LAUSR

A pregnant 23yearold woman presented during a gynecological ultrasound checkup with a 120×56×82 mm multilocular, nonechogenic, solid cystic left ovarian mass with a 12×33 mm internal papillary structure (Figure 1). High serum CA19.9 values were found (83 U/mL). CA125, carcinoembryonic antigen, and HE4 serum levels were within normal ranges. Evidence that the patient harbored a germline BRCA1 mutation (c.5266dupC–p.Gln1756Profs*74) prompted removal of the lesion after the pregnancy by a laparoscopic procedure with peritoneal/omental biopsies and peritoneal washing. Pathologically, the lesion consisted of heterogeneous tissues: epithelia, cartilage, mature bone tissue, and mature disorganized nervous tissue (Figure 2A). More cellular areas were composed of a proliferation of astrocytic elements with abundant dense eosinophilic cytoplasm (Figure 2B–C), being immunohistochemically positive for glial fibrillary acidic protein (GFAP) (Figure 2E), vimentin and S100. A second cell population showed dysplastic neuronal morphology (Figure 2D) and immunoreactivity for synaptophysin, chromogranin A, and neurofilament protein (Figure 2F). The pathological findings were consistent with a mature cystic teratoma associated with a ganglioglioma. Because BRAFV600E is one of the described mutations in gangliogliomas, BRAFV600E immunostaining was performed and was negative.