[A Case of Metachronous Multiple Thyroid Papillary Carcinoma with FAP]

Familial adenomatous polyposis (FAP) is an autosomal dominantly inherited disorder, the result of a germ line mutation in the adenomatous polyposis coli (APC) gene. FAP can be associated with various extracolonic lesions, including thyroid cancer, which frequently occurs in women. We report the case of a 36-year-old woman diagnosed as having FAP with multiple metachronous thyroid papillary carcinomas. She underwent left thyroidectomy at the age of 19 years without a diagnosis of FAP. Multiple polyps in her stomach were detected by medical examination and more than 100 polyps in the colon were found by colonoscopy. She was referred to our hospital after a diagnosis of non-profuse FAP. Multiple tumors with a maximum diameter of 10mm were detected in the right lobe of the thyroid gland during the preoperative examination. Papillary carcinoma was suspected based on fine-needle aspiration cytology. We performed a right thyroidectomy after prophylactic colectomy. Pathological findings revealed a cribriform-morula variant of papillary thyroid carcinoma. The patient remains well after 2 year 6 months with no recurrence.