Multiple Endocrine Neoplasia 2B (Men 2B)/Men 3

Multiple palisaded encapsulated neuromas in a child without other associated abnormalities

“…Cutaneous neuromas are unusual in this syndrome. 3 Mutations in the RET protooncogene, a tyronise kinase receptor important for transmission of signals for cellular growth and differentiation, have been identified as the cause of MEN 2a and 2b syndromes. Specifically, mutations in exon 16, and rarely exon 15, in the RET protooncogene lead to the changes in MEN 2b.…”

“…MEN 2b is a particularly severe form of the MEN syndromes, and early recognition of mucosal neuromas would initiate early screening protocols for the potentially fatal cancers patients can develop. 3 Multiple neurofibromas are associated with neurofibromatosis, though patients can commonly have a solitary neurofibroma without any syndromic association. PENs do not seem to be increased in patients with neurofibromatosis.…”

Retroperitoneal ganglioneuroma: Report of a case diagnosed by fine-needle aspiration cytology, with review of the literature

“…6 Diffuse ganglioneuromatosis affecting any part of the gastrointestinal tract has also been described, 7,8 and may be associated with neurofibromatosis or the syndrome of multiple endocrine neoplasia (MEN) type IIb. 9 Composite pheochromocytoma/ganglioneuroma of the adrenal gland, associated with MEN IIa, has also been reported. 10 A rare case of solitary cutaneous ganglioneuroma has also been reported 11 which microscopically showed unmyelinated axons, Schwann cells, and scattered mature ganglion cells.…”

Mucocutaneous Neuromas

“…70,71 In addition to mucosal neuromas (typically involving the lips, tongue, and eyelids), MEN2B is characterized by aggressive medullary thyroid carcinomas, pheochromocytomas, gastrointestinal tract ganglioneuromatosis, corneal nerve hypertrophy, and a marfanoid body habitus. 72 Patients with MEN2B occasionally develop cutaneous neuromas, most often located in periorificial areas of the face. 73 However, cutaneous neuromas in acral sites or occurring in the absence of mucosal lesions have not yet been described in individuals with MEN2B.…”

“…10,14,15,32,44,72,84,85 On a molecular level, there is also considerable overlap in the signaling pathways regulated by PTEN and RET (Figure 3), especially those with important functions in controlling the growth and development of neural and neural crest-derived tissues. PTEN is a lipid phosphatase that serves as a central negative regulator of the phosphatidylinositol 3-kinase/Akt pathway, and proper PTEN signaling leads to G1 cell cycle arrest, apoptosis, or both.…”