Abstract
We report a case of diffuse large B-cell lymphoma (DLBCL) of the retroperitoneum showing a cohesive cytological pattern. Imprint smears of the lesion were easily diagnosed as DLBCL by Diff-Quick staining, but tumor cells with large round nuclei and clear pale cytoplasm also showed a cohesive pattern in Papanicolau staining, meaning that clear-cell renal carcinoma could not be ruled out. DLBCL rarely affects retroperitoneal lymph nodes or soft tissue. Our case thus indicates that DLBCL may show a cohesive pattern both in cytological and histological specimens.
