393- What are the mucosal neuromas?
Neuromas are encapsulated nerve sheath tumors which are composed of well-
differentiated Schwann cell, while neurofibromas are unencapsulated fusiform
nerve sheath tumors which are composed of Schwann cell, perineural cell, and
fibroblast in a collagen matrix. The neuromas in MEN2B are present on muco-
sal surfaces including dorsal surface of the tongue, palate, and pharynx and
along with the whole digestive tract. Neuromas of the eyelids may cause thick-
ening and eversion of upper eyelid margins, and thickened corneal nerves may
be seen by slit lamp examination. Neuromas of the lips give a typical blubbery
lip appearance (Fig. 11.6), and palpable submucosal nodules may be present at
vermilion border of the lip. Mucosal neuromas are present in almost in all
patients with MEN2B syndrome. Approximately, 80 % of the individuals may
have gastrointestinal symptoms even during infancy due to diffuse
ganglioneuromatosis.a bFig. 11.5 (a) A 16-year-old boy presented with multiple mucosal neuromas, medullary thyroid
carcinoma, and (b) bilateral asymmetrical pheochromocytoma (red arrows)
11 Multiple Endocrine Neoplasia