NEURILEMMOMA
OF THE MENTAL NERVE
fected mucocele.’ The treatment of these lesions is enucleation and curettage to prevent further expansion and destruction due to increased intraluminal pressure.2 The differential diagnosis of bilateral lesions of the maxilla includes basal cell nevus syndrome (multiple odontogenic keratocysts), the brown tumor of hyperparathyroidism, multiple myeloma, cherubism, fibrous dysplasia, central giant cell granuloma, anuerysmal bone cyst, hemangioma, antral carcinoma or other malignancy, cholesteatoma, mucus retention cyst, and odontogenic infection. Only histologic evaluation coupled with clinical behavior assures the proper diagnosis. FIGURE 8. Photomicrograph showing cholesterol granulomas and foreign-body giant cells (hematoxylin-eosin stain, original magnitication X 200).
from inflammation, allergy, or malignancy. Many of the signs and symptoms mimic an invasive carcinoma of the sinus and this must be stressed in making the proper diagnosis.’ It may be possible to make this distinction with CT, as mucoceles do not enhance after administration of contrast material, whereas tumors do.9 The more common mucoceles are secondary, and result from past surgical intervention (especially Caldwell-Luc procedures) or trauma. They are referred to as postoperative mucoceles or surgical ciliated cysts of the maxilla.8 These are quite common in Japan, where they often treat sinus disease aggressively with surgery.“’ A mucocele contains sterile mucus and a mucopyocele is simply an in-
J Oral Maxillofac
References 1. Natvig K, Larsen TE: Mucocele of the paranasal sinuses. J Laryngol Otol 92: 1075. 1978 2. Barsley RE, Thunthy KH, Weir JC: Maxillary sinus mucocele: Report of an unusual case. Oral Surg 58:499, 1984 3. Gardner DG: Pseudocysts and retention cysts of the maxillary sinus. Oral Surg 58:561, 1984 4. Halstead CL: Mucosal cysts of the maxillary sinus: report of 75 cases. J Am Dent Assoc 87:1435, 1973 5. Ruprecht A, Batniji S, El-Neweihi E: Mucous retention cyst of the maxillary sinus. Oral Surg 62:728, 1986 6. Gardner DG, Gullane PG: Mucoceles of the maxillary sinus. Oral Surg 62:538, 1986 7. Zizmor J, Noyek AM, Chapnik JS: Mucocele of the paranasal sinuses, Can J Otolaryngol 1974 (suppl 1) 8. East D: Mucoceles of the maxillary antrum: Description, case reports and review of the literature, J Laryngol Otol 99149, 1985 9. Som PM, Shugar JMA: Antral mucoceles: A new look. Comput Assist Tomogr 4:484, 1980 10. Hasegawa M, Saito Y, Watanabe I, et al: Postoperative mucoceles of the maxillary sinus. Rhinology 17:253, 1979
Surg
49:196-zoo,1991
Neurilemmoma
of the Mental Nerve
ZVI ARTZI, DMD,* SHLOMO TAICHER,
* Lecturer, Department of Periodontology, The Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Israel. t Head, Department of Oral and Maxillofacial Surgery, Sheba Medical Center, Tel Hashomer, Israel. $ Resident, Department of Pathology, Sheba Medical Center, Tel Hashomer, Israel. Address correspondence and reprint requests to Dr Artzi: Department of Periodontology, The Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel.
0 1991 American Association geons 0278-2391/91/4902-0018$3.00/O
of Oral and Maxillofacial
Sur-
DMD,t
AND DVORA NASS, MD*
Neurilemmoma (neurinoma, Schwann cell tumor, schwannoma) is a benign, encapsulated perineural tumor of neuroectodermal derivation that originates from the Schwann cells of the neural sheath. It is composed primarily of Schwann cells in a poorly collagenized stroma. The tumor is solitary, smooth-surfaced, slowgrowing, and asymptomatic, and may have a long duration at the time of initial examination. It may develop at any age, and there is no gender predilection. The lesion may be intraosseous (central schwannomas) or located in the soft tissues (periphera1 schwannomas).
