Ovarian Sertoli-Leydig Cell Tumor with Predominant Heterologous Mucinous Differentiation and Foci of Hepatocytic Differentiation: Case Report and Review of The Literature

: Sertoli-Leydig cell tumor is a rare ovarian neoplasm and belongs to the group of sex cord stromal tumors. We present a case of a 15-year old girl diagnosed with Sertoli-Leydig cell tumor with heterologous elements consisting predominantly of mucinous epithelium and a sparse Sertoli-Leydig cell component, mimicking mucinous neoplasm. Furthermore, foci of hepatocytic differentiation were also identified. Immunohistochemical stains showed the component of Sertoli cell differentiation was positive for cytokeratin 18 and inhibin. The component of Leydig cell differentiation was strongly positive for inhibin. The component of hepatocytic differentiation was positive for low molecular weight keratin, HepPar1, alpha-fetoprotein and weakly positive for inhibin. Thus, this was a very rare case which created a challenge for pathologists, especially on frozen sections.