Ganglioglioma in mature cystic teratoma of the ovary: Case report and review of the literature.

Introduction: Ganglioglioma of the ovary is a rare neuroectodermal-type tumor, morphologically like its counterparts in the central nervous system, and only two cases have been reported before. Case report: The patient, a 30-year-old woman with no prior medical history of brain tumors or neurological disorders, was found to have a cystic mass in the left ovary, accompanied by two mural nodules. Histologically, the mural nodule in the teratoma exhibited a combination of neoplastic ganglion and glial cells. Notably, the ganglion cells exhibited binucleation and focal distribution, with the occasional presence of Nissl bodies. Immunohistochemically, GFAP and Olig2 were positive in glial cells, chromogranin A (CgA), Nestin, CD34, Neu-N, and Calretinin (CR) were positive in ganglion cells. The tumor cells demonstrated a low Ki67 index, harbored a wild-type P53 expression and were negative for IDH1 and BRAF V600E. The patient underwent laparoscopic resection of the left ovary and fallopian tube and she was in good condition at 12 months follow-up. Conclusions: Ganglioglioma arising in mature cystic teratoma of the ovary is an extremely rare tumor. The description of cases is crucial for making the correct diagnosis and developing an effective treatment strategy for pathologists and clinical doctors.