Facial nerve schwannoma By C. S. ANAND, P. K. KUMRA, T. S. ANAND and
S. K. SINGH (Gwalior, India) Introduction CERTAIN rare neurogenic tumours of the head and neck present as a complex and pleomorphic group. Many aspects of their pathology are disputed and there is no uniform opinion regarding their origin and distinct criteria of malignant transformation (Boyd, 1935; Conley, 1955; Lichtenstein, 1949). Schwannoma is also known by other names such as neurilemmoma or neurinoma. According to the Stout's (1949) classification of neurogenic tumours as modified by Conley (1955) a schwannoma arises from the Schwann cell which is characterized by an oval nucleus which is situated on the inner surface of the sheath of Schwann, an ectodermal structure to be distinguished from the connective tissue of Henle, Maximow and Bloom (1937). It can be benign or malignant in nature, depending on the late or early invasion of nerve fibres, respectively. The rarity of a schwannoma in an extracranial or extraspinal site can be appreciated by the fact that Stout (1935) was able to find only 194 cases reported in the literature prior to 1935, with a further addition of 52 cases. There have been increasing reports of schwannomas of the head and neck during the last few years. Schwannomas can arise from almost any of the cranial nerves, but most commonly the VHIth cranial nerve is involved, when it is better known as an acoustic neuroma. In addition, the spinal nerve roots, the sympathetic chain, the phrenic nerve and the brachial plexus may be the sites of origin for a schwannoma. Kettel (1946) quotes that neurinomata effect principally the sensory or mixed nerves, however, motor nerves are also affected. The common anatomical sites for the origin of a schwannoma are the central and intracranial portions of the cranial nerves and the intraspinal portions of the spinal nerves, but certain rare peripheral sites of these tumours have been reported by various authors, i.e. in the maxillary antrum by Arora et al. (1973), in the larynx by Palva et al. (1975), in the alanasi by Bhargava et al. (1973), inside the nasal cavity by Krishnamoorthy et al. (1974), in the parapharyngeal space by Singh et al. (1974) and in the tonsillar region by Arneaud (1956). Facial nerve schwannoma Facial nerve schwannomas are still rare clinical entities, creating special problems for the otologist, as they often present with vague otological manifestations. Kettel (1963) mentions 48 cases of facial nerve schwannoma reported in the literature. Lavoie et al. (1967) and Shambaugh et al. (1969) have further reported two and four cases respectively to give a total of 54 cases by that date. Sarkar (1959) and Shambaugh et al. (1969) have given excellent bibliographies with illustrations of each case. 1093
C. S. Anand et al. Recently twenty-three cases of schwannoma of the facial nerve were described by Conley and Janecka (1974), fourteen of them arising from the peripheral portion and the remaining nine from the intratemporal course of the facial nerve. Other reports of facial nerve schwannoma were by Guttman and Simon (1951), Bogdasarian (1944), Lundgren (1947) Loeliger (1947) and Kettel (1950). Tremble and Penfield (1936) reported a case of facial nerve schwannoma arising from the region of the geniculate ganglion and greater superficial petrosal nerve. Marcowicz and Shanon (1958) described a very interesting case of a facial nerve schwannoma, resembling the present case report. The initial complaints of the patient were spasmodic contractions of the eyelids, cheek and angle of the mouth, followed by the development of facial asymmetry. A few months later the patient presented to the otorhinolaryngologist as a case of acute otitis media associated with a haemotympanum found on paracentesis. One year later, the patient developed an aural polyp, biopsy of which revealed a schwannoma. Post-aural mastoid exploration showed a soft cellular mass filling the antrum, aditus and middle ear, without invading the dural plate, lateral sinus or labyrinth. Pathology Macroscopically a schwannoma is a solid, soft—to firm, encapsulated tumour, ovoid or round in shape and white, grey or reddish brown in colour, found in the vicinity of the anatomical course of a nerve. The cut surface shows cystic areas filled with straw-coloured fluid and haemorrhagic areas. Microscopically it shows a thin capsule made of spindle cells, compactly arranged in whorls and two types of tissues, i.e. Antoni type 'A' and Antoni type 'B' tissues, as described by Antoni (1920).
