CNS involvement in DLBCL is not seen with which of the following organ involvement:

Ans: (a) OvaryWHO, CNS 2017, Page 272CNS Diffuse Large B Cell Lymphoma (DLBCL)Primary CNS lymphomas (PCNSLs) account for 2.4-3% of all brain tumours and 4-6% of all extranodal lymphomas.Most common location - Supratentorial region.PCNSL can affect patients of any age, with a peak incidence during the fifth to seventh decade of life.CNS lymphoma are at increase risk when DLBCL involves kidney and adrenals, and testicular DLBCL is closely linked with CNS DLBCL.MRI is the most sensitive technique to detect PCNSL, which is hypointense on T1-weighted images, isointense to hyperintense on T2-weighted images.Stereotactic biopsy* is the gold standard for establishing the diagnosis and classification of CNS lymphoma.PCNSLs are highly cellular, diffusely growing, patternless tumours. Centrally, large areas of geographical necrosis are common, and may harbour viable perivascular lymphoma islands.IHC - The tumour cells are mature B cells with a PAX5-positive, CD19-positive, CD20- positive, CD22- positive, CD79a-positive phenotype.