Medulloblastoma in Adulthood

A 48-year-old man presented with a 1-month history of progressive unsteadiness when walking, dizziness, and intermittent headache. Clinical examination revealed cerebellar symptoms: left-sided dysmetry, dysdiadochokinesis, and gait ataxia. Magnetic resonance imaging (MRI) depicted a large, well demarcated, mass in the right cerebellar hemisphere with disruption of the blood–brain barrier and cerebrospinal fluid congestion. The surgical specimen showed a moderately pleomorphic, moderately proliferative small blue cell tumor, some segments of it with pseudorosette formation (Homer–Wright rosettes), pointing to neuroblastic tumor differentiation. Examination of aspirated cerebrospinal fluid and spinal MRI revealed no evidence of drop metastases. Taking the findings together, we diagnosed a histomorphologically classic WHO grade IV medulloblastoma, rarely found in adulthood. This diagnosis was confirmed by the Brain Tumor Reference Center in Bonn (Prof. Torsten Pietsch), and molecular pathology demonstrated SHH activation, TP53 wild type. This molecular subtype of medulloblastoma arises in the cerebellar hemisphere and has two peaks of occurrence in early childhood and adulthood. The prognosis after complete resection, irradiation of the neuraxis, concomitant chemotherapy, and maintenance therapy is much better than that of glioma (5-year survival rate 58–84% versus 20%).

Figure

Cranial MRI (T2 weighting)

Dr. med. Kathie Schmidt, Institut für Diagnostische und Interventionelle Neuroradiologie,
Georg-August-Universität Gottingen, [e-mail]

Dr. med. Simon Hametner, Klinisches Institut für Neurologie, Medizinische Universität Wien

Conflict of interest statement: The authors declare that no conflict of interest exists.

Translated from the original German by Christine Rye.

Cite this as: Schmidt K, Hametner S: Medulloblastoma in adulthood. Dtsch Arztebl Int 2020; 117: 792.
DOI: 10.3238/arztebl.2020.0792b