ARTZl ET AL
In the head and neck, the tumor has been reported to involve the 5th. 7th, 8th, 9th, Ilth, and 12th cranial nerves.le7 A report of a rare lesion involving the mental nerve is presented. Report of a Case A 66-year-old edentulous woman was referred to Sheba Medical Center, Department of Oral and Maxillofacial Surgery, complaining of swelling in the right mental region and associated with paresthesia. She was in excellent health and all blood tests were within normal limits. Palpation revealed a solid mass in the area of the right mental nerve, which was slightly painful upon pressure. A radiograph showed no significant findings. On surgical exploration, a tumor was found attached to the distal aspect of the mental nerve (Fig 1). This was carefully dissected and excised (Fig 2). Microscopic examination showed a tumor composed of compact spindle cells with twisted nuclei, indistinct cytoplasmic borders, and occasional clear intranuclear vacuoles, arranged in short bundles or interlacing fascicles. These features are characteristic of a neurilemmoma with an Antoni type A pattern (Figs 3 to 5). Hypoesthesia was still present at the time of suture removal, but this resolved within a few days. The patient currently has normal sensation.
FIGURE 2. lntraoperative view showing the preserved mental nerve following removal of the tumor.
A total of 184 cases of intraoral neurilemmoma have been reported (Table l).8-3’ Of these, 31 cases were intraosseous (17) and all except one were located in the mandible. The age of these patients ranged from 7 years to 84 years, with an average age of 36; the female to male ratio was 60/40. Of the remaining 153 extraosseous lesions (83%), the most common site was the mobile portion of the tongue,
with 76 cases (50%). Seventeen cases (I 1%) were reported in the buccal mucosa, 17 ( 11%) in the floor of the mouth, 14 (9%) in the palate, 9 (6%) in the gingiva, 8 (5%) in the vestibule, 8 (5%) in the lips, and 3 (2%) in the salivary gland. Only 3 cases were reported as originating from the mental nerve. 20.2x.32 The extraosseous tumor may occur at any age (5 months to 84 years), but usually occurs in the third and fourth decades; the average age of reported cases was 31.7 years. This is compatible with previous literature reviews.8S’6.33 The gender ratio of the soft-tissue schwannomas was similar to that of the intraosseous types. Tumors originating from the peripheral nerve in the oral cavity are rare. The schwannoma is usually sessile or submucosal, firm, rubbery, circumscribed, and encapsulated. The larger tumors are
Intraoperative view showing the encapsulated tumor attached to the distal aspect of the mental nerve.
FIGURE 3. Photomicrograph showing Antoni type A tissue and adjacent capsule (upper left) (hematoxylin-eosin, original magnification X25).
Discussion
FIGURE
1.
198
FIGURE 4. Photomicrograph showing elongated spindle cells with indistinct cell membranes arranged in interlacing fascicles (hematoxylin-eosin, original magnification X 100).
irregularly lobulated and may be partly cystic following secondary changes, or xanthomatous with an opaque creamy-yellow appearance. The schwannoma occurs at any age; however, when involving the oral cavity, it tends to appear in adults rather than in children as compared with the solitary neurotibroma. The site of some lesions is so characteristic that diagnosis is not difficult. Nevertheless, a differentiation between schwannoma, traumatic neuroma, and solitary neurofibroma always should be considered. Other disorders that involve the peripheral nerves are neurofibromatosis, multiple endocrine neoplasia III (multiple mucosal neuromas with carcinoma of the thyroid and pheochromocytoma), malignant schwannoma (so-called neurogenic sarcoma), and rare neural tumors such as the palisaded
FIGURE 5. Higher magnification of Figure 4 (hematoxylineosin, original magnification X400).
