Brain Pathology Case of the Month - March 2008

Contributed by: Priya Banerjee, MD and Barbara Crain, MD PhD
Johns Hopkins Hospital, Department of Pathology


CLINICAL HISTORY:

A previously healthy 2-year-old child first presented with a new limp and mild weakness of her right leg. Initial workup with x-rays was negative. Her condition worsened over two weeks with new neurological deficits including worsening gait changes resulting in crawling rather than walking and holding her right arm in a flexed position. MRI (T1 with contrast) showed a large solid and cystic intra-axial mass with markedly heterogeneous enhancement centered within the frontoparietal region with extension into and expansion of the body of the corpus callosum (Figures 1 and 2). Stereotactic biopsy for diagnosis and surgical decompression was performed. She was treated with steroids and anticonvulsants. Further chemotherapeutic treatment was scheduled, but she continued to worsen with lethargy and hypertonicity requiring hospitalization. She clinically deteriorated with unreactive pupils and cerebral posturing. MRI showed tumor progression with herniation. She expired three months after onset of her symptoms. A brain only autopsy was performed.

GROSS DESCRIPTION:

Autopsy showed a markedly edematous brain weighing 1550 g fresh (fresh average weight 2 year old brain 1064 g) with generalized flattening of the sulci and gyri. There was destruction and softening of the right temporal lobe consistent with uncal herniation. Serial coronal sections of the cerebral hemispheres revealed a soft, hemorrhagic, gelatinous tumor maximally measuring 11 cm anterior to posterior, involving both hemispheres, crossing the corpus callosum, involving both caudate nuclei and completely effacing both lateral ventricles. The thalamus and putamen were grossly spared. There was a generalized midline shift to the left (Figure 3).

MICROSCOPIC DESCRIPTION:

Histologic examination of the tumor revealed pleomorphic, hyperchromatic tumor cells with prominent nucleoli. There was no inflammatory infiltrate. The tumor displayed a mix of hypocellular and hypercellular areas (Figures 4 and 5 respectively) with prominent Alcian blue staining in many of the hypocellular areas (Figure 6). Focal necrosis with surrounding pseudopalisading of tumor (Figure 7) and focal vascular proliferation (Figure 8) were identified. The tumor cells were immunoreactive for glial fibrillary acidic protein (GFAP) (Figure 9). Ki67 immunostaining demonstrated a high proliferation rate (Figure 10).

FINAL DIAGNOSIS


International Society of Neuropathology