A case of ovarian Sertoli-Leydig cell tumor with high grade transformation harbouring DICER1 and TP53 mutations

Sertoli-Leydig cell tumor (SLCT) is a rare ovarian sex cord-stromal tumor that may occur sporadically or in the context of DICER1 syndrome. We present a case of ovarian SLCT with high-grade transformation in a 73-year-old patient. The tumor showed typical morphology and immunophenotype of moderately differentiated SLCT with distinct areas of high-grade transformation. NGS DNA sequencing revealed two somatic DICER1 mutations. In addition, a pathogenic TP53 mutation was detected exclusively in the high-grade area. This case represents only the second documented ovarian SLCT with confirmed high-grade transformation supported by a concurrent TP53 alteration.