Multiple endocrine neoplasia type 2b associated with lichen nitidus.

Multiple endocrine neoplasia (MEN) type 2B syndrome is an autosomal dominantly inherited endocrine disorder with rare skin manifestations. We report the case of a 19-year-old Turkish girl who presented with skin-colored flat papules scattered all over the trunk and extremities. Additionally, she had marfanoid habitus, thick lips, and multiple flesh-colored papules over the inner eyelids and oral mucosa. Histopathological examination of one of the trunk lesions was consistent with lichen nitidus. Her past medical history was significant for medullary thyroid carcinoma. Genetic testing showed a point mutation in exon 16 at codon 918 (M918T) in the RET proto-oncogene. Based on all these findings, MEN type 2B was diagnosed. To the best of our knowledge we report the first case of MEN type 2B associated with lichen nitidus.