Extraventricular neurocytoma of the sellar region: report of two cases and literature review

Extraventricular neurocytoma (EVN) of the sellar region is a rare occurrence. To date, merely two reports concerning this tumor have been reported. In this report, we present two cases of EVN that occurred in the sellar region, and reviewed the pathological characteristics and treatment strategies for this disease. Two patients were admitted to our hospital for impaired vision. MRI scans indicated an enhanced invasive mass in the sellar region. One patient was treated via the subfrontal approach, and partial removal was achieved. The other patient was treated via the transsphenoidal approach by microscopy, and subtotal removal was achieved. Histologically, the tumor demonstrated typical features of neurocytoma, which presented nests, islands and strands of neuropil background. Immunohistochemistry (IHC) revealed diffuse Synaptophysin, MAP-2 and neurofilament positivity. Patients were diagnosed with EVN (WHO grade II) and adjuvant radiotherapy was given. In the present report, no loss of 1p/19q or atypical pathological feature was found. Furthermore, some of the molecular pathological characteristics of EVN were explored by literature review. Through these two cases, we confirm that EVN of the sellar region shares similar clinical pathological features with EVN of the other regions. Immunohistochemical examination is an effective method for the diagnosis of EVN. The preferred treatment for EVN of the sellar region is total removal by surgical approaches. Postoperative radiotherapy should be performed for tumors with atypical pathological features or when complete removal is not achieved.