Primary ependymoma of the fallopian tube: a case report

Abstract

Synopsis: Ependymomas arise generally from ependymal cells covering the ventricles and central canal of the spinal cord, but rarely occur outside the central nervous system (CNS). In the field of gynecology, ovarian ependymomas are the most commonly reported, while primary cases of the fallopian tube have not been reported. In this report, we describe a case of primary ependymoma of the left fallopian tube that was discovered accidentally during histopathological examination of a specimen obtained after laparoscopic surgery for uterine adenomyosis and endometriotic cyst. A 42-year-old woman underwent laparoscopic total hysterectomy and bilateral adnexectomy. Histopathology revealed a 9 mm diameter neoplastic lesion with perivascular pseudorosette and ependymal rosette in the lumen of the ampulla of the left fallopian tube. Immunohistochemical staining was positive for GFAP, EMA, CK7, PAX-8, WT1, estrogen and progesterone receptors. S-100, CK20, CD10 and p53 were negative. Based on these findings and the absence of other neoplastic lesions on brain MRI and FDG-PET CT, the diagnosis of primary ependymoma of the fallopian tube was made. The patient has remained disease-free for 11 years. If diagnosis of extra-CNS ependymomas is difficult because they show a variety of histologic structures in addition to the rosette structure, GFAP-positive finding is useful.