AN UNUSUAL INFRATENTORIAL TUMOR: A CEREBELLAR DNET CASE REPORT
A 21 years old female patient was presented to the ER with severe, episodic frontal headaches associated with nausea, vomiting and difficulties with balance. Magnetic Resonance (MR) images of the brain without and with Gadolinium administration depicted a focal lesion located at the medial margin of the left cerebellum, measuring 1.6 x 1.2 x 1.6 cm in anterior posterior, transverse and craniocaudal diameters respectively. This lesion was T1 hypointense, T2 hyperintense and with mixed signal behavior on FLAIR images suggesting cystic degeneration. There was no appreciable enhancement on post gadolinium T1 images. There was no evidence of diffusion abnormalities or restriction in the apparent diffusion coefficient (ADC) map. The initial diagnostic impression by imaging findings favored an atypical pilocytic astrocytoma versus a low-grade diffuse fibrillary astrocytoma. Patient was scheduled for the tumor resection. After getting a localizing MR scan, she was taken to the operating room. The tumor was resected and hemostasis was assured. The surgical cavity was filled up with an absorbable hemostat material, the dura was closed and a cranioplasty was performed. The specimen received for intraoperative consultation and subsequent examination was fragmented, soft and gelatinous. The histologic features and immunophenotype were characteristic of dysembryoplastic neuroepithelial tumor. Clinical outcome was favorable and uncomplicated. The patient was discharged from hospital three days after surgery. The current report highlights the need to consider this entity in the differential diagnosis of infratentorial neoplasms.