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.