FIG.
1.
Showing elongated nuclei arranged in streaming fashion in a fibriallary stroma. (Haematoxylin—eosin X450.) IO94
Clinical records
FIG. 2. Showing Antoni 'B' areas of Schwannoma. (Haematoxylin—eosin X450.)
FIG. 3. Showing Antoni 'A' areas of Schwannoma. (Haematoxylin—eosin X450.)
Antoni type 'A' areas are present in the centre of the growth and consist of long slender fibres forming fibrillary stroma with branched ends passing between cells, the nuclei of which are elongated without blunt ends. These are arranged in parallel fashion showing marked streaming and palisade pattern (Figs. 1 and 3). Antoni type 'B' tissue is usually seen in the peripheral areas and reveals loose textured material with less regularly arranged cells but with considerable diminution of collagen and many microcysts (Fig. 2). 1095
C. S. Anand et al. Clinical features Facial nerve schwannomas occur in all age groups and both sexes, but more commonly during the third and fourth decades of life (Conley and Janecka, 1974). Manifestations vary according to the part of the facial nerve involved by the growth. An intracranial facial nerve schwannoma may be primary or secondary to an acoustic neuroma. The signs and symptoms are of raised intracranial pressure, facial paralysis and marked retrocochlear deafness. Schwannoma of the horizontal part of the facial nerve causes a conductive deafness due to invasion of the middle ear, with labyrinthine manifestations, i.e. giddiness and vomiting and external meatus invasion after erosion of the tympanic membrane. Facial paralysis occurs late. Schwannoma of the vertical part of the facial nerve presents with early facial palsy, which may be the only symptom for many years. The usual complaint is of persistent pain behind the ear and in the facial region. Early erosion of the external auditory meatus through the posterior meatal wall with or without, tympanic membrane involvement is also seen. These features are similar to those of the case reported in the present article. Peripheral facial nerve schwannomas present as painless lumps with facial paresis (Conley and Janecka, 1974). Diagnosis Pre-operative diagnosis is seldom made correctly on account of the rarity of a facial nerve schwannoma, although those arising from the peripheral portion can be given a provisional diagnosis, if presenting as a soft painless lump in the vicinity of the nerve trunk or its branches. A final diagnosis is made only after an excisional biopsy. Regarding intratemporal facial nerve schwannoma radiography of the mastoids and polytomography are of help in finding the exact site and extent of the growth. Management Like other benign neoplasms, total surgical excision after careful dissection is the treatment of choice followed by nerve grafting if feasible. The return of function depends upon the duration of the facial palsy and involvement of the nerve fibres by tumour tissue. The surgical approach for intratemporal neoplasms is postaural but an endaural approach can be practised for schwannomas involving the horizontal part of the facial nerve. Prognosis The prognosis is good as most of these tumours belong to the benign variety. Case report The patient, K.D., aged 56 years male, a farmer by occupation, resident of a rural area in Uttar Pradesh, was admitted to the Male E.N.T. Ward of J.A. Group of Hospitals, Gwalior, complaining of pain and a purulent discharge from the left ear for 15 days. The patient gave a history of a left facial palsy 1096
Clinical records of 14 years' duration which had developed within 25 days after an insidious onset. He used to have recurrent attacks of pain and discharge from the left ear during the 14-year period, but the facial paralysis remained unchanged. The pain was deep-seated in the postaural region. The patient also complained of gradual diminution of hearing during the 14-year period. He had no labyrinthine symptoms such as giddiness, vertigo or vomiting or cachectic symptoms such as loss of appetite, weakness or loss of weight. On physical examination the patient was found to be anaemic, frail and poorly nourished, and he had a complete left facial paralysis. Otoscopic examination revealed signs of a left otitis externa, a friable brownish swelling on the posterior wall of the deep part of the left external auditory meatus, a postero-superior perforation occupying the margin of the left tympanic membrane, and a foetid scanty mucopurulent discharge. The tuning fork tests showed a negative Rinne in the