NEURILEMMOMA
OF THE MENTAL NERVE
and encapsulated neuroma, nerve sheath myxoma, and ganglioneurofibroma.34,35 The neurilemmoma were first described by Verocay,36,37 who referred to them as neurinomas. Stout’ used the term neurilemmoma, believing that the tumor originated from Schwann cells. The etiology of schwannoma is unknown, but is thought to originate from a proliferation of Schwann cells within the perineurium causing a displacement and compression of the adjacent nerve. Diagnosis is confirmed by microscopic examination. The schwannoma has two distinct components: Antoni type A and Antoni type B tissue. Antoni type A tissue consists of Schwann cells arranged in compact, twisted bundles, associated with delicate reticulin fibers and spindle-shaped nuclei aligned closely in parallel rows forming a palisading pattern. Between the rows, there are fine, cytoplasmic fibrils extending to form a delicate fibrillar zone, with acellular, hyalinized, eosinophilic masses termed Verocay bodies. The Antoni type B components are indistinct zones of irregularly arranged masses of elongated cells and fibers similar in appearance to neurofibroma. These unorganized masses appear to have areas of cystic degeneration and edema. Electron microscopy,2”38 demonstrates the presence of a lamellar pattern of thin, elongated cells with numerous convoluted cytoplasmic processes surrounded by a basal lamina and separated by an intercellular, granular basement membrane material similar to Antoni type A tissue. The Antoni B cell is also coated with a basement membrane, but it contains numerous organelles and vacuoles showing a high degree of metabolic activity, storage, and digestive properties.38 The cells vary considerably in size, shape, and chromaticity, but do not suggest malignancy unless numerous bizarre cells are noted. The schwannoma is usually encapsulated by dense fibrous connective tissue. Nerve tissue may be found in the outer aspect of the capsule. Ultrasonographically the schwannoma shows features of sonolucency due to its uniform cellularity, posterior acoustic enhancement, refractive edge shadow, smooth margin, and lack of a discernible ~all.~~-~’ Treatment is surgical excision; because the tumor is well-encapsulated, excision is easily performed. However, special attention should be paid to preservation of the associated adjacent nerve by careful dissection and excision. The approach advocated by Thoma,32 ie, sectioning the nerve to prevent the formation of a large deforming tumor, is not recommended. Unlike neurofibroma, the prognosis is excellent, as malignant transformation is extremely rare and recurrence unlikely.
199
ARTZI ET AL
Table 1.
Case Reports of Neurilemmoma Involving the Oral Cavity
Author(s)
No. of Floor Case Buccal of the Reports Tongue Mucosa Palate Gingiva Mouth Vestibular
Hatziotis & Asprides (1%7)X Literature review I06 Case reports 4 stout (130-2 (1926-1944)‘* oral ) Kragh et al (143-10 (1960)‘0* oral) Thorsrud (380-6 (1960)“’ oral) Samter et al (1960)” I Oberman & Sullenger (1967)‘j 6 Crawford & Korcbin (1%8)14 5 Eversole (1969)” I8 Cherrick & Eversole (197l)‘h I8 Shimura et al (1973)” I Sugimura et al (1974)‘s I Swangsilpa et al ( 1976)19 2 Gall0 et al (1977)” 5 Ellis et al (1977)” 2 Rengasway (1978)“ 1 Chen & Miller (1979)” 6 Barker & Dunlap (l979?4 Sciubba & Sachs (1980)” Sattertield et al (1981)‘h Schofield & Gardner (1981)” Zachariades (l984?* Murphy & Giunta (1985)” Sastry & Mani (1985)‘” Marzola et al (1988)”
59
9
2
I
I1
6
10
4
Mental Not Nerve Lip Identified
I
Salivary Gland
Intraosseous
6
I (2)
(5)
(11
(4)
(3)
(1)
I Mandibular
(2)
2
3
2
I
I7 Mandibular
1 Maxillary 8
3 1 Mandibular
I Mandibular I
I Mandibular I
2 2 Mandibular
I Mandibular 2
I
I I Mandibular
I Mandibular I Mandibular I Mandibular
I Mandibular I
I Mandibular
* Reported in literature review of Hatziotis and Asptides.’ Cases of Das Gupta33 were excluded because there was no differentiation between neurotibroma and neurilemmoma.
References 1. Hingorani RK: Neurilemoma of facial nerve. J Laryngol Otol 84:1275, 1970 2. Gibson WS, Hora JF: Intraparotid facial neurilemoma. Ann Otol 79:412, 1970 3. Arenberg IK, McCeary HS: Neurilemoma of jugular foramen. Laryngoscope 81:544. 1971
4. Winborn CD, Martinez DM, Holding BF. et al: Neurilemoma of the hypoglossal nerve: Report of a case. Arch Otolaryngol 69:583, 1959 5. Whittam DE, Morris TM: Neurilemoma of the larynx. J Laryngol Otol 84:747, 1970 6. Wiet RJ. Lotan AN, Brackmann DE: Neurilemoma of the chorda tympani nerve. Otolaryngol Head Neck Surg 93: 119, 1985
FIRST BRANCHIAL
7. Nager GT: Neurinomas 8.
9. 10.
