We wanted to analyze the peripheral calcification patterns of thyroid tumors that were seen on ultrasound and we also wanted to evaluate the clinical usefulness of the peripheral calcifications of the thyroid tumors.

We retrospectively analyzed 21 peripheral calcifications of the thyroid tumors of 18 patients; these were histopathologically confirmed by fine needle aspiration biopsy, automated gun biopsy and surgery. The peripheral calcification patterns were categorized into three types: type 1, peripheral nodular calcification, type 2, peripheral smooth rim calcification, and type 3, peripheral irregular rim calcification. The histopathologic results obtained during surgery, fine needle aspiration or automated gun biopsy were compared.

Of the total 21 peripheral calcifications of thyroid tumors, 5 cases showed as being type 1 (24%), 3 cases showed as being type 2 (14%) and 13 cases showed as being type 3 (62%). Of the total 21 peripheral calcifications of the thyroid tumors, 18 were histopathologically confirmed as papillary carcinoma (86%). Among the type 1 peripheral calcification patterns, 3 cases were coincidentally diagnosed as papillary carcinoma and 2 cases were follicular neoplasm on the preoperative biopsy results and on the surgical results. Two cases of type 2 peripheral calcifications (67%) and three cases of type 3 peripheral calcifications (23%) were diagnosed as benign lesions upon preoperative biopsy, but the postoperative results were papillary carcinoma.

Peripheral calcifications of thyroid tumors are important feature that suggest malignancy together with the microcalcification and peripheral calcifications of the type 2 and type 3 patterns, and these lesions may be difficult to accurately diagnose with using only biopsy.