left ear, a positive Rinne in the right ear; Weber's test lateralized to the left ear, and there was a slight reduction in the absolute bone conduction on both sides. An audiogram revealed a moderate mixed deafness in the left ear and a mild sensorineural deafness in the right ear. Caloric tests were found to be within normal limits. No other significant abnormality was detected on examination of the ears, nose, throat, nasopharynx and larynx. Systemic examination displayed no positive finding except a total left intranuclear facial palsy with loss of taste in the left anterior two-thirds cf the tongue. Haematological investigations showed a total leucocyte count of 12,400 per cubic millimeter, 48 per cent of which were polymorphs, 50 per cent lymphocytes and 2 per cent eosinophils. The haemoglobin was 68 per cent. The erythrocyte sedimentation rate was 45 mm at the end of the first hour. Routine urine analysis was normal. X-ray showed the left mastoid to have uniform sclerosis, while the right mastoid was cellular. Poly tomography was not done. A provisional diagnosis was made of a left chronic suppurative otitis media (attico-antral type) with a chronic mastoiditis and with secondary otitis externa. The facial paralysis was assigned to some other non-otological cause. The patient was given systemic antibiotics and local ear toilet. A postaural modified radical mastoidectomy was then done as for a routine case of atticoantral disease with mastoiditis. The mastoid antrum, however, was found to be filled with a large amount of soft cellular tissue, reddish brown in colour, exterding to the aditus ad antrum and middle ear cavity. This soft tissue mass had eroded the posterior meatal wall to reach the external auditory meatus. The bony capsule of the labyrinth, the tegmen area and the sinus plate were intact. Biopsy report after radical excision showed the histological picture of a schwannoma. The final diagnosis of this otological and neurological curiosity was a benign schwannoma of the vertical part of the facial nerve in the Fallopian canal as it had invaded anteriorly into the posterior meatal wall and posteriorly into the mastoid antrum. The dormant nature and extremely slowgrowing tendency of the tumour indicated its benign nature. 1097
C. S. Anand et al. Conclusion
Among the neoplasms of the peripheral nervous system, schwannoma rarely occur in extracranial and extra-spinal sites. Facial nerve schwannomas are uncommon and less than eighty cases have been reported in the literature available. This is the first case of facial nerve schwannoma recorded during the last 12 years in the Department of Otorhinolaryngology, J.A. Group of Hospitals, Gwalior, and no other report from India of a facial nerve schwannoma was found in the literature. When considering the differential diagnosis of a case of facial paralysis, paresis or idiopathic involuntary movements of the facial muscles, with or without vague otological manifestations schwannoma cf the facial nerve must be considered as a rare possibility. The clinical features of the present case are those of a schwannoma of the vertical part of the facial nerve with early facial palsy, erosion of the external auditory meatus and vague post-aural pain for many years. Summary
The present article gives a brief and complete account of the incidence, pathology, clinical features, diagnosis, management and prognosis of the schwannoma with special reference to facial nerve schwannomas. A case report of a rare schwannoma of the vertical part of the facial nerve found on biopsy of tissue during a postaural modified radical mastoidectomy is included. Acknowledgement
We wish to thank the Superintendent, J.A. Group of Hospitals, Gwalior, for allowing us to publish this rare and interesting case report. REFERENCES ANTONI, N. R. E. (1920) Ueber Ruckenmarkstumoren and Neurofibrome, Munchen. ARNEAUD, J. D. (1956) Journal of Laryngology and Otology, 72, 40. ARORA, M. M. L., BANERJEE, A. K., and BHATTACHARYA, T. K. (1973) Journal of
Laryngology and Otology, 87, 405. BHARGAVA, K. B., GADRE, K. C , and MUNDADA, P. S. (1973) Journal of Laryngology
and Otology, 87, 822. BOGDASARIAN, R. M. (1944) Archives of Otolaryngology {Chicago), 40, 291. BOYD, W. (1935) A Textbook of Pathology, Philadelphia, p. 879. CONLEY, J. J. (1955) Archives of Otolaryngology (Chicago), 61, 167. CONLEY, J., and JANECKA, I. (1974) Laryngoscope, 84, 958.
GUTTMAN, M. R., and SIMON, M. U. (1951) Archives of Otolaryngology (Chicago), 54, 162.
