Abstract. Olfactory ensheathing cell tumor (OECT) is one of the most rare intracranial, extra-axial tumors located in the anterior cranial fossa. The present study reports a case of a 34-year-old female patient who presented with a history of hyposmia for 1 year, as well as a gradual dizziness and emotional lability for 2 months. Magnetic resonance imaging of the brain revealed a globose, well-defined cystic mass at the midline of the anterior cranial fossa, which was confirmed as an OECT by histology and was completely resected by bifrontal craniotomy. According to the immunostaining results, the tumor was positive for vimentin and S100 protein, and negative for epithelial membrane antigen, glial fibrillary acidic protein and cluster of differentiation 57 (also known as Leu-7). The presentation, imaging findings, histopathological examination and histogenesis of OECT are discussed in the present study, along with a literature review.

Abstract. Magnetic resonance imaging (MRI) is the most widely discussed and clinically employed method for the differential diagnosis of oligodendrogliomas; however, MRI occasionally produces unclear results that can hinder a definitive oligodendroglioma diagnosis. The present study describes the case of a 34-year-old man that suffered from headache and right upper-extremity weakness for 2 months. Based on the presurgical evaluation, it was suggested that the patient had a World Health Organization (WHO) grade II-II glioma, meningioma or arteriovenous malformation (AVM), with unclear radiological manifestations. Postsurgical pathological assessment confirmed the tumor to be an anaplastic oligodendroglioma (WHO grade Ⅲ). This case is notable due to the confusing radiological manifestation of a mushroom-shaped anaplastic oligodendroglioma in the parietal-temporal-occipital region, which provided a potential source of misdiagnosis for meningioma and AVM.