Contributed by Lin Liu, MD, PhD and Geoffrey Murdoch, MD, PhD
The patient was a 13-year-old girl with a long standing history of frequent headaches and a recent syncopal event. The syncope lasted for about 10 seconds with no seizure like activities. There were no complains of fevers/chills, nausea/vomiting/diarrhea, chest pain, short of breath or any other neurological symptoms. Family history was not significant.
An MRI of the head was performed and it showed a complex mixed solid and cystic partially calcified enhancing tumor centered in the right lateral ventricle body, extending to the brain parenchyma, involving the right thalamus/basal ganglia region. There was no significant hydrocephalus or mass effect (Figures 1 and 2). Of note, cavum septum pellucidum was also identified. A bicoronal craniotomy and transcallosal approach for resection of tumor was performed.
Histologic examination of Hematoxylin & Eosin sections (Figures 3, 4 and 5) reveals fragments of brain parenchyma with a minimally infiltrating glial lesion. The lesion showed sheets of large epithelioid cells with copious eosinophilic glassy cytoplasm, eccentric nuclei, vesicular chromatin, and many with prominent nucleoli. Multifocal calcifications are present (Figure 3). There is minimal fibrillary background. No mitoses or necrosis is identified. IMMUNOHISTOCHEMISTRY
The tumor cells are weakly and focally GFAP positive (Figures 6 and 7), strongly and diffusely positive for Vimentin (Figure 8), and negative for Synaptophysin (Figure 9). Ki-67 proliferation index is less than 5% in the most densely staining foci (Figure 10).