORACIC SURG. 33: 532, 1957. 9. Pampari, D., a n d Lacerenza, C : A Case of Neurofibroma of t h e Intrathoracic Vagus Nerve in a Woman With Eecklinghausen's Disease, Surgery 45: 470, 1959. 10. Carey, L . S., Ellis, F . H., J r . , Good, C. A., and Woolner, L. B . : Neurogenic Tumors of the Mediastinum: A Clinicopathologic Study, Am. J . Eoentgenol. 84: 189, 1960. 11. Oberman, H. A., and Abell, M. E . : Neurogenous Neoplasms of the Mediastinum, Cancer 13: 882, 1960. 12. Eeker, E . E., Timmes, J . J., and Miscall, L . : Neurogenic Tumors of t h e Intrathoracic Vagus Nerve, Arch. Surg. 86: 222, 1963. 13. Furrer, E . D., and Fox, I . E . : Perineural Fibrosarcoma of t h e Left Vagus Sheath, West. J . Surg. 48: 584, 1940. 14. Stout, A. P., a n d Carson, W . : The Peripheral Manifestations of. t h e Specific Nerve Sheath Tumor (Neurilemmoma), Am. J . Cancer 24: 751, 1935. 15. Hosoi, K . : Multiple Neurofibromatosis (von Eecklinghausen's Disease) With Special Eeference to Malignant Transformation, Arch. Surg. 22: 258, 1931. 16. Ackerman, L . V., a n d Taylor, F . H . : Neurogenous Tumors Within t h e Thorax: A Clinicopathological Evaluation of 48 Cases, Cancer 4: 669, 1951. 17. Harrington, S. W . : Surgical Treatment in 14 Cases of Mediastinal or Intrathoracic P e r i n e u r a l Fibroblastoma, J . THORACIC SURG. 3 : 590, 1934.
18. Kent, E . M., Blades, B., Valle, A. E., a n d Graham, E . A.: Intrathoracic Neurogenic Tumors, J . THORACIC SURG. 13: 116, 1944.
19. Tebow, L. E., and Brown, E . B . : Neurogenic Tumors of t h e Anterior and Middle Mediastinum, Am. Surgeon 19: 491, 1953. 20. Even, E., and others: Les schwannomes mediastino-pleuraux malins et diffus, J . fran§. med. et chir. thorac. 12: 450, 1958. 21. Urso, L., and others: I ganglioneuromi del mediastino, Ann. I t a l . chir. 35: 353, 1958. 22. Bergmann, F . : L e s neurinomes; propos cliniques, Acta chir. Belg. 58: 215, 1959. 23. Soliani, F . : Neurinomi primitivi intra-polmonari, Policlin. 6 6 : 51, 1959. 24. Bucolossi, P., and others: I tumori neurogenici del mediastino, Tumori (Milano) 4 5 : 113, 1959. 25. Daniel, E . A., J r . , and others: Mediastinal Tumors, Ann. Surg. 151: 783, 1960. 26. Holling, H . E., Brodey, E . S., and Boland, H . C : Pulmonary Hypertrophic Osteoarthropathy, Lancet 2 : 1269, 1961.