A Schwannoma of the Parotid Gland Report of a Case By E. HELIDONIS, G. DOKIANAKIS and P. PANTAZOPOULOS PROFESSOR I. FRIEDMANN)
(with histopathological report by
THE parotid gland is the site of development of benign and malignant tumours, which frequently present a significant challenge to the physician due either to their nature or to their extension to the parapharyngeal space, which is closely related anatomically and pathologically to the parotid gland. Of the benign tumours the most common appear to be the 'mixed' tumours in contrast with other connective tissue neoplasms such as fibromas, neurofibromas, and, especially, schwannomas which are rare (Work and Gates, 1969). Case report . A 44-year-old male was admitted to our clinic with a right parotid mass, which appeared 3 months prior to his admission, and which had been growing fast since then. He complained of no other symptoms. Otolaryngologic and general physical examination were completely normal. The mass was movable, hard, not adherent to the skin, painless; it measured 5 x 6 cm, was localized in front of the auricle, and extended from the zygoma down to the angle of the mandible (Fig. 1). A sialogram was done, and there was no visualization of the parotid ducts in one area (Fig. 2). A chest X-ray and other laboratory tests were within normal limits. The patient was operated upon. A typical parotidectomy incision was made. After identifying the facial nerve and its branches the superficial lobe of the parotid was removed, and multiple cystic masses of different size were identified in the substance of the deep lobe. Some of them extended towards the parapharyngeal space. In order to remove the cysts the two main branches of the facial nerve were carefully spread apart in a V manner, and the deep lobe of the parotid gland and the cysts were removed (Fig, 3) with considerable difficulty. There appeared to be no relationship of the cystic masses to the facial nerve. After they had been removed they were opened. Some of them were filled with a clear fluid and some of them contained a yellowish soft tissue. Recovery was uneventful except for a slight temporary weakness of the facial nerve, which subsided within a few days. The patient left the hospital in good condition, and he has been free of disease for one year following surgery. Histopathology (report by Professor I. Friedmann) Microscopy shows a varied pattern: there arc solid areas composed of spindleshaped cells surrounding small blood vessels (Fig. 4a). These Antoni-A type areas alternate with cystic and Antoni-B type areas (Fig. 4b) composed of cystic spaces of various sizes and lined by flat cells surrounded by clear foamy cells. 833
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FIG. 1 Swelling of the right parotid area.
There is little or no palisading of nuclei, which show some irregularity of size. There are scattered cells with bizarre nuclei and some seem to contain two or three nuclei (Fig. 4c). No mitoses seen. Some of the blood vessels show hyaline degeneration and some of the cysts contain mucoid or hyalinized material. The tumour is well encapsulated and there is no evidence of malignancy. Diagnosis: Schwannoma of the parotid gland. Discussion Connective tissue and neurogenic tumours of salivary glands are rare. Haemangiomas are the only common tumours, and they usually occur in young children, but neural tumours such as neurofibromas and schwannomas are the most frequently encountered benign neurogenic neoplasms, and they almost always involve the parotid gland. These tumours are also rare, as appears from the review of the literature. Castro et al. (1972), found two plexiform neurofibromas and one neurilemmoma in a review of the literature, and Krolls et al. (1972) collected seven such tumours. Usually, neural tumours develop on the facial nerve, or on its branches as they course through the parotid gland. They are usually ovoid or cystic in shape, and show the histological pattern of schwannomas rather than that of neurofibromas (Thackray and Lucas, 1974). Howard et al. (1950) believed that these tumours probably appear in childhood, grow slowly, and may not reach sufficient size to become noticeable until adult life. By the time they are removed, they frequently show degenerative changes with cysts and golden areas of lipid-filled
CLINICAL RECORDS
835
FIG. 2 Parotid sialogram. There is poor visualization of the parotid ducts.
