Contributed by Fabio Rogerio, MD, PhD1, Luciano de Souza Queiroz, MD, PhD1, Fabiano Reis, MD, PhD2, Aya Fukuda, MD2, Nivaldo Adolfo Silva Junior MD2, Andrei Fernandes Joaquim MD, PhD3
Departments of 1Pathology, 2Radiology and 3Neurology, State University of Campinas (UNICAMP). Campinas, Brazil.
A 32-year-old man presented with a 7-month history of headache and 2-month visual loss. Neurologic examination was unremarkable except for low visual acuity, worse in the left eye. Magnetic resonance imaging showed symmetrical cortical lesions in the midline, affecting predominantly both cingulate gyri and the upper corpus callosum. Lesions appeared multifocal, often limited to the cerebral cortex, confluent with speckled appearance, high signal intensity in T1-weighted images (Fig. 1), isointense in T2, strong contrast enhancement (Fig. 2), hypoperfusion with low regional cerebral blood flow values. Multivoxel spectroscopy showed increased choline/creatine ratio (2.97). There was prominent symmetrical edema of centrum semiovale. No changes were found in the leptomeninges.
Stereotaxic biopsy yielded multiple small fragments in which epithelioid and giant cell granulomas were found in a small focus only (Fig. 3). Elsewhere there was recent infarction with xanthomatous macrophages, swollen endothelial cells and necrotic neurons (Fig. 4). Necrotizing vasculitis with fibrinoid and neutrophil infiltration and thrombosis limited to small vessels was ubiquitous. Ziehl-Neelsen stain was positive in the necrotic areas, though not within the granulomas (Fig. 5). What is your diagnosis?