J Oral Maxillofac Surg 50:1217-1221,1992
Malignant Schwannoma of the Palate: A Case Report and Review of the Literature MARIANNE DCERBO, DDS,* JAMES J. SCIUBBA, DMD, PHD,t W.C. SORDILL, DMD,$ AND DEAN M. DELUKE, DDS§
The malignant schwannoma is an uncommon neoplasm of the head and neck region, and its presentation in the oral cavity is quite rare. Malignant schwannoma of the head and neck region represents approximately 8% to 16% of the total body distribution of this turnor.lA It can either arise independently or result from malignant change in a preexisting neurofibroma. Multiple neurofibromas, characteristic of von Recklinghausen’s disease, will demonstrate malignant change in 8% to 10% of patients. ‘J Malignant degeneration of a benign schwannoma is rare and conceptually controversial; Toriumi et al’ have noted only four adequately documented cases of such a transformation. The discussion of peripheral nerve tumors is complicated by the fact that there is disagreement over the histogenesis of these tumors and a lack of universally accepted terminology. Although there exists some debate6-9 most authors1,3,5~10,”currently believe that the Schwann cell is the precursor of the neurofibroma, schwannoma, and malignant schwannoma. A review of the literature regarding peripheral nerve sheath tumors reveals a multitude of terms for apparently similar lesions. Piatelli et al” found up to 19 terms (Table 1) for the malignant form of the schwannoma; for the sake of clarity, the term malignant schwannoma will be used in this report. Taking into account the previous literature reviews of Eversole et a127and Martinez and Robinson6 there exist a total of 34 documented cases
* Formerly, General Practice Resident, St Glare’s Hospital, Schenectady, NY; currently, Postgraduate in Orthodontics, Columbia University School of Dental and Oral Surgery, New York, NY. t Chairman, Department of Dental Medicine, and Attending Oral Pathologist, Long Island Jewish Medical Center, New Hyde Park, NY. t Formerly, Director of Dental Education, St Clare’s Hospital; currently in private practice, Livingston, NJ. p Chief, Department of Dentistry and Oral Surgery, St Clare’s Hospital, Schenectady, NY. Address correspondence and reprint requests to Dr DeLuke: Department of Dentistry and Oral Surgery, St Clare’s Hospital, 600 McClellan St, Schenectady, NY 12304. 0 1992 American 0278-2391/92/501
Association l-0013$3.00/0
of Oral and Maxillofacial
Surgeons
of intraoral and perioral malignant schwannomas (Table 2); only two of these were on the palate. The following report describes another case that is unusual because of the age of the patient. Report of Case A 13-year-old white girl presented with a chief complaint of a sore in the roof of her mouth. The lesion had been present for 3 months and had slowly increased in size until recently when the patient noticed a more rapid increase in size and discomfort. Her past medical history included asthma, for which she took theophylline. She currently smoked one pack of cigarettes daily and used alcohol occasionally. Examination revealed a solitary ulcerated mass of the left hard palate measuring 1.5 cm in diameter (Fig 1). The lesion was tender and nonindurated, with well-defined, raised borders and central cratering. Radiographs, including panoramic, periapical, and occlusal views, were all normal. There was no dental pathology, and the adjacent teeth were all vital. The complete blood count, SMA-20, and chest radiograph were normal. The VDRL test was nonreactive and the tuberculin skin test was negative. The clinical, radiographic, and laboratory data suggested a benign or malignant tumor of neural or salivary gland origin. Mucoepidermoid carcinoma is the most common malignancy of salivary gland origin occurring in children; lymphoma, which can present as a palatal swelling or ulceration, would also have to be considered. Other diseases that may present as solitary ulcerations on the palate were largely excluded by the relevant history and initial workup (eg, tuberculosis, granulomatous disease, major aphthous ulcer, necrotizing sialometaplasia, syphilis, traumatic ulceration, and neoplasia arising from antrum). Epidermoid carcinoma rarely occurs in children. A punch biopsy of the palatal lesion was reported as fibroma. Wide excisional biopsy was undertaken, and the specimen revealed a highly cellular, spindle-cell lesion with numerous mitoses arising in proximity to nerve bundles (Fig 2); electron micrographs (Fig 3) suggested origin from the Schwann cell. At the time that this patient was initially treated, immunoperoxidase-staining for the neural-crest marker, S100 protein, was unavailable. The wide local excision was followed with a hard palatectomy, and a small residual focus of tumor was found; the margins and bone were free of tumor. An antral obturator was made postoperatively. The patient remained disease-free for 7 years, at which time she was lost to follow-up. She had repeatedly elected not to undergo further surgery for closure of a small residual oral-antral fistula.
