Brain Pathology Case of the Month - December 2000

Contributed by Xuemo Fan, MD, PhD, Ted C Larson, MD, Mark T Jennings, MD, Noel B Tulipan MD, Steven A Toms, MD and Mahlon D Johnson*, MD, PhD
Department of Pathology, Division of Neuropathology (XF, MDJ), Department of Radiology (TCL), Neurology (MTJ) and Neurosurgery (NBT, SAT), Vanderbilt University Medical Center, Nashville, TN 37232, U.S.A.
Published on line in December 2000


CLINICAL HISTORY AND IMAGING:

This 6-month-old Caucasian boy presented with a 10-day history of progressive left head tilt, lethargy evolving into obtundation, deteriorating visual and motor skills. He has had no fever, seizures, chills, nausea or vomiting. Upon admission, CT and MR imaging of the head demonstrated a large right hemispheric mass with contrast enhancing solid (Fig 1, black arrow) as well as large cystic components (Fig 1, white arrows). A portion of the mass originated at the left ponto-mesocephalic junction, enwrapping the left 6th nerve (black curved arrow) and causing marked compression of the brainstem and obstruction of aqueduct of Sylvius with attendant hydrocephalus (Figure 1). Complete review of all MR imaging pulse sequences and imaging planes indicated the mass was both intra- and extra-axial, in part extending along the right tentorial leaflet and the superior margin of the temporal bone, exhibiting a dural tail, and traversing the right ambient, retrothalamic, and quadrigeminal plate cisterns. A regional mass effect with right uncal herniation was obvious as was marginating edema possibly containing neoplastic infiltration. T1-weighted contrast enhanced MR images helped distinguish solid from cystic components (Figure 1). T2-weighted MR images demonstrated hemosiderin staining (white curved arrow) within the mass representing chronic hemorrhagic breakdown products (Figure 2). No calcification was demonstrated on CT (not shown). He underwent craniotomy for a partial tumor resection and later a near total resection a week after initial resection. MR images two months later suggested progression of residual disease and treatment with carboplatin and vincristine was instituted.

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International Society of Neuropathology