KETTEL, K. (1946) Archives of Otolaryngology, 44, 253. KETTEL, K. (1950) Archives of Otolaryngology, 52, 778. KETTEL, K. (1963) Archives of Otolaryngology, 11, 327. KRISHNAMOORTHY, K., PRASAD, G. S. V., RAKSHIT, B. K., and REDDY, C. R. S. M.
(1974) Indian Journal of Laryngology and Otology, 36, 6. LAVOIE, R., GAUTHIER, G. T., and LAVOIE, J. C. (1967) Archives of Otolaryngology,
86, 374LICHTENSTEIN, B. W. (1949) A Textbook of Neuropathology, Philadelphia, 187. LOELIGER, H. T. (1947) Ada Otolaryngology (Stockh.), 52, 778. 1098
Clinical records LUNDGREN, N. (1947) Ada Otolaryngology (Stockh.), 35, 535. MARCOWTCZ, H., and SHANON, E. (1958) Journal of Laryngology and Otology, 72, 137. MAXIMOW, A. A., and BLOOM, W. (1937) A Textbook of Histology, Philadelphia, 187. PALVA, T., JOKINEN, K., and KARJA, J. (1975) Journal of Laryngology and Otology,
89, 203. SARKAR, S. (1959) Journal of Laryngology and Otology, 73, 129. SHAMBAUGH, G. E., ARENBERG, I. K., and VALVASSORI, G. E. (1969) Archives of
Otolaryngology, 90, 742. SINGH,
S. R.,
NAITHANI,
Y. P., and
SINGH,
A. P. (1974) Indian Journal of Laryn-
gology and Otology, 26, 43. STOUT, A. P. (1935) American Journal of Cancer, 24, 751.
A. P. (1949) 'Tumours of Peripheral nervous system', Atlas of Tumour Pathology, Section II, Fascicle 6. Armed Forces Institute of Pathology. TREMBLE, G. E., and PENFIELD, W. (1936) Archives of Otolaryngology, 23, 573. STOUT,
Dr. S. K. Singh, c/o Shri Ramjidas Mabor Advocate, Madhoganj, Kampoo Road, Gwalior 474001 (M.P.), India.
1099
S. K. SINGH (Gwalior, India) Introduction CERTAIN rare neurogenic tumours of the head and neck present as a complex and pleomorphic group. Many aspects of their pathology are disputed and there is no uniform opinion regarding their origin and distinct criteria of malignant transformation (Boyd, 1935; Conley, 1955; Lichtenstein, 1949). Schwannoma is also known by other names such as neurilemmoma or neurinoma. According to the Stout's (1949) classification of neurogenic tumours as modified by Conley (1955) a schwannoma arises from the Schwann cell which is characterized by an oval nucleus which is situated on the inner surface of the sheath of Schwann, an ectodermal structure to be distinguished from the connective tissue of Henle, Maximow and Bloom (1937). It can be benign or malignant in nature, depending on the late or early invasion of nerve fibres, respectively. The rarity of a schwannoma in an extracranial or extraspinal site can be appreciated by the fact that Stout (1935) was able to find only 194 cases reported in the literature prior to 1935, with a further addition of 52 cases. There have been increasing reports of schwannomas of the head and neck during the last few years. Schwannomas can arise from almost any of the cranial nerves, but most commonly the VHIth cranial nerve is involved, when it is better known as an acoustic neuroma. In addition, the spinal nerve roots, the sympathetic chain, the phrenic nerve and the brachial plexus may be the sites of origin for a schwannoma. Kettel (1946) quotes that neurinomata effect principally the sensory or mixed nerves, however, motor nerves are also affected. The common anatomical sites for the origin of a schwannoma are the central and intracranial portions of the cranial nerves and the intraspinal portions of the spinal nerves, but certain rare peripheral sites of these tumours have been reported by various authors, i.e. in the maxillary antrum by Arora et al. (1973), in the larynx by Palva et al. (1975), in the alanasi by Bhargava et al. (1973), inside the nasal cavity by Krishnamoorthy et al. (1974), in the parapharyngeal space by Singh et al. (1974) and in the tonsillar region by Arneaud (1956). Facial nerve schwannoma Facial nerve schwannomas are still rare clinical entities, creating special problems for the otologist, as they often present with vague otological manifestations. Kettel (1963) mentions 48 cases of facial nerve schwannoma reported in the literature. Lavoie et al. (1967) and Shambaugh et al. (1969) have further reported two and four cases respectively to give a total of 54 cases by that date. Sarkar (1959) and Shambaugh et al. (1969) have given excellent bibliographies with illustrations of each case. 1093