foam cells. This natural history of the disease occurred in our own case in which the patient was unaware of the tumour until he reached the age of 44. Apparently, this tumour originated in another nerve, since it seemed to have no relationship to the facial nerve. The treatment of choice is surgery, which may prove to be extremely tedious due to the multiplicity of cysts and their vicinity to the facial nerve and its branches. An accurate clinical diagnosis cannot be made preoperatively unless there are other associated neural lesions, such as cafe-au-lait spots, which are indicative of von Recklinghausen's disease. Schwannomas grow slowly and practically never become malignant. They do not recur when excised completely. Summary
An unusual case of multiple schwannomas of the parotid gland in a 44-yearold male is presented, and the natural history of the disease is discussed. Neural
FIG. 3 Multiple cystic masses removed from the right parotid gland.
FIG. 4 Histopathology: (a) Vascular spindle-ccll area, showing some tendency to palisading. (b) Cystie structures in foamy Antoni-B-type part of the Schwannoma. (c) Similar area to (a), showing pleomorphic and multiple nuclei in some cells.
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tumours of the salivary glands are rare, and the treatment of choice is surgery. Recurrence seems to be unusual unless the excision is incomplete. REFERENCES CASTRO, E. F., HUVOS, A. G., STRONG, E. W., and FOOTE, F. W. (1972) Cancer, 29,312, HOWARD, J. M., RAWSON, A. J., KOOP, C. E., HORN, R. C , and ROYSTER, H. P. (1950) Surgery,
Gynecology and Obstetrics, 90, 307. KROLLS, S. O,, TRODAHE, J. N., and BOYER, R. C, (1972) Cancer, 30, 459.
THACKRAY, A. C , and LUCAS, R. B. (1974) Tumoursofthe Major Salivary Glands. Published by the AFIP, Washington, D.C., p. 119. WORK, R. W., and GATES, A. G. (1969) Otolaryngotogic Clinics of North America, p. 497, Department of Otolaryngology, School of Medicine, University of Athens, Greece. Hippokration General Hospital, Dir. Prof. P. Pantazopoulos.
(with histopathological report by
THE parotid gland is the site of development of benign and malignant tumours, which frequently present a significant challenge to the physician due either to their nature or to their extension to the parapharyngeal space, which is closely related anatomically and pathologically to the parotid gland. Of the benign tumours the most common appear to be the 'mixed' tumours in contrast with other connective tissue neoplasms such as fibromas, neurofibromas, and, especially, schwannomas which are rare (Work and Gates, 1969). Case report . A 44-year-old male was admitted to our clinic with a right parotid mass, which appeared 3 months prior to his admission, and which had been growing fast since then. He complained of no other symptoms. Otolaryngologic and general physical examination were completely normal. The mass was movable, hard, not adherent to the skin, painless; it measured 5 x 6 cm, was localized in front of the auricle, and extended from the zygoma down to the angle of the mandible (Fig. 1). A sialogram was done, and there was no visualization of the parotid ducts in one area (Fig. 2). A chest X-ray and other laboratory tests were within normal limits. The patient was operated upon. A typical parotidectomy incision was made. After identifying the facial nerve and its branches the superficial lobe of the parotid was removed, and multiple cystic masses of different size were identified in the substance of the deep lobe. Some of them extended towards the parapharyngeal space. In order to remove the cysts the two main branches of the facial nerve were carefully spread apart in a V manner, and the deep lobe of the parotid gland and the cysts were removed (Fig, 3) with considerable difficulty. There appeared to be no relationship of the cystic masses to the facial nerve. After they had been removed they were opened. Some of them were filled with a clear fluid and some of them contained a yellowish soft tissue. Recovery was uneventful except for a slight temporary weakness of the facial nerve, which subsided within a few days. The patient left the hospital in good condition, and he has been free of disease for one year following surgery. Histopathology (report by Professor I. Friedmann) Microscopy shows a varied pattern: there arc solid areas composed of spindleshaped cells surrounding small blood vessels (Fig. 4a). These Antoni-A type areas alternate with cystic and Antoni-B type areas (Fig. 4b) composed of cystic spaces of various sizes and lined by flat cells surrounded by clear foamy cells. 833
834
E. HELIDONIS, G. DOKIANAKIS AND P. PANTAZOPOULOS
FIG. 1 Swelling of the right parotid area.
