Brain Pathology Case of the Month - March 2006

Contributed by Jorge E. Dotto1, Joachim Baehring2, Joseph M. Piepmeier2, Sergei I. Bannykh1
1Department of Pathology and 2Department of Neurosurgery, Yale-New Haven Hospital, New Haven, CT.


A 21-year-old female admitted to the hospital with severe headache. While driving, she suddenly could not feel the steering wheel in her right hand and experienced a feeling of getting lost. The symptoms subsided but followed by headache that gradually evolved into the worst headache in her life. Neurologic exam was normal and MRI imaging disclosed left parietal tumor with a large cystic component and enhancing mural nodule (Figure 1A). Differential diagnosis included ganglion cell tumor, PXA and pilocytic astrocytoma. The patient underwent left craniotomy with a complete resection of the tumor. Intraoperatively, the mass was intra-axial and consisted of a white-yellow firm 3 cm nodule located on a wall of a large cavity filled with an amber-colored fluid. There was no association with leptomeninges.


The biopsy specimen consisted of a solid yellow firm nodule, with an irregular granular surface and prominent superficial vasculature (Figure 1B). Microscopically, a non-infiltrative tumor was predominantly composed of vaguely defined lobules of plump cells with vesicular nuclei, bearing prominent nucleoli and surrounded by an abundant amphophilic cytoplasm (Figure 2A-C). Rare binucleate forms were seen (Figure 2A-B). The lobules were separated by bundles of reticulin (Figure 2D). Many blood vessels were cuffed by mature lymphocytes (Figure 2A) and a few eosinophilic granular bodies were detected (Figure 2C). Scant parenchymal microcalcifications were accompanied by an incipient microcyst formation. There were no mitoses. No xanthic cells, prominent cytologic atypia or fascicular arrangements were detected. Strong and often perivascular "band-like" staining for synaptophysin (Figure 2E) and rare cells, expressing neurofilament (not shown) were seen. Ki67 disclosed a few atypical nuclei and was in a range of 0.2%.


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