1217
1218
MALIGNANT SCHWANNOMA
Table 1. Synonyms for Malignant Peripheral-Nerve Tumors Malignant neurilemoma Malignant neurogenous neoplasm Neurolibrosarcoma Neurogenic sarcoma Neurogenous sarcoma Malignant peripheral glioma Neurogenic fibrosarcoma Nerve sheath sarcoma Malignant nerve tumor Peripheral nerve sarcoma Metapiastic malignant schwannoma Malignant Triton tumor Malignant nerve sheath tumor Fasciculated sarcoma Malignant neurinoma Schwannosarcoma Fibromyosarcoma of the nerve Malignant schwannoma Myxosarcoma of nerve sheath
Discussion Malignant peripheral nerve tumors can mimic a variety of primary and metastatic diseases in their clinical presentation. Malignant schwannoma often produces symptoms of pain and/or paresthesia,6*7*27followed shortly thereafter by the presence of an expanding mass.‘*2*6*7 The lesion may occur anywhere in the oral cavity, but the mandible, lips, and buccal mucosa are the most common sites. If present in soft tissue, the margins are usually indiscrete, and ulceration of the mucosa may occur. Intraosseous tumors of the mandible may present as a widening of the mandibular canal or the mental foramen.12 There appears to be no sex predilection, and the majority of lesions occur in the third to fifth decade of life. The tumor tends to spread along the nerve of origin, and hematogenous spread to the lung may occur27; lymphatic dissemination rarely occurs. As a rule, the malignant schwannoma is an aggressive lesion that, if incompletely excised, tends to show rapid local recurrence with an increased degree of malignancy. 1*2*7,30 A diagnosis of malignant schwannoma using conventional histologic methods alone is difficult to make. This problem is compounded when either small biopsy or curettage specimens are obtained, as with the original punch biopsy in this case. Histologically, the malignant schwannoma is composed of spindle cells with plump, ovoid and vesicular nuclei exhibiting varying degrees of pleomorphism. Cellular, epithelioid, or glandular patterns may be seen. A differential diagnosis would include other spindle-cell tumors that display similar overall organization, including fibrosarcoma, leiomyosarcoma, malignant melanoma, and monophasic synovial sarcoma. Electron microscopy is helpful in
OF THE PALATE
diagnosing tumors of Schwann-cell origin by identifying the characteristic basement membrane of the Schwann cell.2 The more recent development of immunoperoxidase-staining for the neural-crest marker, S- 100 protein, has further aided the correct identification of malignant schwannoma. This marker was first described in glial cells, but has since been demonstrated in numerous cells of neural-crest origin, including the Schwann cell.30 Unfortunately, this marker is not always positive
Table 2. Malignant Schwannomas of the Oral Region: Review of the Literature
Investigator(s) (chronological order)
Patient Age (yr)/Sex
Lewis and Hart’*” Cutler and GrossI
41/M 32/F
Bell I4 Wilson and Walsh I5 DeLarue et al I6 Millard and Busseri7 Wise and Asbury” Cuneo and Rand” Economou et aI*’
65/F 2/F 30/M 42/F 31/M 37/M 56/M 59/M 34/F 20/M 50/M 6/M
Villa and Buwag” DeVore and Waldron 7 Ingram** Hayward*’
23fF
65/M 4.5/F
14/F
Shklar and Meyer24
NA/NA
Blankenship et a125 Hammond and Calderwood26 Das Gupta et al“ Eversole et al” Martinez and Robinson6 Wasserman et alZ8 Upton et al* Piatelli et al’* Gullane et aI2
52/F 58/F
Shirasuna and Kanemitsuz9 Piscioli et a130 Guglielmotti et al” Kameyama9
NA/NA 47/M 28fM 36/M 38/M 18/F 67/F 66/F 42/F 16/F 23/M 18/M 61/F
Follow-up Data
Location Lower lip Infraorbital fissure Mandible Mandible Mandible Maxilla Lip Mandible Lower lip Upper lip Submandibular region Buccal mucosa Buccal mucosa Submandibular region Mandible Mandible
5 Years 6 Months
Mandible Mental foramen NA
IO Months I Year
NA NA 6 Months 4 Months 5 Months 1 Year 5 Years 2 Years 2 Years 3 Years 2 Years 4 Years NA 20
Months
Palate Buccal mucosa
3 Cases not documented 6 Weeks I Week
Cheek Mandible Palate
NA I5 Months 2 Years
Lingual nerve Mandible
21 Months 3.5 Years 3 Years 9 Months 15 Months 2 Years I Year
Tongue
Cheek Zygoma Maxillary sinus Mandible Submandibular gland Gingiva Maxilla
80 Months 2 Years 19 Months
DICERBO ET AL
FIGURE 1. Clinical appearance of the raised, slightly umbilicated, craterform mass.
