Pathology of the Head and Neck

126 P.J. Slootweg4Fig. 4.38. Melanotic neuroectodermal tumour of infancy consistsof small dark cells and larger cells with vesicular nuclei. Melaninis usually associated with the latter cell populationpy consists of debulking and irradiation. Five-year survivalrate is approximately 50%. Histologic features relatedwith prognosis have not been identified [29]. Metastaticdisease is unusual [25].4.7.3 Melanotic NeuroectodermalTumour of InfancyICD-O:9363/0Cells derived from the neural crest play a major role inthe formation of the jaws and teeth. These cells are alsothought to be the source from which the melanotic neuroectodermaltumour of infancy develops [106]. Most ofthe lesions occur before the age of 1 year. The majorityof them occur in the anterior maxilla [68].The tumour shows dense fibrous stroma with nestscomposed of two different cell types: centrally placedsmall dark cells without any discernable cytoplasm andperipherally located larger cells with vesicular nucleiand ample cytoplasm with melanin pigment (Fig. 4.38)[9, 68, 113]. Maturation of the small cells to ganglioncells has been reported [144]. Although the cells may beatypical, mitotic figures are rare [9]. Sometimes, a transitionof the large cells to osteoblasts forming tiny bonytrabeculae can be observed [157]. The lesion is not encapsulated.Immunohistochemically, the large cells are positivefor a wide variety of cytokeratins, neuron-specific enolase,S-100, HMB45 and chromogranin. The small cellsshow positivity for CD56, neuron-specific enolase, synaptophysinand chromogranin [9]. This pattern can besummarised as evidence for neural, melanocytic and epithelialdifferentiation. In addition, the large cells havebeen shown to be positive for vimentin [157]. Ultrastructurally,the small cells show neurosecretory granulesand the large cells show melanosomes at differentstages of development [113].Quite often, immature odontogenic tissues form partof the material excised or biopsied, due to the early ageof occurrence and the close association of the tumourwith tooth germs. This should not be mistaken as evidenceof an odontogenic tumour. The highly characteristichistological pattern leaves no room for other differentialdiagnostic considerations.Clinically, melanotic neuroectodermal tumour of infancymanifests as a rapidly growing blue tissue mass,usually at the anterior alveolar maxillary ridge. Radiologically,bone resorption may be seen, although this isdifficult to evaluate in the delicate bony structures of theinfantile maxilla. Tooth germs are displaced and may liewithin the tumour mass. Conservative excision usuallyconstitutes adequate treatment. Recurrences have beendescribed, but metastases are exceptionally rare [113].There are no histological features predicting more aggressivebehaviour [9].References1. Abdelsayed RA, Eversole LR, Singh BS, Scarbrough FE (2001)Gigantiform cementoma: clinicopathologic presentation of 3cases. Oral Surg Oral Med Oral Pathol Oral Radiol Endod91:438–4442. Altini M, Thompson SH, Lownie JF, Berezowski BB (1985)Ameloblastic sarcoma of the mandible. J Oral MaxillofacSurg 43:789–7943. Ameerally P, McGurk M, Shaheen O (1996) Atypical ameloblastoma:report of 3 cases and a review of the literature. Br JOral Maxillofac Surg 34:235–2394. Auclair PL, Cuenin P, Kratochvil FJ, Slater LJ, Ellis GL (1988)A clinical and histomorphologic comparison of the centralgiant cell granuloma and the giant cell tumor. Oral Surg OralMed Oral Pathol 66:197–2085. August M, Faquin W, Troulis M, Kaban L (2003) Clear cellodontogenic carcinoma. Evaluation of reported cases. J OralMaxillofac Surg 61:580–6856. Baden E, Moskow BS, Moskow R (1968) Odontogenic gingivalepithelial hamartoma. J Oral Surg 26:702–7147. Badger JV, Gardner DG (1997) The relationship of adamantinomatouscraniopharyngioma to ghost cell ameloblastomaof the jaws: a histopathologic and immunohistochemicalstudy. J Oral Pathol Med 26:349–3558. Barker BF (1999) Odontogenic myxoma. Semin Diagn Pathol16:297–3019. Barrett AW, Morgan M, Ramsay AD, Farthing PM, NewmanL, Speight PM (2002) A clinicopathologic and immunohistochemicalanalysis of melanotic neuroectodermal tumor ofinfancy. Oral Surg Oral Med Oral Pathol Oral Radiol Endod93:688–69810. Barron RP, Kainulainen VT, Forrest CR, Krafchik B, MockD, Sandor GKB (2002) Tuberous sclerosis: clinicopathologicfeatures and review of the literature. J Craniomaxillofac Surg30:361–36611. Brannon RB (1976) The odontogenic keratocyst. A clinicopathologicstudy of 312 cases. I. Clinical features. Oral SurgOral Med Oral Pathol 42:54–7212. Brannon RB (1977) The odontogenic keratocyst. A clinicopathologicstudy of 312 cases. II. Histopathologic features.Oral Surg Oral Med Oral Pathol 43:233–25513. Brannon RB, Fowler CB (2001) Benign fibro-osseous lesions:a review of current concepts. Adv Anat Pathol 8:126–14314. Brannon RB, Fowler CB, Carpenter WM, Corio RL (2002)Cementoblastoma: an innocuous neoplasm? A clinicopathologicstudy of 44 cases and review of the literature with spe-