MATERIAL and METHODS: Adult patients (age>17 years) who had surgery in our clinic with the diagnosis of cerebellar mass between 2009 and 2015 and whose pathological diagnosis was medulloblastoma were examined. The study was carried out retrospectively by analyzing the clinicopathological data, surgical outcomes, and complications of the patients. In the postoperative and follow-up periods, contrast-enhanced cranial magnetic resonance imaging (MRI) was used to assess the presence of recurrence or residual disease. Moreover, the overall 5-year survival rates of the patients were evaluated.

RESULTS: A total of 16 patients were diagnosed with medulloblastoma, with a mean age of 32.25 years old (age range 18?57 years). The tumor was found in the vermis in eight (50%) patients and the cerebellar hemispheres in the rest (50%) of them. Total excision was performed on 14 (87.5%) patients, near-total excision on 1 (6.25%) patient, and subtotal excision on 1 (6.25%) patient. The histopathological results were consistent with desmoplastic type medulloblastoma in nine (56.25%) patients, classical type in six (37.5%) patients, and anaplastic medulloblastoma in one (6.25%) patient. All patients received posterior fossa boost dose + craniospinal radiotherapy after the surgery. Recurrent lesions were found in six (40%) of the patients. A total of ten (62.5%) patients were still alive, and mortality rate was found to be 25% (4 patients) at 5 years.

CONCLUSION: After 5 years, 10 of the 16 patients in our study were still alive. Lateral localization of the tumor, desmoplastic histologic variant, and total excision were all good prognostic indicators. Total excision is difficult in patients with brainstem invasion, and even if total excision is performed, the prognosis is poor. Keywords : Medulloblastoma, Adult, Desmoplastic, Adjuvant radiotherapy