Multiple Mucosal Neuroma
A 9-year-old boy presented with a 6-year history of asymptomatic papules on his tongue, along with chronic constipation and abdominal discomfort since infancy. On physical examination, he was noted to have a marfanoid habitus, coarse facies, tooth malposition, and multiple soft, yellow papules measuring 3 to 12 mm on the tip of his tongue. Findings on histologic analysis of samples obtained from the tongue lesions were consistent with mucosal neuroma and supported the diagnosis of multiple endocrine neoplasia type 2B (MEN2B). Thyroid ultrasonography revealed two hyperechoic nodules. Computed tomography of the abdomen showed large colonic distention. Laboratory evaluation revealed a calcitonin level of 277 pg per milliliter (normal value, <10) and normal urinary and plasma levels of metanephrines. A de novo mutation in the gene encoding ret proto-oncogene (RET) was found. The patient underwent total thyroidectomy and nodal dissection that revealed bilateral medullary thyroid carcinoma with multiple metastatic lymph nodes. Rectal biopsy samples revealed intestinal ganglioneuromatosis. To date, the patient, whose disease is in remission, is under clinical surveillance with testing of serum calcitonin levels. Multiple lingual neuromas are suggestive of MEN2B and should prompt a careful evaluation for medullary thyroid carcinoma.
