Synchronous presentation of prolactinoma and supratentorial tanycytic ependymoma

Abstract

Tanycytic ependymomas mostly occur in the spinal cord and it is the rarest histological subtype of ependymoma. A 29-year-old male was referred from the infertility clinic after serum prolactin levels were found to be elevated. Magnetic resonance imaging (MRI) brain showed an irregular necrotic lesion in the periventricular region of the left parietal lobe which had an intraventricular component and associated perilesional edema. In addition, a sellar mass with suprasellar extension was also found on the MRI. He was started on cabergoline therapy for macroprolactinoma and underwent a left parietal craniotomy, and microsurgical excision of the tumor using intraoperative neurosonographic guidance. Histologically, the tumor showed spindle cytologic features and poorly developed inconspicuous pseudorosettes, with areas of rounded nuclear profiles and perinuclear cytoplasmic clearing. Tumor cells were positive for vimentin, glial fibrillary acidic protein and S100, and negative for epithelial membrane antigen. Ki67 was <7%. He was diagnosed with tanycytic ependymoma and a coexistent prolactinoma. He received 10 cycles of image-guided radiotherapy. Post-operative imaging showed minimal residual tumor the size of which remained stable at 1-year follow-up scan. The pituitary macroadenoma regressed with cabergoline therapy and he clinically improved. This presentation of synchronous macroprolactinoma and tanycytic ependymoma has not been reported in the literature previously. An exhaustive literature review showed only 18 previously reported cases of supratentorial tanycytic ependymoma.