11.
of the trigeminal nerve. Am J Otolaryngol 5:3Ol, 1984 Hatziotis JC, Asprides H: Neurilemoma of the oral cavity. Oral Surg 24510, 1967 Stout AP: The peripheral manifestations of the specific nerve sheath tumor. Am J Cancer 241751, 1935 Kragh LV, Soule EH, Masson JK: Benign and malignant neurilemmomas of the head and neck. Surg Gynecol Obstet 11:211, 1960 Thorsrud G: Neurinoma. Acta Chir Stand 252:9, 1960
49200-204,
26. 27. 28.
(SUPPl)
12. Samter TG, Vellios F, Shaffer WG: Neurilemmoma of bone. Radiology 75:215, 1960 13. Oberman HA, Sullenger G: Neurogenous tumors of the head and neck. Cancer 20: 1992, 1967 14. Crawford WH, Korcbin LK: Neurilemmomas of the oral cavity. J Oral Surg 26:651, 1968 15. Eversole LR: Central benign and malignant neural neoplasms of the jaws: A review. J Oral Surg 27:716, 1969 16. Cherrick HM, Eversole LR: Benign neural sheath neoplasm of the oral cavity. Oral Surg Oral Med Oral Path01 32900, 1971 17. Shimura K, Allen C, Kinashita Y, et al: Central neurilemmoma of the mandible. J Oral Surg 31:363, 1973 18. Sugimura M, Shirasuna K, Yoshimura Y. et al: A case of neurilemmoma in the mandible. Int J Oral Surg 3:194, 1974 19. Swangsilpa K, Winther JE, Nybroe L: Neurilemmonas in the-oral cavity. J Dent 4:237, 1976 20. Gallo WJ. Moss M. Shaoiro DN. et al: Neurilemoma: Review of the literature and report of five cases. J Oral Surg 351235. 1977 21. Ellis GL, Abrams AM, Melrose RJ: Interosseous benign neural sheath neoplasms of the jaws. Oral Surg 44:731, 1977 22. Rengasway V: Central neurilemmoma of the jaws: Review of the literature and case report. Int J Oral Surg 7:300, 1978 23. Chen SY, Miller A: Neurotibroma and schwannoma of the oral cavity-A clinical and ultrastructural study. Oral Surg 471522, 1979 24. Barker BF, Dunlap CL: Intraosseous benign nerve sheath J Oral Maxillofac
25.
29. 30. 31. 32. 33. 34. 35. 36.
37. 38.
39.
40. 41.
CLEFT ANOMALY
neoplasms of the jaws: A review of the literature and case report. Presented to the 33rd Annual Meeting of the American Academy of Oral Pathology, San Diego, 1979 Sciubba JJ, Sachs SA: Schwannoma of the inferior alveolar nerve in association with the organ of Chievitz. J Oral Pathol 9: 16, 1980 Satterfield SD, Elzay RP, Mercuri L: Mandibular central schwannoma: Report of a case. J Oral Surg 39:776, 1981 Schofield IDF, Gardner DG: Central neurilemmoma of the mandible. J Can Dent Assoc 47:175. 1981 Zachariades N: Schwannoma of the oral cavity. Review of the literature and report of a case. J Oral Med 39:41, 1984 Murphy J, Giunta JL: Atypical central neurilemmoma of the mandible. Oral Surg 59:275, 1984 Sastry KARH, Mani NJ: Peripheral schwannoma of the mandible. J Oral Med 40:98, 1985 Marzola C, Borguetti MJ, Consolaro A: Neurilemmoma of the mandible. J Oral Maxillofac Surg 46:330, 1988 Thoma KH: Neurogenic Tumors in Oral Surgery (ed 51, vol II. St Louis, MO, Mosby, 1969 Das Gupta TK, Brasfield RD, Strong EW. et al: Benign solitary schwannomas (neurilemomas). Cancer 24:355, 1969 Shklar G, Meyer I: Neurogenic tumors of the mouth and jaws. Oral Surg 16:1075. 