A case of multiple endocrine neoplasia type II b with nasopalatine cyst

Multiple endocrine neoplasia (MEN) type II b is a syndrome associated with medullary thyroid carcinoma, phenochromocytoma, and multiple mucosal neuromas. We encountered a rare case of MEN type II b with a palatal cyst and an impacted supernumerary tooth. A 46-year-old man presented to Okazaki municipal hospital because of pain of the palate. He had bumpy lips, multiple diffuse tumors of the oral mucosa, and an open bite. After operation for the palatal cyst, the blood pressure fluctuated widely, ranging from 110/70 to 300/160mmHg. Further examination revealed that he had phenochromocytoma and medullary thyroid carcinoma with lymph node metastases. The palatal cyst was a nasopalatine duct cyst with an impacted supernumerary tooth. Multiple mucosal tumors were diagnosed as neuromas on examination of biopsy specimens.