C. S. Anand et al. Recently twenty-three cases of schwannoma of the facial nerve were described by Conley and Janecka (1974), fourteen of them arising from the peripheral portion and the remaining nine from the intratemporal course of the facial nerve. Other reports of facial nerve schwannoma were by Guttman and Simon (1951), Bogdasarian (1944), Lundgren (1947) Loeliger (1947) and Kettel (1950). Tremble and Penfield (1936) reported a case of facial nerve schwannoma arising from the region of the geniculate ganglion and greater superficial petrosal nerve. Marcowicz and Shanon (1958) described a very interesting case of a facial nerve schwannoma, resembling the present case report. The initial complaints of the patient were spasmodic contractions of the eyelids, cheek and angle of the mouth, followed by the development of facial asymmetry. A few months later the patient presented to the otorhinolaryngologist as a case of acute otitis media associated with a haemotympanum found on paracentesis. One year later, the patient developed an aural polyp, biopsy of which revealed a schwannoma. Post-aural mastoid exploration showed a soft cellular mass filling the antrum, aditus and middle ear, without invading the dural plate, lateral sinus or labyrinth. Pathology Macroscopically a schwannoma is a solid, soft—to firm, encapsulated tumour, ovoid or round in shape and white, grey or reddish brown in colour, found in the vicinity of the anatomical course of a nerve. The cut surface shows cystic areas filled with straw-coloured fluid and haemorrhagic areas. Microscopically it shows a thin capsule made of spindle cells, compactly arranged in whorls and two types of tissues, i.e. Antoni type 'A' and Antoni type 'B' tissues, as described by Antoni (1920).
FIG.
1.
Showing elongated nuclei arranged in streaming fashion in a fibriallary stroma. (Haematoxylin—eosin X450.) IO94
Clinical records
FIG. 2. Showing Antoni 'B' areas of Schwannoma. (Haematoxylin—eosin X450.)
FIG. 3. Showing Antoni 'A' areas of Schwannoma. (Haematoxylin—eosin X450.)
Antoni type 'A' areas are present in the centre of the growth and consist of long slender fibres forming fibrillary stroma with branched ends passing between cells, the nuclei of which are elongated without blunt ends. These are arranged in parallel fashion showing marked streaming and palisade pattern (Figs. 1 and 3). Antoni type 'B' tissue is usually seen in the peripheral areas and reveals loose textured material with less regularly arranged cells but with considerable diminution of collagen and many microcysts (Fig. 2). 1095
C. S. Anand et al. Clinical features Facial nerve schwannomas occur in all age groups and both sexes, but more commonly during the third and fourth decades of life (Conley and Janecka, 1974). Manifestations vary according to the part of the facial nerve involved by the growth. An intracranial facial nerve schwannoma may be primary or secondary to an acoustic neuroma. The signs and symptoms are of raised intracranial pressure, facial paralysis and marked retrocochlear deafness. Schwannoma of the horizontal part of the facial nerve causes a conductive deafness due to invasion of the middle ear, with labyrinthine manifestations, i.e. giddiness and vomiting and external meatus invasion after erosion of the tympanic membrane. Facial paralysis occurs late. Schwannoma of the vertical part of the facial nerve presents with early facial palsy, which may be the only symptom for many years. The usual complaint is of persistent pain behind the ear and in the facial region. Early erosion of the external auditory meatus through the posterior meatal wall with or without, tympanic membrane involvement is also seen. These features are similar to those of the case reported in the present article. Peripheral facial nerve schwannomas present as painless lumps with facial paresis (Conley and Janecka, 1974). Diagnosis Pre-operative diagnosis is seldom made correctly on account of the rarity of a facial nerve schwannoma, although those arising