1963 Wright BA, Jackson D: Neural tumors of the oral cavity. Oral Surg 49:509. 1980 Stout AP: Tumors of the peripheral nervous system, in Harkin JC, Reed RJ teds): Atlas of Tumor Pathology, Set II, Fast 3. Washington, DC, Armed Forces Institute of Pathology, 1%9 Verocay J: Zur Kennitnis der “Neurolibrome.” Beitr Z Path01 Anat 48: 1. 1910 Russell DS. Rubinstein LJ: Pathology of Tumors of the Nervous System (ed 3). Baltimore. Williams & Wilkins, 1972, p 284 (chapt 12) Chinn DH, Filly RA, Callen PW: Unusual ultrasonographic appearance of a solid schwannoma. J Clin Ultrasound 10:243. 1982 Hughes DG, Wilson DJ: Ultrasound appearances of peripheral nerve tumours. Br J Radio1 59:1041, 1986 Obayashi T. Itoh K. Nakano A: Ultrasonic diagnosis of schwannoma. Neurology 37:1817, 1987
Surg
1991
First Branchial
Cleft Anomaly:
A Case Report LUIS MIGUEL REDONDO GONZALEZ, MD,* JOSE MIGUEL GARCiA CANTERA, MD,* ALBERT0 VERRIER HERNANDEZ, MD, DMD,* AND HENAR BORREGO PINTADO, MDt
Received from the “Pfo de1 Rio Hortega” Hospital, Valladolid, Spain. * Resident Doctor, Maxillofacial Surgery Service. t Pathology Service. Dedicated to the Service of Oral and Maxillofacial Surgery of Valladolid and the Dr C. Idiguez Lobeto. Address correspondence and reprint requests to Dr Gonzalez: Servicio de Cirugia Oral y Maxilofacial, Hospital “Del Rio Hortega,” Avda de Santa Teresa S/n, 47010 Valladolid, Spain. 0 1991 American geons
Association
0278-2391/91/4902-0019$3.00/O
of Oral and Maxillofacial
Sur-
The earliest report of a first branchial cleft anomaly was made by Virchow’ in 1865. He described a child with several malformations that included a fistula between the nasopharynx and the inferoposterior area of the auricule. Several cases’& have since been reported and this has led both to a better understanding of these malformations and to determination of their incidence in comparison with other anomalies (1% to 8%). It has become clear that branchial cysts occur twice as often as other malformations such as sinus
OF THE MENTAL NERVE
fected mucocele.’ The treatment of these lesions is enucleation and curettage to prevent further expansion and destruction due to increased intraluminal pressure.2 The differential diagnosis of bilateral lesions of the maxilla includes basal cell nevus syndrome (multiple odontogenic keratocysts), the brown tumor of hyperparathyroidism, multiple myeloma, cherubism, fibrous dysplasia, central giant cell granuloma, anuerysmal bone cyst, hemangioma, antral carcinoma or other malignancy, cholesteatoma, mucus retention cyst, and odontogenic infection. Only histologic evaluation coupled with clinical behavior assures the proper diagnosis. FIGURE 8. Photomicrograph showing cholesterol granulomas and foreign-body giant cells (hematoxylin-eosin stain, original magnitication X 200).
