Non-Hodgkin's lymphoma with uncommon clinical manifestations: A case report.

Extranodal lymphoma occurs in ~40% of all patients with lymphoma and has been described in virtually all organs and tissue. However, diffuse large B-cell lymphoma (DLBCL), which is the most common histological subtype of non-Hodgkin's lymphoma (NHL), primarily arising in the retroperitoneal region has been rarely reported. Primary retroperitoneal lymphoma without renal or ureteral involvement affecting the genitourinary system has not been reported until now. In this article, we report the rare case of a young female suffering with primary DLBCL located simultaneously in the retroperitoneal and gastrointestinal region. The first sign of this disease was renal colic. Pathological assessment was performed using immunohistochemistry staining, revealing positivity for CD20 and Ki67. DLBCL was the final confirmed diagnosis. Obtaining a definitive histological diagnosis by surgery and using exactly chemotherapy played an essential role in the treatment of our patient. This case serves as a reminder to include the differential diagnosis of primary retroperitoneal NHL when a patient presents with a retroperitoneal mass and the first symptom is renal colic.