Adult cerebellar medulloblastoma: CT and MRI findings in eight cases

Abstract

-Medulloblastoma is a brain tumor of neuroepithelial origin, which represents 15 to 30% of all pediatric brain tumors, and less than 1% of CNS adult neoplasms. We report the imaging findings of 8 adult patients with medulloblastoma. The mean age was 35 years, ranging from 20 to 65 years, and the male:female rate was 3:5. The tumors were predominantly lateral (63%), hyperdense on CT scans (83%), and on the MRI, hypointense on T1 (100%) and hyperintense on T2 (80%) weighted images. It was seen intratumoral necrosis and cysts in six cases and calcifications in three. Hydrocephalus was observed in 5 cases and brain stem invasion in four. The imaging findings of medulloblastomas in adults are different of those in child, and also nonspecific. Although these tumors are uncommon in adults, they must be considered in the differential diagnosis of cerebellar masses in the posterior fossa of this age group.KEY WORDS: medulloblastoma, adults, computed tomography, magnetic resonance imaging.Meduloblastoma cerebelar em adultos: achados de TC e RM em oito casos Meduloblastoma cerebelar em adultos: achados de TC e RM em oito casos Meduloblastoma cerebelar em adultos: achados de TC e RM em oito casos Meduloblastoma cerebelar em adultos: achados de TC e RM em oito casos Meduloblastoma cerebelar em adultos: achados de TC e RM em oito casos RESUMO -O meduloblastoma é um tumor de origem neuroepitelial, que representa entre 15 e 30% dos tumores cerebrais em crianças e menos de 1% das neoplasias intracranianas em adultos. Apresentamos os achados de imagem de 8 pacientes adultos com meduloblastoma. A média de idade foi 35 anos, variando entre 20 e 65 anos, e a relação homem:mulher foi 3:5. Os tumores foram predominantemente laterais (63%), hiperdensos na tomografia computadorizada (83%), e, na ressonância magnética, hipointensos nas imagens ponderadas em T1 (100%) e hiperintensos nas ponderadas em T2 (80%). Necrose e cistos intratumorais foram observados em seis casos e calcificações em três. Cinco pacientes apresentavam hidrocefalia e quatro tinham invasão neoplásica do tronco cerebral. Os achados de imagem dos meduloblastomas em adultos são inespecíficos e diferentes daqueles que acometem crianças. Apesar destes tumores serem incomuns em adultos, eles devem sem considerados no diagnóstico diferencial de massas cerebelares na fossa posterior de pacientes neste grupo etário.

The Neuroradiological Spectra of Adult and Pediatric Medulloblastoma Differ

“…This will require a prospective study based on standardized scanning conditions. The finding of a decreased rate of contrast enhancement and differences of T1/T2 signals in MRI have been described previously by others [10,11,[25][26][27]; however, the patient numbers in these studies have never been sufficient to allow any definite conclusion. Our meta-analysis confirms that the differences seen in the T1/T2 phenotype and the pattern and amount of contrast enhancement are valid and relevant, although some uncertainty about the precise dimension remains.…”

“…In contrast, the typical MRI features of adults are vaguely defined. Retrospective case series suggest that a substantial proportion of adult medulloblastomas may differ from the typical phenotype seen in children [10,11]. Koci et al reported that the signal on T2 images was more variable [11] than in children [8].…”

Adult medulloblastoma mimicking Lhermitte-Duclos disease: Can diffusion weighted imaging help?

“…[7,8] The cerebellar location of medulloblastoma is between 50% and 63%. [7,9] The classical imaging appearance of medulloblastoma is that of a homogeneous midline vermian mass which shows uniform enhancement without any necrosis or cystic areas. While these features are seen more commonly in children, in adult tumor tends to be more heterogenous with cystic and necrotic areas.…”

Post‐delivery postural headache: not always a classical post‐dural puncture headache

“…Although most headaches tend to occur less frequently during pregnancy, new headaches may develop especially during the first and third trimesters (8). Medulloblastomas account for less than 1% of all adult brain tumours, and are mostly associated with vomiting in the morning and headache, symptoms frequently experienced during pregnancy (9).…”