from inflammation, allergy, or malignancy. Many of the signs and symptoms mimic an invasive carcinoma of the sinus and this must be stressed in making the proper diagnosis.’ It may be possible to make this distinction with CT, as mucoceles do not enhance after administration of contrast material, whereas tumors do.9 The more common mucoceles are secondary, and result from past surgical intervention (especially Caldwell-Luc procedures) or trauma. They are referred to as postoperative mucoceles or surgical ciliated cysts of the maxilla.8 These are quite common in Japan, where they often treat sinus disease aggressively with surgery.“’ A mucocele contains sterile mucus and a mucopyocele is simply an in-
J Oral Maxillofac
References 1. Natvig K, Larsen TE: Mucocele of the paranasal sinuses. J Laryngol Otol 92: 1075. 1978 2. Barsley RE, Thunthy KH, Weir JC: Maxillary sinus mucocele: Report of an unusual case. Oral Surg 58:499, 1984 3. Gardner DG: Pseudocysts and retention cysts of the maxillary sinus. Oral Surg 58:561, 1984 4. Halstead CL: Mucosal cysts of the maxillary sinus: report of 75 cases. J Am Dent Assoc 87:1435, 1973 5. Ruprecht A, Batniji S, El-Neweihi E: Mucous retention cyst of the maxillary sinus. Oral Surg 62:728, 1986 6. Gardner DG, Gullane PG: Mucoceles of the maxillary sinus. Oral Surg 62:538, 1986 7. Zizmor J, Noyek AM, Chapnik JS: Mucocele of the paranasal sinuses, Can J Otolaryngol 1974 (suppl 1) 8. East D: Mucoceles of the maxillary antrum: Description, case reports and review of the literature, J Laryngol Otol 99149, 1985 9. Som PM, Shugar JMA: Antral mucoceles: A new look. Comput Assist Tomogr 4:484, 1980 10. Hasegawa M, Saito Y, Watanabe I, et al: Postoperative mucoceles of the maxillary sinus. Rhinology 17:253, 1979
Surg
49:196-zoo,1991
Neurilemmoma
of the Mental Nerve
ZVI ARTZI, DMD,* SHLOMO TAICHER,
* Lecturer, Department of Periodontology, The Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Israel. t Head, Department of Oral and Maxillofacial Surgery, Sheba Medical Center, Tel Hashomer, Israel. $ Resident, Department of Pathology, Sheba Medical Center, Tel Hashomer, Israel. Address correspondence and reprint requests to Dr Artzi: Department of Periodontology, The Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel.
0 1991 American Association geons 0278-2391/91/4902-0018$3.00/O
of Oral and Maxillofacial
Sur-
DMD,t
AND DVORA NASS, MD*
Neurilemmoma (neurinoma, Schwann cell tumor, schwannoma) is a benign, encapsulated perineural tumor of neuroectodermal derivation that originates from the Schwann cells of the neural sheath. It is composed primarily of Schwann cells in a poorly collagenized stroma. The tumor is solitary, smooth-surfaced, slowgrowing, and asymptomatic, and may have a long duration at the time of initial examination. It may develop at any age, and there is no gender predilection. The lesion may be intraosseous (central schwannomas) or located in the soft tissues (periphera1 schwannomas).
ARTZl ET AL
In the head and neck, the tumor has been reported to involve the 5th. 7th, 8th, 9th, Ilth, and 12th cranial nerves.le7 A report of a rare lesion involving the mental nerve is presented. Report of a Case A 66-year-old edentulous woman was referred to Sheba Medical Center, Department of Oral and Maxillofacial Surgery, complaining of swelling in the right mental region and associated with paresthesia. She was in excellent health and all blood tests were within normal limits. Palpation revealed a solid mass in the area of the right mental nerve, which was slightly painful upon pressure. A radiograph showed no significant findings. On surgical exploration, a tumor was found attached to the distal aspect of the mental nerve (Fig 1). This was carefully dissected and excised (Fig 2). Microscopic examination showed a tumor composed of compact spindle cells with twisted nuclei, indistinct cytoplasmic borders, and occasional clear intranuclear vacuoles, arranged in short bundles or interlacing fascicles. These features are characteristic of a neurilemmoma with an Antoni type A pattern (Figs 3 to 5). Hypoesthesia was still present at the time of suture removal, but this resolved within a few days. The patient currently has normal sensation.
FIGURE 2. lntraoperative view showing the preserved mental nerve following removal of the tumor.