There is little or no palisading of nuclei, which show some irregularity of size. There are scattered cells with bizarre nuclei and some seem to contain two or three nuclei (Fig. 4c). No mitoses seen. Some of the blood vessels show hyaline degeneration and some of the cysts contain mucoid or hyalinized material. The tumour is well encapsulated and there is no evidence of malignancy. Diagnosis: Schwannoma of the parotid gland. Discussion Connective tissue and neurogenic tumours of salivary glands are rare. Haemangiomas are the only common tumours, and they usually occur in young children, but neural tumours such as neurofibromas and schwannomas are the most frequently encountered benign neurogenic neoplasms, and they almost always involve the parotid gland. These tumours are also rare, as appears from the review of the literature. Castro et al. (1972), found two plexiform neurofibromas and one neurilemmoma in a review of the literature, and Krolls et al. (1972) collected seven such tumours. Usually, neural tumours develop on the facial nerve, or on its branches as they course through the parotid gland. They are usually ovoid or cystic in shape, and show the histological pattern of schwannomas rather than that of neurofibromas (Thackray and Lucas, 1974). Howard et al. (1950) believed that these tumours probably appear in childhood, grow slowly, and may not reach sufficient size to become noticeable until adult life. By the time they are removed, they frequently show degenerative changes with cysts and golden areas of lipid-filled
CLINICAL RECORDS
835
FIG. 2 Parotid sialogram. There is poor visualization of the parotid ducts.
foam cells. This natural history of the disease occurred in our own case in which the patient was unaware of the tumour until he reached the age of 44. Apparently, this tumour originated in another nerve, since it seemed to have no relationship to the facial nerve. The treatment of choice is surgery, which may prove to be extremely tedious due to the multiplicity of cysts and their vicinity to the facial nerve and its branches. An accurate clinical diagnosis cannot be made preoperatively unless there are other associated neural lesions, such as cafe-au-lait spots, which are indicative of von Recklinghausen's disease. Schwannomas grow slowly and practically never become malignant. They do not recur when excised completely. Summary
An unusual case of multiple schwannomas of the parotid gland in a 44-yearold male is presented, and the natural history of the disease is discussed. Neural
FIG. 3 Multiple cystic masses removed from the right parotid gland.
FIG. 4 Histopathology: (a) Vascular spindle-ccll area, showing some tendency to palisading. (b) Cystie structures in foamy Antoni-B-type part of the Schwannoma. (c) Similar area to (a), showing pleomorphic and multiple nuclei in some cells.
838
E. HELIDONIS, G. DOKIANAKIS AND P. PANTAZOPOULOS
tumours of the salivary glands are rare, and the treatment of choice is surgery. Recurrence seems to be unusual unless the excision is incomplete. REFERENCES CASTRO, E. F., HUVOS, A. G., STRONG, E. W., and FOOTE, F. W. (1972) Cancer, 29,312, HOWARD, J. M., RAWSON, A. J., KOOP, C. E., HORN, R. C , and ROYSTER, H. P. (1950) Surgery,
Gynecology and Obstetrics, 90, 307. KROLLS, S. O,, TRODAHE, J. N., and BOYER, R. C, (1972) Cancer, 30, 459.
THACKRAY, A. C , and LUCAS, R. B. (1974) Tumoursofthe Major Salivary Glands. Published by the AFIP, Washington, D.C., p. 119. WORK, R. W., and GATES, A. G. (1969) Otolaryngotogic Clinics of North America, p. 497, Department of Otolaryngology, School of Medicine, University of Athens, Greece. Hippokration General Hospital, Dir. Prof. P. Pantazopoulos.