in malignant schwannoma; Enzinger 33 demonstrated its presence in up to one half of malignant schwannomas studied. Although malignant melanoma has also been shown to be positive for the S- 100 marker, fibrosarcoma, leiomyosarcoma, and sarcomatoid undifferentiated carcinoma do not contain this protein.30 The
1219 presence of S- 100 protein, in combination with a thorough clinical history, and light and electron microscopy will enhance the pathologist’s ability to correctly identify a given tumor as malignant schwannoma. Authors who have studied the problems associated with this identification agree that the following clinicopathologic criteria should be applied5v30734: 1) the presence of von Recklinghausen’s disease, 2) gross or microscopic demonstration of the origin of the neoplasm within the anatomic compartment of a nerve, 3) close association of the origin of the neoplasm in a tumor having the histologic pattern of neurofibroma, 4) presence of a spindle-cell neoplasm arising at the site of a previously excised neurofibroma, 5) specific microscopic characteristics, including extreme pleomorphism, numerous mitoses, necrosis, and hypercellularity. There are varying opinions as to the appropriate modalities of therapy and survival rates associated with malignant peripheral nerve tumors. Performing a wide surgical excision is imperative. Das Gupta and Brasfield demonstrated that radiotherapy as the primary mode of treatment produced poor results. Other reports support the role of postoperative radiation.‘*30 The role of adjunctive chemotherapy is limited, except in occasional cases of metastatic disease. ‘v3’Cur-
FIGURE 2. A, Low-power photomicrogmph showing swirling masses of neoplastic cells separated by areas of fibrous connective tissue (hematoxylin-eosin stain, original magnification X40). B, Mediumpower view showing scattered mitotic figures within a spindle-cell background. Groups of spindle celis form a slightly whorled pattern, and demonstrate pleomorphism and nuclear hyperchromatism (hematoxylin-eosin stain, original magnification X100). C, High-power view showing several mitoses, bundles of parallel, spindle-shaped cells, and a slightly fibrillar background (hematoxylin-eosin stain, original magnification X200).
MALIGNANT SCHWANNOMA
OF THE PALATE
FIGURE 3. Electron micrographs of the lesion showing its characteristic features. A, Parallel spindle cells with basement membrane material (arrows) and dendritic processes (original magnification ~6,400). B, Myelin bodies composed of phospholipid material (arrowheads) are present along with scattered mitochondria (m), rough endoplasmic reticulum (arrow), and focally aggregated basement membrane material on the outer cell border (original magnification x 13,400).
rently, the best prognosis is given to patients with tumors less than 5 cm in diameter not arising from a lesion of von Recklinghausen’s disease, and treated with an aggressive surgical approach followed by postoperative radiotherapy.‘s2 The present report adds to the literature an additional case of intraoral malignant schwannoma; it is one of few reported on the palate and it occurred in a teenager. The initial diagnosis was probably made difficult by a small incisional specimen, a common pitfall in oral pathology. Fortunately, the ultimate surgical therapy was apparently curative, and postoperative radiotherapy was not required. References
3. 4. 5. 6.
7.
8. 9. 10.
1I. I. Toriumi DM, Atiyah RA, Murad T, et al: Extracranial neurogenic tumors ofthe head and neck. Otolaryngol Clin North Am 19: 609, 1986 2. Gullane PJ, Gilbert RW, Van Nostrand ANP, et al: Malignant
12.
schwannoma in the head and neck. J Otolaryngol 14: 17 I. 1985 Ghosh BC, Ghosh L, Huvas AC, et al: Malignant schwannoma: A clinicopathologic study. Cancer 3 I: 184, 1973 Das Gupta TK, Brasfield RD: Solitary malignant schwannoma. Ann Surg 171:419, 1970 Batsakis JG: Tumors of the Head and Neck. Baltimore, MD, Williams & Wilkins, 1974, pp 23 I-249 Martinez MG, Robinson LH: Primary neurogenic sarcomas of the oral region: A report of two cases. Ala J Med Sci 13:32, 1976 DeVom DT, Waldron CA: Malignant peripheral nerve tumors of the oral cavity: Review of the literature and report of a case. Oral Sura 14~56. 1961 Upton LG, Hay&rd JR, Kerr DA: Neurofibrosarcoma of the mandible. J Oral Sure 35:504. 1977 Kameyama Y: Malignant schwannoma of the maxilla in a patient without neurofibromatosis. Histopathology I 1:1205, 1987 Penfield W: Tumors of the sheath of the nervous system. Arch Neural Psycho1 27: 1298, I932 Murray MR, Stout AP, Bradley CF: Schwann cells vetsus fibroblast as the origin of the specific nerve sheath tumor. Am J Path01 16:41, 1940 Piatelli A, Angelone A, Pizzicanneha G, et al: Malignant schwannoma of the tongue: Report of a case and review of the literature. Acta Stomatol Belg 8 I:2 13, I984
