Brain Pathology Case of the Month - June 2018

Contributed by Sheng Chen, MD, PhD1*, Meng-Sha Yao, MD1*, Fei Yuan, MD2
1Department of Neurology & Institute of Neurology, Medicine, and 2Department of Pathology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.


A 66-year-old Chinese woman presented with progressive cognitive decline, difficulty for calculating and dizziness for 2 years. She complained of bilateral limb weakness and gait disturbance which was characterized by small steps without falling for 1 month. No headache, nausea, vomiting, dysphagia, dysarthria, urinary incontinence, seizure attack, fever. Neurological examination showed an apathetic patient with severe cognitive decline (MMSE score was 14/30) and decreased muscle strength with limb spasm bilaterally. No hepatosplenomegaly and lymphadenopathy. Lumbar puncture showed normal pressure with mild lymphocytosis, glucose of 36 mg/dl, and protein of 60 mg/dl. PCR of CSF HSV and CMV returned negative. CSF was also negative for IgG oligoclonal bands. Serum EBV IgG was positive. EEG showed slowing of the normal background diffusely. Cranial MRI exhibited diffuse white matter changes, involving periventricular area, frontoparietal white matter, without mass effect (Figures 1A, 1B). Repeated MRI revealed progressive leukoencephalopathy involving brainstem and cerebellar peduncle (Figures 1C, 1D) with mild periventricular enhancement 5 months later (Figure 1E). Brain biopsy targeting periventricular deep white matter was therefore performed.


Microscopic histopathological examination of the surgical specimen from deep white matter revealed diffuse atypical lymphoid cells with enlarged round nuclei (Figures 1F, 1G). Necrosis was absent. These tumor cells were not cohesive. They infiltrated sub-cortical white matter without solid mass formation. Mitotic figures were significant. Additional immunohistochemical studies indicated that the tumor cells were positive for CD20 (Figure 1H), CD79? (Figure 1I). In addition, EBER in situ hybridization (ISH) was positive (not shown) and the ki-67 was 50% (Figure 1J). The immunostaining was negative for CD 3, CD5, CD10 and CD 56 (not shown). What is your diagnosis?


International Society of Neuropathology