Adult medulloblastoma: a case report

Abstract

Background: Medulloblastoma is a malignant brain tumor that is common in children but very uncommon in adults, especially those older than 40 years, accounting for less than 1% of all primary brain tumors in adults. Although surgery and radiotherapy play an important role treatment of adult medulloblastoma, the use of chemotherapy is controversial. This is the first instance of adult medulloblastoma at the Ocean Road Cancer Institute in Tanzania.

Case description: We report the case of a 51-year-old female of African ethnicity who was diagnosed with high-risk hemispheric posterior cranial fossa medulloblastoma of classic type with World Health Organization central nervous system grade 4 and Chang stage M0. Immunohistochemistry, reticulin stain, and molecular subtyping could not be done because they were not available. She was treated by subtotal posterior cranial fossa tumor resection followed by adjuvant concurrent chemo-craniospinal radiation and adjuvant chemotherapy.

Conclusion: Even in adults over 50 years old, medulloblastoma should be included in the differential diagnosis of posterior fossa tumor. Adult medulloblastoma is a very rare and very heterogeneous tumor, but it has a good prognosis. Immunohistochemistry and molecular subclustering are difficult to implement in low-income countries such as Tanzania owing to cost. Treatment of adult medulloblastoma is highly heterogeneous among (and even within) facilities. There is no evidence that the extent of resection enhances survival. While craniospinal radiation therapy improves survival, there is controversy about the role of chemotherapy in managing adult MB.

Keywords: Case report; Chemotherapy; Craniospinal radiation; Medulloblastoma; Ocean Road Cancer Institute; Posterior cranial fossa.

Fig. 1

A timeline of important events

Fig. 2

T1W image showing hypointense left lateral posterior cranial fossa lesion as indicated by the arrow

Fig. 3

Diffuse and solid sheets with focal areas of nodularity, but desmoplasia was not evident

Fig. 4

Small round cells with dense nuclear chromatin, scant and indistinct cytoplasm

Fig. 5

Whole-brain lateral fields

Fig. 6

Posterior radiotherapy field to the spinal cord

Fig. 7

T1W brain MRI 9 months after finishing treatment showing a significant reduction in the posterior cranial fossa lesion as indicated by the arrow