A Rare Ovarian Mixed Sex Cord Stromal Tumor in a Patient with Ollier Disease: A Case Report.

This is a case report of a 10-year-old with Ollier disease and an ovarian mass. Ollier disease, a rare disorder characterized by multiple enchondromas resulting in bone deformities, has been occasionally associated with ovarian juvenile granulosa cell tumor. This patient developed signs of precocious puberty and was found to have an ovarian tumor; however, pathology revealed a mixed sex-cord stromal tumor with components of juvenile granulosa and Sertoli-Leydig cell tumor. Tumor genomic testing revealed an IDH1 mutation. Mixed sex-cord stromal tumors of this type, also called "gynandroblastomas," have been associated with DICER1 mutations and DICER1 tumor predisposition syndrome but never with Ollier disease. Our findings expand the known spectrum of syndromic associations with this tumor type, with implications for tumor screening.