from the peripheral portion can be given a provisional diagnosis, if presenting as a soft painless lump in the vicinity of the nerve trunk or its branches. A final diagnosis is made only after an excisional biopsy. Regarding intratemporal facial nerve schwannoma radiography of the mastoids and polytomography are of help in finding the exact site and extent of the growth. Management Like other benign neoplasms, total surgical excision after careful dissection is the treatment of choice followed by nerve grafting if feasible. The return of function depends upon the duration of the facial palsy and involvement of the nerve fibres by tumour tissue. The surgical approach for intratemporal neoplasms is postaural but an endaural approach can be practised for schwannomas involving the horizontal part of the facial nerve. Prognosis The prognosis is good as most of these tumours belong to the benign variety. Case report The patient, K.D., aged 56 years male, a farmer by occupation, resident of a rural area in Uttar Pradesh, was admitted to the Male E.N.T. Ward of J.A. Group of Hospitals, Gwalior, complaining of pain and a purulent discharge from the left ear for 15 days. The patient gave a history of a left facial palsy 1096
Clinical records of 14 years' duration which had developed within 25 days after an insidious onset. He used to have recurrent attacks of pain and discharge from the left ear during the 14-year period, but the facial paralysis remained unchanged. The pain was deep-seated in the postaural region. The patient also complained of gradual diminution of hearing during the 14-year period. He had no labyrinthine symptoms such as giddiness, vertigo or vomiting or cachectic symptoms such as loss of appetite, weakness or loss of weight. On physical examination the patient was found to be anaemic, frail and poorly nourished, and he had a complete left facial paralysis. Otoscopic examination revealed signs of a left otitis externa, a friable brownish swelling on the posterior wall of the deep part of the left external auditory meatus, a postero-superior perforation occupying the margin of the left tympanic membrane, and a foetid scanty mucopurulent discharge. The tuning fork tests showed a negative Rinne in the left ear, a positive Rinne in the right ear; Weber's test lateralized to the left ear, and there was a slight reduction in the absolute bone conduction on both sides. An audiogram revealed a moderate mixed deafness in the left ear and a mild sensorineural deafness in the right ear. Caloric tests were found to be within normal limits. No other significant abnormality was detected on examination of the ears, nose, throat, nasopharynx and larynx. Systemic examination displayed no positive finding except a total left intranuclear facial palsy with loss of taste in the left anterior two-thirds cf the tongue. Haematological investigations showed a total leucocyte count of 12,400 per cubic millimeter, 48 per cent of which were polymorphs, 50 per cent lymphocytes and 2 per cent eosinophils. The haemoglobin was 68 per cent. The erythrocyte sedimentation rate was 45 mm at the end of the first hour. Routine urine analysis was normal. X-ray showed the left mastoid to have uniform sclerosis, while the right mastoid was cellular. Poly tomography was not done. A provisional diagnosis was made of a left chronic suppurative otitis media (attico-antral type) with a chronic mastoiditis and with secondary otitis externa. The facial paralysis was assigned to some other non-otological cause. The patient was given systemic antibiotics and local ear toilet. A postaural modified radical mastoidectomy was then done as for a routine case of atticoantral disease with mastoiditis. The mastoid antrum, however, was found to be filled with a large amount of soft cellular tissue, reddish brown in colour, exterding to the aditus ad antrum and middle ear cavity. This soft tissue mass had eroded the posterior meatal wall to reach the external auditory meatus. The bony capsule of the labyrinth, the tegmen area and the sinus plate were intact. Biopsy report after radical excision showed the histological picture of a schwannoma. The final diagnosis of this otological and neurological curiosity was a benign schwannoma of the vertical part of the facial nerve in the Fallopian canal as it had invaded anteriorly into the posterior meatal wall and posteriorly into the mastoid antrum. The dormant nature and extremely slowgrowing tendency of the tumour indicated its benign nature. 1097