1221
GORDON B. WONG
12a.Lewis D, Hart D: Tumors of peripheral nerves. Ann Surg 92: 961, 1930 13. Cutler EC, Gross RE: Neurofibroma and neurosarcoma of the peripheral nerves. Arch Surg 33:733, 1936 14. Bell WE: Neurogenic sarcoma of the mandible: Report of a case. J Am Dent Assoc 23:1351, 1936 15. Wilson S, Walsh JP: Neurogenic fibroma in a young child. North Am Dent J 44:123, 1948 16. DeLarue J, Haguenau M, Fiiez MM, et al: Neurinome malin de nerfdentaire inferiour: Etude anatomo-clinique. Rev Stomatol 5Ck529, 1949 17. Millard P, Busser F: Schwannome due maxillaire superieur d’evolution maligne. Ann Otolaryngol 69:706, 1952 18. Wise RA, Asbury GF: Malignant neurinomas of peripheral nerves. Ann Surg 136:874, 1952 19. Cuneo HM, Rand CW: Tumors of the gas&an ganglion: Tumor of the left gasserian ganglion associated with enlargement of the mandibular nerve: Review of literature and case report. J Neurosurg 9:423, 1952 20. Economou S Jr, Southwick HN, Slaughter DP: Neurofibrosarcomas of cranial nerve origin. Arch Surg 77:27 1, 1958 2 1. Villa VG, Buwag CA: Neurogenic fibrosarcoma in the mandible observed about one month after extraction of a lower third molar. Oral Surg 13:205, 1960 22. Ingram n: Radiology of tumors of the mandible. Clin Radio1 13:47, 1962 23. Hayward JR Trigeminal neurofibrosarcoma: Report of a case. J Oral Surg 21:518, 1963
J Oral Maxillofac
24. Shklar G, Meyer I: Neurogenic tumors of the mouth and jaws. Oral Surg 16:1075, 1963 25. Blankenship BJ, Stout R, Bradley T, et al: Neurofibrosarcoma of the palate associated with neurofibromatosis primary or metastatic. Oral Surg 22: 139, 1966 26. Hammond HL, Calderwood RG: Malignant peripheral nerve tumors of the oral cavity: Review of the literature and report of a case. Oral Smg Oral Med Oral Pathol28:97, 1969 27. Eversole LR, Schwartz DW, Sabes WR: Central and peripheral fibrogenic and neurogenic sarcoma of the oral regions. Oral Surg 36:49, 1973 28. Wasserman BS, Finkleman A, John M, et al: Malignant schwannoma of the lingual nerve: A case report. H Irak Med 32:67, 1977 29. Shimsuna, Kanemitsu: Malignant schwannoma of the mandible. Int J Oral Maxillofac Surg 15:772, 1986 30. Piscioli F, Antolini M, Pusiol T, et al: Malignant schwannoma of the submandibular gland: A case report. ORL J Otorhinolaryngol Relat Spec 48: 156, I986 3 I. Gughelmotti MB, Penar C, Dominguez Fv: Malignant schwannoma of the gingiva. Int J Oral Maxillofac Surg 16:492, 1987 32. Moore BW: A soluble protein characteristic ofthe nervous system. Res Commun Chem Path01 Pharmacol 19:739, 1965 33. Enzinger FM: Classification and diagnosis of peripheral neural tumors. Istocitopatologia 5: 157, 1983 34. Trojanowski JQ, Kleinman GM, Proppe KH: Malignant tumors of nerve sheath origin. Cancer 46: 1202, 1980 35. Das Gupta TK: Tumors of peripheral nerves. Clin Neurosurg 25:574, 1977
Surg
50:1221-1224.1992
Large Odontogenic Myxoma of the Mandible Treated by Sagittal Ramus Osteotomy and Peripheral Ostectomy GORDON B. WONG, MSc, DDS*
The odontogenic myxoma is a relatively rare lesion of the jaws, and is reported to represent 0.04% to 0.6% of total surgical specimens submitted to oral pathology departments.‘,* It represents approximately 3% of all odontogenic tumors.’ The mean age at the time of diagnosis varies from 25 to 35 years, with a distinct predominance in females and a predilection for the mandible.2-5 However, an equal incidence of male and female cases also has been reported,6 as well as an equal
* In private practice, Sault Ste Marie, Ontario, Canada. Address correspondence and reprint requests to Dr Wong: 350 Queen St E, Sault Ste Marie, Ontario, P6A 1Zl Canada. Q 1992 American Association of Oral and Maxillofacial Surgeons 0278-2391/92/501
l-001 4$3.00/O
maxillary and mandibular cases.’ The lesion may have three different radiographic presentations.’ The “honey-comb” or “tennis-racquet” appearance is most common, although unilocular or multilocular “soapbubble” appearances also occur. When the tumor has perforated the cortex with the formation of multiple, radiating spicules, it may have a “sunray” or “sunburst” appearance. ‘2’ The usual clinical presentation is that of an asymptomatic, painless swelling, which may also include displaced teeth and paresthesia.* The odontogenic origin of the tumor has been mainly circumstantial, and is based on the predominant occurrence in tooth-bearing regions of the jaws, histologic similarity to the stellate reticulum of a forming tooth, and clinical behavior resembling that of the ameloblastoma. The presence of odontogenic epithelium in some cases also has led some to support this
Malignant Schwannoma of the Palate: A Case Report and Review of the Literature MARIANNE DCERBO, DDS,* JAMES J. SCIUBBA, DMD, PHD,t W.C. SORDILL, DMD,$ AND DEAN M. DELUKE, DDS§
