Diversity of imaging and pathological features at different stages of primary central nervous system lymphoma.

Objective The clinical, imaging and pathological manifestations of one patient at different stages of primary central nervous system lymphoma (PCNSL) have been analyzed to disclose its pathogenesis. Methods and Results A 29-year-old female patient showed recurrent onsets. On the first onset, the main clinical manifestation was blurred vision and visual field defect. Cranial MRI showed a patchy lesion in the right parietal and occipital lobes without obvious occupying sign. T₁WI showed slight low-intensity sign, T₂WI and FLAIR showed high-intensity signs. Enhanced scanning showed heterogeneous punctate enhancement. The lesion disappeared gradually after glucocorticoid impact therapy. Headache, vomiting and left limb paralysis were the main clinical manifestations on the second onset, and MRI showed a lesion in the right frontal and parietal lobes with obvious occupying sign and solid enhancement, low- intensity on T₁WI, high-intensity on T₂WI and FLAIR. The tumor was totally removed under microscope. Histological findings showed large tumor cells, rich cytoplasm, nuclei with various sizes and shapes, conspicuous mitosis, patchy necrosis, and interstitial small vessel hyperplasia. Immunohistochemical staining showed that membrane of tumor cells was positive for CD20, and nuclei were positive for paired box gene 5 (PAX5) and multiple myeloma oncogene 1 (MUM1). In a few tumor cells, membrane was positive for CD10 and CD30, and nuclei were positive for cyclin D1. Besides, tumor cells were negative for CD3, anaplastic lymphoma kinase (ALK) and glial fibrillary acidic protein (GFAP). Ki-67 labeling index was about 80%. EBER in situ hybridization (ISH) assay showed that mRNA coded by Epstein-Barr (EB) virus was negative. The tumor showed angiotropic characteristics, and the walls of involved blood vessels were wrapped and destructed. The final diagnosis was confirmed as diffuse large B cell lymphoma. Conclusions PCNSL has various imaging features, revealing as diffuse infiltrating or solid occupying lesions, which emerge as the result of its angiotropic characteristics. [ABSTRACT FROM AUTHOR]