Giant cell glioblastoma with lipogenic differentiation in a patient with neurofibromatosis type 1: A case report

Abstract

A 45‐year‐old woman with neurofibromatosis type 1 (NF1) developed a tumor in the left frontal lobe that showed features of giant cell glioblastoma (GC‐GB). In addition to the typical GC‐GB features, the tumor showed lipogenic differentiation, with many atypical lipoblasts and mature adipocytes. Tumor cells, including the lipogenic cells, were immunoreactive for GFAP, S‐100 protein, ATRX, and p53. They were negative for IDH1‐R132H, BRAF V600E, synaptophysin, NeuN, p16, mismatch repair proteins, and CD34. The patient is free from recurrence at approximately two years postoperatively. This is the fifth reported case of NF1‐associated GC‐GB (the second adult case). NF1 gene mutation might have played a role in the pathogenesis of lipogenic differentiation of GC‐GB. The differential diagnosis of lipidized GC‐GB from gliosarcoma or anaplastic pleomorphic xanthoastrocytoma is briefly discussed.