Thyroid Microcalcifications in the Absence of Identifiable Nodules and Their Association With Thyroid Cancer

Objectives To determine ultrasound (US) and clinical findings of thyroid microcalcifications in the absence of a nodule and their association with the risk of malignancy. Methods The Institutional Review Board approved a 5‐year retrospective study. Twenty‐one patients with clustered or scattered thyroid microcalcifications in the absence of nodules on US images who underwent fine‐needle aspiration biopsies (FNABs) were included. Demographic and clinical data, US findings, and pathologic results were registered. Patients with a suspicion of malignancy or papillary thyroid carcinoma (PTC) on FNAB underwent thyroidectomy. Patients with benign results on FNAB underwent clinical and US surveillance. Results The mean age of the 21 patients was 33.2 years (29.5 years in patients with PTC patients and 39.4 years in those with benign findings; P = .034). Eleven of 21 patients had clustered microcalcifications (9 had cancer), and 10 of 21 patients had scattered microcalcifications (4 of 10 had cancer; P = 0.063). Sixty‐two percent of the patients had FNAB findings that were suspicious for cancer or had a diagnosis of cancer. Eleven of 13 patients had surgical thyroidectomy performed in our institution; in all cases, Hashimoto thyroiditis was confirmed. Univariate and multivariate analysis showed that only age was significant (odds ratio, 0.9; P < .05). Conclusions Our study suggests that the presence of thyroid microcalcifications without a nodule is suspicious for PTC. We found that both patterns were suspicious for PTC, particularly in young patients. Special concern arises for those clustered microcalcifications on a background of Hashimoto thyroiditis.