The malignant schwannoma is an uncommon neoplasm of the head and neck region, and its presentation in the oral cavity is quite rare. Malignant schwannoma of the head and neck region represents approximately 8% to 16% of the total body distribution of this turnor.lA It can either arise independently or result from malignant change in a preexisting neurofibroma. Multiple neurofibromas, characteristic of von Recklinghausen’s disease, will demonstrate malignant change in 8% to 10% of patients. ‘J Malignant degeneration of a benign schwannoma is rare and conceptually controversial; Toriumi et al’ have noted only four adequately documented cases of such a transformation. The discussion of peripheral nerve tumors is complicated by the fact that there is disagreement over the histogenesis of these tumors and a lack of universally accepted terminology. Although there exists some debate6-9 most authors1,3,5~10,”currently believe that the Schwann cell is the precursor of the neurofibroma, schwannoma, and malignant schwannoma. A review of the literature regarding peripheral nerve sheath tumors reveals a multitude of terms for apparently similar lesions. Piatelli et al” found up to 19 terms (Table 1) for the malignant form of the schwannoma; for the sake of clarity, the term malignant schwannoma will be used in this report. Taking into account the previous literature reviews of Eversole et a127and Martinez and Robinson6 there exist a total of 34 documented cases
* Formerly, General Practice Resident, St Glare’s Hospital, Schenectady, NY; currently, Postgraduate in Orthodontics, Columbia University School of Dental and Oral Surgery, New York, NY. t Chairman, Department of Dental Medicine, and Attending Oral Pathologist, Long Island Jewish Medical Center, New Hyde Park, NY. t Formerly, Director of Dental Education, St Clare’s Hospital; currently in private practice, Livingston, NJ. p Chief, Department of Dentistry and Oral Surgery, St Clare’s Hospital, Schenectady, NY. Address correspondence and reprint requests to Dr DeLuke: Department of Dentistry and Oral Surgery, St Clare’s Hospital, 600 McClellan St, Schenectady, NY 12304. 0 1992 American 0278-2391/92/501
Association l-0013$3.00/0
of Oral and Maxillofacial
Surgeons
of intraoral and perioral malignant schwannomas (Table 2); only two of these were on the palate. The following report describes another case that is unusual because of the age of the patient. Report of Case A 13-year-old white girl presented with a chief complaint of a sore in the roof of her mouth. The lesion had been present for 3 months and had slowly increased in size until recently when the patient noticed a more rapid increase in size and discomfort. Her past medical history included asthma, for which she took theophylline. She currently smoked one pack of cigarettes daily and used alcohol occasionally. Examination revealed a solitary ulcerated mass of the left hard palate measuring 1.5 cm in diameter (Fig 1). The lesion was tender and nonindurated, with well-defined, raised borders and central cratering. Radiographs, including panoramic, periapical, and occlusal views, were all normal. There was no dental pathology, and the adjacent teeth were all vital. The complete blood count, SMA-20, and chest radiograph were normal. The VDRL test was nonreactive and the tuberculin skin test was negative. The clinical, radiographic, and laboratory data suggested a benign or malignant tumor of neural or salivary gland origin. Mucoepidermoid carcinoma is the most common malignancy of salivary gland origin occurring in children; lymphoma, which can present as a palatal swelling or ulceration, would also have to be considered. Other diseases that may present as solitary ulcerations on the palate were largely excluded by the relevant history and initial workup (eg, tuberculosis, granulomatous disease, major aphthous ulcer, necrotizing sialometaplasia, syphilis, traumatic ulceration, and neoplasia arising from antrum). Epidermoid carcinoma rarely occurs in children. A punch biopsy of the palatal lesion was reported as fibroma. Wide excisional biopsy was undertaken, and the specimen revealed a highly cellular, spindle-cell lesion with numerous mitoses arising in proximity to nerve bundles (Fig 2); electron micrographs (Fig 3) suggested origin from the Schwann cell. At the time that this patient was initially treated, immunoperoxidase-staining for the neural-crest marker, S100 protein, was unavailable. The wide local excision was followed with a hard palatectomy, and a small residual focus of tumor was found; the margins and bone were free of tumor. An antral obturator was made postoperatively. The patient remained disease-free for 7 years, at which time she was lost to follow-up. She had repeatedly elected not to undergo further surgery for closure of a small residual oral-antral fistula.
