Clinical curiosity: cribriform-morular variant of papillary thyroid carcinoma

BACKGROUND: There is an increasing awareness of the association of papillary thyroid carcinoma and familial adenomatous polyposis (FAP). Although the incidence is rare, most tend to occur in women. Several authors have described a distinctive histologic variant of papillary thyroid carcinoma, the cribriform-morular variant, which is associated with FAP but also may be encountered in patients with non-FAP. This diagnosis may precede the symptoms of colorectal polyposis. METHODS: A healthy 36-year-old woman was seen with a left thyroid nodule, and a 34-year-old woman with FAP was seen with a right thyroid nodule; both masses were suspicious for papillary thyroid carcinoma. Both patients underwent total thyroidectomy. RESULTS: Pathologic examination of both specimens revealed papillary thyroid carcinoma, cribriform-morular variant. The first patient subsequently underwent colonoscopy, which was negative for polyposis. CONCLUSIONS: Patients diagnosed with the cribriform-morular variant of papillary thyroid cancer should be screened for the presence of FAP.