NF2 and ATRX gene copy number losses on a case of ovarian ependymoma.

Ovarian ependymomas are rare glial neoplasms that typically occur in women on their third to fourth decades of life. They are histologically similar to ependymomas of the central nervous system but may have a broader immunophenotype. We describe a 27-year-old woman who presented to the emergency department with a 3-week history of cough and shortness of breath. Further workup disclosed a left pelvic mass and extensive intra-abdominal metastases. Pathology revealed sheets of monomorphic cells within a fibrillary stroma, papillary projections, true ependymal rosettes, and pseudorosettes consistent with an ependymoma of ovarian origin. Next-generation sequencing showed ATRX and NF2 copy number losses. Fluorescence in situ hybridization for EWSR1 demonstrated monosomy of 22q in greater than 90% of cells. These molecular alterations have not been previously reported in ovarian or extra-central nervous system ependymomas.