Brain Pathology Case of the Month - April 2015

Contributed by Figen Soylemezoglu, Cigdem Himmetoglu, Kader K Oguz, Serap Saygi, Nejat Akalan
Hacettepe University Faculty of Medicine Department of Pathology, Neurology, Radiology, Neurosurgery


A 41 -year-old male patient administered to hospital with the complaint of medically intractable complex partial seizures since 3 years of age. The frequency of focal seizures despite multi-medication treatment was 4-5 /month. Brain MR imaging revealed a non-enhancing cortical lesion with subcortical involvement in the left parietal lobe. Imaging characteristics of the lesion on T1-W was peculiar in that both hypo- and isointensity was present with accompanying peripheral hyperintensity (Fig. 1). The lesion was hyperintense with microcysts on FLAIR (Fig. 2). Following lobectomy the patient remained seizure free and showed no evidence of tumor recurrence in the 48-months follow-up period.


On gross inspection, the lesion appeared to be centered in the cortex with expansion of the gyrus. Cut surface showed viscous consistency associated with multiple minute nodules and small cysts starting from gray matter and extending into white matter (Fig. 3). Microscopically, the tumor was predominantly composed of elongated cells forming rings around blood vessels of all sizes of the involved cortex and white matter (Fig. 4). The neoplastic cells are intermingled with brain parenchyma in an infiltrative pattern (Fig. 5). The spindle-shaped cells formed vague fascicles or whorls with basophilic background material that can be highlighted by alcian blue staining (Fig. 5, 6 and 7). These schwannoma-like nodules were in various sizes and mixed with pseudorosette forming solid component. No mitosis was detected. Along the subpial surface, the bipolar tumor cells aligned either parallel or perpendicular to the pia mater (Fig. 8). Focal microcalcifications were present (Fig. 9). The tumor cells showed strong cytoplasmic immunoreactivity for GFAP (Fig. 10). EMA immunohistochemistry showed cytoplasmic dots and rings (Fig.11). Evidence of adjacent focal cortical dysplasia was observed with cortical dyslamination and presence of hypertrophic neurons in layers 2 and 3. What is your diagnosis?


International Society of Neuropathology