A 22-year-old male presented to our department with a 3-months history of generalized headache, hearing loss, tinnitus and blurred vision. Physical examination of the patient revealed decreased visual acuity (right eye 20/80 and left eye one meter finger count), bilateral papillaedema, bilateral hearing loss and bilateral upward plantar responses. Other neurological examinations including muscle strength, sensory and gait were normal.
Brain magnetic resonance imaging (MRI) with and without contrast showed intense dural enhancement of cerebellar folia and cerebral convexity, moderate hydrocephalus and intraparenchymal signal changes in right cerebellar hemisphere (Figures 1 and 2).
Lumbar punctures were done three times that had negative results for gram stain, culture, Wright, angiotensin-converting enzyme, Indian ink, cerebrospinal fluid (CSF) adenosine deaminase, polymerase chain reaction for tuberculosis, CSF cytology and human immunodeficiency virus (HIV) antibody. CSF pressure was extremely high (about 70 cm H2O). CSF analysis showed normal cellular counts but elevated protein level and decrease glucose level was significant. Complete blood count, biochemistry profiles were normal. Erythrocyte sedimentation rate was 11 and C-reactive protein result was negative. Serum HIV antibody, HBs antigen, HCV antibody were all negative. Tuberculin purified protein derivative (PPD) was performed that had negative result. Serum Wright, ANA, ds DNA, Antineutrophil cytoplasmic antibody (cANCA and pANCA) and antiphospholipid antibody were within normal limits, too. Paranasal sinus, chest, pelvic and abdominal CT-Scan with contrast all had normal results. Audiometric evaluation showed bilateral asymmetrical sensory neural hearing loss.
A suboccipital craniotomy was performed and the posterior fossa dura, pia arachnoid and cerebellar hemispheres were subject to biopsy. Histological examination of biopsy material showed highly cellular neoplasm that is composed of cells with small to medium-sized, hyperchromatic nuclei and little apparent cytoplasm. Immunohistochemical stains performed on the biopsy material revealed positive reaction of tumor cells with neuron-specific enolase and glial fibrillary acidic protein and negative result with CD99. Synaptophysin shows weak positive reaction (Figure 3A-H).