Familial papillary thyroid microcarcinoma: a new clinical entity

BACKGROUND: Familial, non-medullary thyroid carcinoma is clinically more aggressive than the sporadic form. We wanted to find out whether papillary thyroid microcarcinoma also occurs in a familial pattern, and, if so, to identify specific clinical and prognostic features. METHODS: We reviewed the clinical records of 119 patients with papillary thyroid microcarcinoma. Familial occurrence, together with clinical presentation, surgical treatment, pathological characteristics, and follow-up were recorded. FINDINGS: We identified a family history of thyroid carcinoma in seven patients. The tumour was multifocal in five patients, bilateral in three, and vascular invasion occurred in three of the seven patients. Lymph-node metastases were found in four patients. Three patients had a recurrence and one patient with pulmonary metastases died within 11 months. INTERPRETATION: We identified familial occurrence in 5.9% of cases of papillary thyroid microcarcinoma. The unfavourable behaviour in the familial form of papillary thyroid microcarcinoma suggests that radical treatment and careful follow-up are warranted.