1217
1218
MALIGNANT SCHWANNOMA
Table 1. Synonyms for Malignant Peripheral-Nerve Tumors Malignant neurilemoma Malignant neurogenous neoplasm Neurolibrosarcoma Neurogenic sarcoma Neurogenous sarcoma Malignant peripheral glioma Neurogenic fibrosarcoma Nerve sheath sarcoma Malignant nerve tumor Peripheral nerve sarcoma Metapiastic malignant schwannoma Malignant Triton tumor Malignant nerve sheath tumor Fasciculated sarcoma Malignant neurinoma Schwannosarcoma Fibromyosarcoma of the nerve Malignant schwannoma Myxosarcoma of nerve sheath
Discussion Malignant peripheral nerve tumors can mimic a variety of primary and metastatic diseases in their clinical presentation. Malignant schwannoma often produces symptoms of pain and/or paresthesia,6*7*27followed shortly thereafter by the presence of an expanding mass.‘*2*6*7 The lesion may occur anywhere in the oral cavity, but the mandible, lips, and buccal mucosa are the most common sites. If present in soft tissue, the margins are usually indiscrete, and ulceration of the mucosa may occur. Intraosseous tumors of the mandible may present as a widening of the mandibular canal or the mental foramen.12 There appears to be no sex predilection, and the majority of lesions occur in the third to fifth decade of life. The tumor tends to spread along the nerve of origin, and hematogenous spread to the lung may occur27; lymphatic dissemination rarely occurs. As a rule, the malignant schwannoma is an aggressive lesion that, if incompletely excised, tends to show rapid local recurrence with an increased degree of malignancy. 1*2*7,30 A diagnosis of malignant schwannoma using conventional histologic methods alone is difficult to make. This problem is compounded when either small biopsy or curettage specimens are obtained, as with the original punch biopsy in this case. Histologically, the malignant schwannoma is composed of spindle cells with plump, ovoid and vesicular nuclei exhibiting varying degrees of pleomorphism. Cellular, epithelioid, or glandular patterns may be seen. A differential diagnosis would include other spindle-cell tumors that display similar overall organization, including fibrosarcoma, leiomyosarcoma, malignant melanoma, and monophasic synovial sarcoma. Electron microscopy is helpful in
OF THE PALATE
diagnosing tumors of Schwann-cell origin by identifying the characteristic basement membrane of the Schwann cell.2 The more recent development of immunoperoxidase-staining for the neural-crest marker, S- 100 protein, has further aided the correct identification of malignant schwannoma. This marker was first described in glial cells, but has since been demonstrated in numerous cells of neural-crest origin, including the Schwann cell.30 Unfortunately, this marker is not always positive
Table 2. Malignant Schwannomas of the Oral Region: Review of the Literature
Investigator(s) (chronological order)
Patient Age (yr)/Sex
Lewis and Hart’*” Cutler and GrossI
41/M 32/F
Bell I4 Wilson and Walsh I5 DeLarue et al I6 Millard and Busseri7 Wise and Asbury” Cuneo and Rand” Economou et aI*’
65/F 2/F 30/M 42/F 31/M 37/M 56/M 59/M 34/F 20/M 50/M 6/M
Villa and Buwag” DeVore and Waldron 7 Ingram** Hayward*’
23fF
65/M 4.5/F
14/F
Shklar and Meyer24
NA/NA
Blankenship et a125 Hammond and Calderwood26 Das Gupta et al“ Eversole et al” Martinez and Robinson6 Wasserman et alZ8 Upton et al* Piatelli et al’* Gullane et aI2
52/F 58/F
Shirasuna and Kanemitsuz9 Piscioli et a130 Guglielmotti et al” Kameyama9
NA/NA 47/M 28fM 36/M 38/M 18/F 67/F 66/F 42/F 16/F 23/M 18/M 61/F
Follow-up Data
Location Lower lip Infraorbital fissure Mandible Mandible Mandible Maxilla Lip Mandible Lower lip Upper lip Submandibular region Buccal mucosa Buccal mucosa Submandibular region Mandible Mandible
5 Years 6 Months
Mandible Mental foramen NA
IO Months I Year
NA NA 6 Months 4 Months 5 Months 1 Year 5 Years 2 Years 2 Years 3 Years 2 Years 4 Years NA 20
Months
Palate Buccal mucosa
3 Cases not documented 6 Weeks I Week
Cheek Mandible Palate
NA I5 Months 2 Years
Lingual nerve Mandible
21 Months 3.5 Years 3 Years 9 Months 15 Months 2 Years I Year
Tongue
Cheek Zygoma Maxillary sinus Mandible Submandibular gland Gingiva Maxilla
80 Months 2 Years 19 Months
DICERBO ET AL
FIGURE 1. Clinical appearance of the raised, slightly umbilicated, craterform mass.
