Signet ring cell variant of follicular thyroid carcinoma: Report of two cases with focus on morphological, expressional and genetic characteristics.

The SRC-FTCs described herein were small, TERT promoter wildtype tumors exhibiting low proliferation, thereby suggesting that these exceedingly rare lesions probably carry a favorable prognosis - although the scarce availability regarding descriptions of this tumor entity nevertheless might justify careful clinical monitoring and mandate investigations in larger case series.