C. S. Anand et al. Conclusion
Among the neoplasms of the peripheral nervous system, schwannoma rarely occur in extracranial and extra-spinal sites. Facial nerve schwannomas are uncommon and less than eighty cases have been reported in the literature available. This is the first case of facial nerve schwannoma recorded during the last 12 years in the Department of Otorhinolaryngology, J.A. Group of Hospitals, Gwalior, and no other report from India of a facial nerve schwannoma was found in the literature. When considering the differential diagnosis of a case of facial paralysis, paresis or idiopathic involuntary movements of the facial muscles, with or without vague otological manifestations schwannoma cf the facial nerve must be considered as a rare possibility. The clinical features of the present case are those of a schwannoma of the vertical part of the facial nerve with early facial palsy, erosion of the external auditory meatus and vague post-aural pain for many years. Summary
The present article gives a brief and complete account of the incidence, pathology, clinical features, diagnosis, management and prognosis of the schwannoma with special reference to facial nerve schwannomas. A case report of a rare schwannoma of the vertical part of the facial nerve found on biopsy of tissue during a postaural modified radical mastoidectomy is included. Acknowledgement
We wish to thank the Superintendent, J.A. Group of Hospitals, Gwalior, for allowing us to publish this rare and interesting case report. REFERENCES ANTONI, N. R. E. (1920) Ueber Ruckenmarkstumoren and Neurofibrome, Munchen. ARNEAUD, J. D. (1956) Journal of Laryngology and Otology, 72, 40. ARORA, M. M. L., BANERJEE, A. K., and BHATTACHARYA, T. K. (1973) Journal of
Laryngology and Otology, 87, 405. BHARGAVA, K. B., GADRE, K. C , and MUNDADA, P. S. (1973) Journal of Laryngology
and Otology, 87, 822. BOGDASARIAN, R. M. (1944) Archives of Otolaryngology {Chicago), 40, 291. BOYD, W. (1935) A Textbook of Pathology, Philadelphia, p. 879. CONLEY, J. J. (1955) Archives of Otolaryngology (Chicago), 61, 167. CONLEY, J., and JANECKA, I. (1974) Laryngoscope, 84, 958.
GUTTMAN, M. R., and SIMON, M. U. (1951) Archives of Otolaryngology (Chicago), 54, 162.
KETTEL, K. (1946) Archives of Otolaryngology, 44, 253. KETTEL, K. (1950) Archives of Otolaryngology, 52, 778. KETTEL, K. (1963) Archives of Otolaryngology, 11, 327. KRISHNAMOORTHY, K., PRASAD, G. S. V., RAKSHIT, B. K., and REDDY, C. R. S. M.
(1974) Indian Journal of Laryngology and Otology, 36, 6. LAVOIE, R., GAUTHIER, G. T., and LAVOIE, J. C. (1967) Archives of Otolaryngology,
86, 374LICHTENSTEIN, B. W. (1949) A Textbook of Neuropathology, Philadelphia, 187. LOELIGER, H. T. (1947) Ada Otolaryngology (Stockh.), 52, 778. 1098
Clinical records LUNDGREN, N. (1947) Ada Otolaryngology (Stockh.), 35, 535. MARCOWTCZ, H., and SHANON, E. (1958) Journal of Laryngology and Otology, 72, 137. MAXIMOW, A. A., and BLOOM, W. (1937) A Textbook of Histology, Philadelphia, 187. PALVA, T., JOKINEN, K., and KARJA, J. (1975) Journal of Laryngology and Otology,
89, 203. SARKAR, S. (1959) Journal of Laryngology and Otology, 73, 129. SHAMBAUGH, G. E., ARENBERG, I. K., and VALVASSORI, G. E. (1969) Archives of
Otolaryngology, 90, 742. SINGH,
S. R.,
NAITHANI,
Y. P., and
SINGH,
A. P. (1974) Indian Journal of Laryn-
gology and Otology, 26, 43. STOUT, A. P. (1935) American Journal of Cancer, 24, 751.
A. P. (1949) 'Tumours of Peripheral nervous system', Atlas of Tumour Pathology, Section II, Fascicle 6. Armed Forces Institute of Pathology. TREMBLE, G. E., and PENFIELD, W. (1936) Archives of Otolaryngology, 23, 573. STOUT,
Dr. S. K. Singh, c/o Shri Ramjidas Mabor Advocate, Madhoganj, Kampoo Road, Gwalior 474001 (M.P.), India.
1099
