Diffuse microcalcifications only of the thyroid gland seen on ultrasound: Clinical implication and diagnostic approach

Background: To evaluate the clinical implications and diagnostic approach of lesions showing only diffuse microcalcifications on thyroid ultrasound (US). Methods: From January 2004 to January 2011, a total of 31 patients had lesions showing diffuse microcalcifications alone on thyroid US. Among them, 26 patients (M:F ratio 4:22; mean age 37.5 years, range 15-56 years) who had underwent US-guided fine-needle aspiration biopsy (US-FNAB), subsequent surgery, or follow-up US after 1 year after initial US-FNAB were included. Histopathologic results from surgery or US-FNAB were considered as standard reference. Clinical and US features were compared to standard reference. Results: Of the disease of 26 patients, 16 (61.5%) were diagnosed as malignancy and 10 (38.5%) as benign. Seventeen (65.4%) of the 26 patients included were diagnosed as having Hashimoto thyroiditis (HT) on a clinical basis. Eight (80.0%) of the 10 benign lesions were diagnosed as benign on initial US-FNAB, and the remaining 2 lesions (20.0%) were nondiagnostic. All malignant lesions were diagnosed as suspicious for papillary thyroid carcinoma (PTC) or PTC by US-FNAB. Of the US features, presence of pathologic lymph nodes were significantly higher in malignant disease compared to benign findings, 10 (62.5%) to 0 (0.0%) (P = 0.003). Conclusions: Diffuse microcalcifications only lesions of the thyroid show high prevalence of PTC and lymphocytic thyroiditis. US-FNAB shows an acceptable performance in lesions showing microcalcifications only on thyroid US.