Ovary, Sertoli-Leydig cell tumour

Sertoli-Leydig cell tumors of the ovary are very rare (less than 0.5% of ovarian neoplasms) with mean age of 25. Over 97% are unilateral. Patients with a germ line mutation of DICER-1 are often younger. Tumors are composed of varying proportion of Leydig and Sertoli cells. Sertoli cells form tubules (in well differentiated neoplasms) or cellular lobules consist of darkly staining cells with high N/C ratio (in moderately differentiated neoplasms). Leydig cells are seen admixed with Sertoli cells. Heterologous elements are seen in up to 20% of tumors. The most common heterologous elements are mucinous epithelium of enteric type. The prognosis is generally favorable and depends mostly on the grade.