in malignant schwannoma; Enzinger 33 demonstrated its presence in up to one half of malignant schwannomas studied. Although malignant melanoma has also been shown to be positive for the S- 100 marker, fibrosarcoma, leiomyosarcoma, and sarcomatoid undifferentiated carcinoma do not contain this protein.30 The
1219 presence of S- 100 protein, in combination with a thorough clinical history, and light and electron microscopy will enhance the pathologist’s ability to correctly identify a given tumor as malignant schwannoma. Authors who have studied the problems associated with this identification agree that the following clinicopathologic criteria should be applied5v30734: 1) the presence of von Recklinghausen’s disease, 2) gross or microscopic demonstration of the origin of the neoplasm within the anatomic compartment of a nerve, 3) close association of the origin of the neoplasm in a tumor having the histologic pattern of neurofibroma, 4) presence of a spindle-cell neoplasm arising at the site of a previously excised neurofibroma, 5) specific microscopic characteristics, including extreme pleomorphism, numerous mitoses, necrosis, and hypercellularity. There are varying opinions as to the appropriate modalities of therapy and survival rates associated with malignant peripheral nerve tumors. Performing a wide surgical excision is imperative. Das Gupta and Brasfield demonstrated that radiotherapy as the primary mode of treatment produced poor results. Other reports support the role of postoperative radiation.‘*30 The role of adjunctive chemotherapy is limited, except in occasional cases of metastatic disease. ‘v3’Cur-
FIGURE 2. A, Low-power photomicrogmph showing swirling masses of neoplastic cells separated by areas of fibrous connective tissue (hematoxylin-eosin stain, original magnification X40). B, Mediumpower view showing scattered mitotic figures within a spindle-cell background. Groups of spindle celis form a slightly whorled pattern, and demonstrate pleomorphism and nuclear hyperchromatism (hematoxylin-eosin stain, original magnification X100). C, High-power view showing several mitoses, bundles of parallel, spindle-shaped cells, and a slightly fibrillar background (hematoxylin-eosin stain, original magnification X200).
MALIGNANT SCHWANNOMA
OF THE PALATE
FIGURE 3. Electron micrographs of the lesion showing its characteristic features. A, Parallel spindle cells with basement membrane material (arrows) and dendritic processes (original magnification ~6,400). B, Myelin bodies composed of phospholipid material (arrowheads) are present along with scattered mitochondria (m), rough endoplasmic reticulum (arrow), and focally aggregated basement membrane material on the outer cell border (original magnification x 13,400).
rently, the best prognosis is given to patients with tumors less than 5 cm in diameter not arising from a lesion of von Recklinghausen’s disease, and treated with an aggressive surgical approach followed by postoperative radiotherapy.‘s2 The present report adds to the literature an additional case of intraoral malignant schwannoma; it is one of few reported on the palate and it occurred in a teenager. The initial diagnosis was probably made difficult by a small incisional specimen, a common pitfall in oral pathology. Fortunately, the ultimate surgical therapy was apparently curative, and postoperative radiotherapy was not required. References
3. 4. 5. 6.
7.
8. 9. 10.
1I. I. Toriumi DM, Atiyah RA, Murad T, et al: Extracranial neurogenic tumors ofthe head and neck. Otolaryngol Clin North Am 19: 609, 1986 2. Gullane PJ, Gilbert RW, Van Nostrand ANP, et al: Malignant
12.
schwannoma in the head and neck. J Otolaryngol 14: 17 I. 1985 Ghosh BC, Ghosh L, Huvas AC, et al: Malignant schwannoma: A clinicopathologic study. Cancer 3 I: 184, 1973 Das Gupta TK, Brasfield RD: Solitary malignant schwannoma. Ann Surg 171:419, 1970 Batsakis JG: Tumors of the Head and Neck. Baltimore, MD, Williams & Wilkins, 1974, pp 23 I-249 Martinez MG, Robinson LH: Primary neurogenic sarcomas of the oral region: A report of two cases. Ala J Med Sci 13:32, 1976 DeVom DT, Waldron CA: Malignant peripheral nerve tumors of the oral cavity: Review of the literature and report of a case. Oral Sura 14~56. 1961 Upton LG, Hay&rd JR, Kerr DA: Neurofibrosarcoma of the mandible. J Oral Sure 35:504. 1977 Kameyama Y: Malignant schwannoma of the maxilla in a patient without neurofibromatosis. Histopathology I 1:1205, 1987 Penfield W: Tumors of the sheath of the nervous system. Arch Neural Psycho1 27: 1298, I932 Murray MR, Stout AP, Bradley CF: Schwann cells vetsus fibroblast as the origin of the specific nerve sheath tumor. Am J Path01 16:41, 1940 Piatelli A, Angelone A, Pizzicanneha G, et al: Malignant schwannoma of the tongue: Report of a case and review of the literature. Acta Stomatol Belg 8 I:2 13, I984
