Medulloblastoma, desmoplastic

CLINICAL HISTORY:
A 34-year old female patient complains of progressive gait instability and a tendency to fall. She suffers from increasing headaches and diminished visual acuity.

NEUROLOGICAL EXAMINATION reveals bilateral papilledema. Besides the gait instability with positive Romberg test there are no other neurological signs.

MRI:
a) TRANSAXIAL T2-WEIGHTED SPIN-ECHO (5400/119/1) SEQUENCE (IMAGE 1) shows a mass lesion in the midline in the posterior fossa, located in the superior vermis. Anterior displacement of the fourth ventricle is noted (arrowheads). Some cystic components can be seen posteriorly.

b) TRANSAXIAL T1 WEIGHTED SPIN-ECHO (600/14/1) SEQUENCE (IMAGE 2): The mass is hypointense.

c) TRANSAXIAL (IMAGE 3), CORONAL (IMAGE 4) AND SAGITTAL (IMAGES 5 AND 6) GADOLINIUM-ENHANCED T1-WEIGHTED SPIN-ECHO SEQUENCES show overall intense enhancement of the tumor, with confirmation of the small cystic components. In this multiplanar imaging, the multilobulated appearance of the tumor becomes evident. The tumor abuts the undersurface of the tentorium and extends towards the hiatus tentorii (arrowheads). The aqueduct and fourth ventricle (arrows) are anteriorly and inferiorly displaced.

RADIOLOGICAL DIFFERENTIAL DIAGNOSIS includes an atypical meningioma, possibly arising from the tentorium, hemangiopericytoma, pilocytic astrocytoma or metastasis.

SURGICAL INTERVENTION was performed via suboccipital craniotomy. The tumor appeared to originate from the superior vermis and was moderately vascular with a soft consistency. The lesion reached up to the incisura. Total resection was possible. Treatment was completed with craniospinal radiotherapy.

ANATOMOPATHOLOGICAL EXAMINATION (IMAGE 7) was consistent with desmoplastic medulloblastoma.

FOLLOW-UP: Eight months after treatment the patient is doing well.

Search also:
Medulloblastoma

The ESNR CD-Rom Series