title: Neural hyperplasia in maxillary bone of multiple endocrine neoplasia type 2B patient.
abstract: Multiple endocrine neoplasia (MEN) type 2B is the rarest and most aggressive form of MEN syndrome. MEN 2B patients manifest characteristic oral and facial features besides the neural crest cell-derived tumors, including medullary carcinoma, pheochromocytoma, mucosal neuroma, and ganglioneuromatosis of the gut. We report a case of MEN 2B diagnosed on the basis of the warning signs of mucosal neuroma and multiple neural hyperplasias in the maxillary bone resected during orthognathic surgery. A subsequent systemic examination under the pathologic diagnosis of neural lesions revealed medullary thyroid carcinoma, megacolon, thickened corneal nerves, and RET gene mutation, thus verifying the diagnosis of MEN 2B. An immunohistochemical study revealed an increased number of unmyelinated Schwann cells in the hyperplastic nerves. We suggest that intraosseous neural hyperplasia is a specific finding of the MEN 2B syndrome in addition to the known oral and facial manifestations.
authors.affiliation: Clinical Laboratory, Osaka University Dental Hospital, Osaka, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Usami
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Takenobu
authors.forename: Risa
authors.initials: R
authors.lastname: Kurihara
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Imai
authors.forename: Shogo
authors.initials: S
authors.lastname: Shinohara
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Fukuda
authors.forename: Satoru
authors.initials: S
authors.lastname: Toyosawa
mesh_terms: D000293:Adolescent; D019943:Amino Acid Substitution; D018276:Carcinoma, Medullary / Q000473:pathology / Q000556:secondary; D003062:Codon / Q000235:genetics; D003315:Cornea / Q000294:innervation; D005091:Exons / Q000235:genetics; D006801:Humans; D006965:Hyperplasia; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D008437:Maxilla / Q000294:innervation*; D008531:Megacolon / Q000473:pathology; D008715:Methionine / Q000235:genetics; D009062:Mouth Neoplasms / Q000473:pathology*; D018814:Multiple Endocrine Neoplasia Type 2b / Q000473:pathology*; D009154:Mutation / Q000235:genetics; D009463:Neuroma / Q000473:pathology*; D024343:Open Bite / Q000601:surgery; D019340:Osteotomy, Le Fort / Q000379:methods; D051096:Proto-Oncogene Proteins c-ret / Q000235:genetics; D012583:Schwann Cells / Q000473:pathology; D013912:Threonine / Q000235:genetics; D013964:Thyroid Neoplasms / Q000473:pathology
chemical_list: D003062:Codon; D013912:Threonine; D008715:Methionine; D051096:Proto-Oncogene Proteins c-ret; C099282:RET protein, human