Multiple endocrine neoplasia type two B. A case report with light and electron microscopic and immunohistochemical correlation

PURPOSE: To describe a case of multiple endocrine neoplasia type two B (MEN IIB) where ocular and systemic clinicopathological findings are correlated, in association with light and electron microscopic and immunohistochemical findings. METHODS: A 23-year-old man presented with mucosal neuromas of the lips, tongue and eyelids, a Marfanoid habitus and prominent corneal nerves. These findings led to the diagnosis of multiple endocrine neoplasia type two B. The patient subsequently developed phaeochromocytoma and metastatic medullary thyroid carcinoma (MTC) which led to his demise. Correlation of light and electron microscopic and immunohistochemical findings with the systemic and ocular findings is presented to emphasise the aggressiveness of MTC in MEN IIB. Clinicopathological correlation was obtained by examining the eyes post mortem. RESULTS AND CONCLUSIONS: Three new findings in MEN IIB have been established by this study. The enlarged corneal nerves can now be regarded as ganglioneuromas. Medullary thyroid carcinoma metastases were found in the choroid. Light and electron microscopic examination of the eye showed ganglioneuromas of the nerves in the limbus, trabecular meshwork, uveal tract and posterior ciliary nerves; this finding may account for the glaucoma occasionally seen in patients with MEN IIB.