A total of 184 cases of intraoral neurilemmoma have been reported (Table l).8-3’ Of these, 31 cases were intraosseous (17) and all except one were located in the mandible. The age of these patients ranged from 7 years to 84 years, with an average age of 36; the female to male ratio was 60/40. Of the remaining 153 extraosseous lesions (83%), the most common site was the mobile portion of the tongue,
with 76 cases (50%). Seventeen cases (I 1%) were reported in the buccal mucosa, 17 ( 11%) in the floor of the mouth, 14 (9%) in the palate, 9 (6%) in the gingiva, 8 (5%) in the vestibule, 8 (5%) in the lips, and 3 (2%) in the salivary gland. Only 3 cases were reported as originating from the mental nerve. 20.2x.32 The extraosseous tumor may occur at any age (5 months to 84 years), but usually occurs in the third and fourth decades; the average age of reported cases was 31.7 years. This is compatible with previous literature reviews.8S’6.33 The gender ratio of the soft-tissue schwannomas was similar to that of the intraosseous types. Tumors originating from the peripheral nerve in the oral cavity are rare. The schwannoma is usually sessile or submucosal, firm, rubbery, circumscribed, and encapsulated. The larger tumors are
Intraoperative view showing the encapsulated tumor attached to the distal aspect of the mental nerve.
FIGURE 3. Photomicrograph showing Antoni type A tissue and adjacent capsule (upper left) (hematoxylin-eosin, original magnification X25).
Discussion
FIGURE
1.
198
FIGURE 4. Photomicrograph showing elongated spindle cells with indistinct cell membranes arranged in interlacing fascicles (hematoxylin-eosin, original magnification X 100).
irregularly lobulated and may be partly cystic following secondary changes, or xanthomatous with an opaque creamy-yellow appearance. The schwannoma occurs at any age; however, when involving the oral cavity, it tends to appear in adults rather than in children as compared with the solitary neurotibroma. The site of some lesions is so characteristic that diagnosis is not difficult. Nevertheless, a differentiation between schwannoma, traumatic neuroma, and solitary neurofibroma always should be considered. Other disorders that involve the peripheral nerves are neurofibromatosis, multiple endocrine neoplasia III (multiple mucosal neuromas with carcinoma of the thyroid and pheochromocytoma), malignant schwannoma (so-called neurogenic sarcoma), and rare neural tumors such as the palisaded
FIGURE 5. Higher magnification of Figure 4 (hematoxylineosin, original magnification X400).
NEURILEMMOMA
OF THE MENTAL NERVE
and encapsulated neuroma, nerve sheath myxoma, and ganglioneurofibroma.34,35 The neurilemmoma were first described by Verocay,36,37 who referred to them as neurinomas. Stout’ used the term neurilemmoma, believing that the tumor originated from Schwann cells. The etiology of schwannoma is unknown, but is thought to originate from a proliferation of Schwann cells within the perineurium causing a displacement and compression of the adjacent nerve. Diagnosis is confirmed by microscopic examination. The schwannoma has two distinct components: Antoni type A and Antoni type B tissue. Antoni type A tissue consists of Schwann cells arranged in compact, twisted bundles, associated with delicate reticulin fibers and spindle-shaped nuclei aligned closely in parallel rows forming a palisading pattern. Between the rows, there are fine, cytoplasmic fibrils extending to form a delicate fibrillar zone, with acellular, hyalinized, eosinophilic masses termed Verocay bodies. The Antoni type B components are indistinct zones of irregularly arranged masses of elongated cells and fibers similar in appearance to neurofibroma. These unorganized masses appear to have areas of cystic degeneration and edema. Electron microscopy,2”38 demonstrates the presence of a lamellar pattern of thin, elongated cells with numerous convoluted cytoplasmic processes surrounded by a basal lamina and separated by an intercellular, granular basement membrane material similar to Antoni type A tissue. The Antoni B cell is also coated with a basement membrane, but it contains numerous organelles and vacuoles showing a high degree of metabolic activity, storage, and digestive properties.38 The cells vary considerably in size, shape, and chromaticity, but do not suggest malignancy unless numerous bizarre cells are noted. The schwannoma is usually encapsulated by dense fibrous connective tissue. Nerve tissue may be found in the outer aspect of the capsule. Ultrasonographically the schwannoma shows features of sonolucency due to its uniform cellularity, posterior acoustic enhancement, refractive edge shadow, smooth margin, and lack of a discernible ~all.~~-~’ Treatment is surgical excision; because the tumor is well-encapsulated, excision is easily performed. However, special attention should be paid to preservation of the associated adjacent nerve by careful dissection and excision. The approach advocated by Thoma,32 ie, sectioning the nerve to prevent the formation of a large deforming tumor, is not recommended. Unlike neurofibroma, the prognosis is excellent, as malignant transformation is extremely rare and recurrence unlikely.
