Psammomatoid Calcification-Rich Oncocytic Thyroid Adenoma With Clear-Cell Change

Abundant calcifications and clear-cell change may occur in oncocytic thyroid adenoma (OTA). We aimed to report the features of a case of OTA peculiar by the presence of extensive calcifications and of a clear-cell component. The OTA was detected on a right thyroid lobectomy specimen. Clear-cell change was observed in 15%-20% of the cells. Numerous, focally confluent psammomatoid calcifications, resulting in macrocalcifications, were identified. The nodule cells, uni- or multinucleated oncocytes, including those with clear cytoplasm, expressed heterogeneously TTF1, S100 protein, Bcl2, CD10, as well as CD138 and CD56. Lipid-droplet markers adipophilin and TIP47 were also expressed. In conclus…