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12a.Lewis D, Hart D: Tumors of peripheral nerves. Ann Surg 92: 961, 1930 13. Cutler EC, Gross RE: Neurofibroma and neurosarcoma of the peripheral nerves. Arch Surg 33:733, 1936 14. Bell WE: Neurogenic sarcoma of the mandible: Report of a case. J Am Dent Assoc 23:1351, 1936 15. Wilson S, Walsh JP: Neurogenic fibroma in a young child. North Am Dent J 44:123, 1948 16. DeLarue J, Haguenau M, Fiiez MM, et al: Neurinome malin de nerfdentaire inferiour: Etude anatomo-clinique. Rev Stomatol 5Ck529, 1949 17. Millard P, Busser F: Schwannome due maxillaire superieur d’evolution maligne. Ann Otolaryngol 69:706, 1952 18. Wise RA, Asbury GF: Malignant neurinomas of peripheral nerves. Ann Surg 136:874, 1952 19. Cuneo HM, Rand CW: Tumors of the gas&an ganglion: Tumor of the left gasserian ganglion associated with enlargement of the mandibular nerve: Review of literature and case report. J Neurosurg 9:423, 1952 20. Economou S Jr, Southwick HN, Slaughter DP: Neurofibrosarcomas of cranial nerve origin. Arch Surg 77:27 1, 1958 2 1. Villa VG, Buwag CA: Neurogenic fibrosarcoma in the mandible observed about one month after extraction of a lower third molar. Oral Surg 13:205, 1960 22. Ingram n: Radiology of tumors of the mandible. Clin Radio1 13:47, 1962 23. Hayward JR Trigeminal neurofibrosarcoma: Report of a case. J Oral Surg 21:518, 1963
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24. Shklar G, Meyer I: Neurogenic tumors of the mouth and jaws. Oral Surg 16:1075, 1963 25. Blankenship BJ, Stout R, Bradley T, et al: Neurofibrosarcoma of the palate associated with neurofibromatosis primary or metastatic. Oral Surg 22: 139, 1966 26. Hammond HL, Calderwood RG: Malignant peripheral nerve tumors of the oral cavity: Review of the literature and report of a case. Oral Smg Oral Med Oral Pathol28:97, 1969 27. Eversole LR, Schwartz DW, Sabes WR: Central and peripheral fibrogenic and neurogenic sarcoma of the oral regions. Oral Surg 36:49, 1973 28. Wasserman BS, Finkleman A, John M, et al: Malignant schwannoma of the lingual nerve: A case report. H Irak Med 32:67, 1977 29. Shimsuna, Kanemitsu: Malignant schwannoma of the mandible. Int J Oral Maxillofac Surg 15:772, 1986 30. Piscioli F, Antolini M, Pusiol T, et al: Malignant schwannoma of the submandibular gland: A case report. ORL J Otorhinolaryngol Relat Spec 48: 156, I986 3 I. Gughelmotti MB, Penar C, Dominguez Fv: Malignant schwannoma of the gingiva. Int J Oral Maxillofac Surg 16:492, 1987 32. Moore BW: A soluble protein characteristic ofthe nervous system. Res Commun Chem Path01 Pharmacol 19:739, 1965 33. Enzinger FM: Classification and diagnosis of peripheral neural tumors. Istocitopatologia 5: 157, 1983 34. Trojanowski JQ, Kleinman GM, Proppe KH: Malignant tumors of nerve sheath origin. Cancer 46: 1202, 1980 35. Das Gupta TK: Tumors of peripheral nerves. Clin Neurosurg 25:574, 1977
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Large Odontogenic Myxoma of the Mandible Treated by Sagittal Ramus Osteotomy and Peripheral Ostectomy GORDON B. WONG, MSc, DDS*
The odontogenic myxoma is a relatively rare lesion of the jaws, and is reported to represent 0.04% to 0.6% of total surgical specimens submitted to oral pathology departments.‘,* It represents approximately 3% of all odontogenic tumors.’ The mean age at the time of diagnosis varies from 25 to 35 years, with a distinct predominance in females and a predilection for the mandible.2-5 However, an equal incidence of male and female cases also has been reported,6 as well as an equal
* In private practice, Sault Ste Marie, Ontario, Canada. Address correspondence and reprint requests to Dr Wong: 350 Queen St E, Sault Ste Marie, Ontario, P6A 1Zl Canada. Q 1992 American Association of Oral and Maxillofacial Surgeons 0278-2391/92/501
l-001 4$3.00/O
maxillary and mandibular cases.’ The lesion may have three different radiographic presentations.’ The “honey-comb” or “tennis-racquet” appearance is most common, although unilocular or multilocular “soapbubble” appearances also occur. When the tumor has perforated the cortex with the formation of multiple, radiating spicules, it may have a “sunray” or “sunburst” appearance. ‘2’ The usual clinical presentation is that of an asymptomatic, painless swelling, which may also include displaced teeth and paresthesia.* The odontogenic origin of the tumor has been mainly circumstantial, and is based on the predominant occurrence in tooth-bearing regions of the jaws, histologic similarity to the stellate reticulum of a forming tooth, and clinical behavior resembling that of the ameloblastoma. The presence of odontogenic epithelium in some cases also has led some to support this