199
ARTZI ET AL
Table 1.
Case Reports of Neurilemmoma Involving the Oral Cavity
Author(s)
No. of Floor Case Buccal of the Reports Tongue Mucosa Palate Gingiva Mouth Vestibular
Hatziotis & Asprides (1%7)X Literature review I06 Case reports 4 stout (130-2 (1926-1944)‘* oral ) Kragh et al (143-10 (1960)‘0* oral) Thorsrud (380-6 (1960)“’ oral) Samter et al (1960)” I Oberman & Sullenger (1967)‘j 6 Crawford & Korcbin (1%8)14 5 Eversole (1969)” I8 Cherrick & Eversole (197l)‘h I8 Shimura et al (1973)” I Sugimura et al (1974)‘s I Swangsilpa et al ( 1976)19 2 Gall0 et al (1977)” 5 Ellis et al (1977)” 2 Rengasway (1978)“ 1 Chen & Miller (1979)” 6 Barker & Dunlap (l979?4 Sciubba & Sachs (1980)” Sattertield et al (1981)‘h Schofield & Gardner (1981)” Zachariades (l984?* Murphy & Giunta (1985)” Sastry & Mani (1985)‘” Marzola et al (1988)”
59
9
2
I
I1
6
10
4
Mental Not Nerve Lip Identified
I
Salivary Gland
Intraosseous
6
I (2)
(5)
(11
(4)
(3)
(1)
I Mandibular
(2)
2
3
2
I
I7 Mandibular
1 Maxillary 8
3 1 Mandibular
I Mandibular I
I Mandibular I
2 2 Mandibular
I Mandibular 2
I
I I Mandibular
I Mandibular I Mandibular I Mandibular
I Mandibular I
I Mandibular
* Reported in literature review of Hatziotis and Asptides.’ Cases of Das Gupta33 were excluded because there was no differentiation between neurotibroma and neurilemmoma.
References 1. Hingorani RK: Neurilemoma of facial nerve. J Laryngol Otol 84:1275, 1970 2. Gibson WS, Hora JF: Intraparotid facial neurilemoma. Ann Otol 79:412, 1970 3. Arenberg IK, McCeary HS: Neurilemoma of jugular foramen. Laryngoscope 81:544. 1971
4. Winborn CD, Martinez DM, Holding BF. et al: Neurilemoma of the hypoglossal nerve: Report of a case. Arch Otolaryngol 69:583, 1959 5. Whittam DE, Morris TM: Neurilemoma of the larynx. J Laryngol Otol 84:747, 1970 6. Wiet RJ. Lotan AN, Brackmann DE: Neurilemoma of the chorda tympani nerve. Otolaryngol Head Neck Surg 93: 119, 1985
FIRST BRANCHIAL
7. Nager GT: Neurinomas 8.
9. 10.
11.
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Surg
1991
First Branchial
Cleft Anomaly:
A Case Report LUIS MIGUEL REDONDO GONZALEZ, MD,* JOSE MIGUEL GARCiA CANTERA, MD,* ALBERT0 VERRIER HERNANDEZ, MD, DMD,* AND HENAR BORREGO PINTADO, MDt
Received from the “Pfo de1 Rio Hortega” Hospital, Valladolid, Spain. * Resident Doctor, Maxillofacial Surgery Service. t Pathology Service. Dedicated to the Service of Oral and Maxillofacial Surgery of Valladolid and the Dr C. Idiguez Lobeto. Address correspondence and reprint requests to Dr Gonzalez: Servicio de Cirugia Oral y Maxilofacial, Hospital “Del Rio Hortega,” Avda de Santa Teresa S/n, 47010 Valladolid, Spain. 0 1991 American geons
Association
0278-2391/91/4902-0019$3.00/O
of Oral and Maxillofacial
Sur-
The earliest report of a first branchial cleft anomaly was made by Virchow’ in 1865. He described a child with several malformations that included a fistula between the nasopharynx and the inferoposterior area of the auricule. Several cases’& have since been reported and this has led both to a better understanding of these malformations and to determination of their incidence in comparison with other anomalies (1% to 8%). It has become clear that branchial cysts occur twice as often as other malformations such as sinus
