[Primary renal lymphoma: a clinical analysis of 5 cases].

Objective: To improve the clinical diagnosis and treatment of primary renal lymphoma. Methods: Clinical data of 5 cases ( 2 male cases and 3 female cases) with primary renal lymphoma was reviewed. The age of patients was 55 to 70 years old, with a mean age of 62 years. No history of glomerulonephritis or nephropathy was recorded. All the cases were unilateral, including 3 cases in the left side and 2 cases in right. The major clinical manifestations were as follows: 2 cases of left lumbar pain, 1 case of gross hematuria, 1 case of hematuria under microscope, and 1 case receiving adjuvant chemotherapy after 12 years. The physical examination was as follows: the superficial lymph nodes of 5 cases were not enlarged; the liver, spleen and abdominal mass were not palpable; 2 cases had left upper quadrant tenderness ( with no rebound pain) and left kidney percussion pain. B-ultrasound, CT or MRI examination were performed before the operation, and renal malignant neoplasm was considered. No abnormality was found in bone marrow aspiration after operation. Four cases underwent radical nephrectomy and 1 case accepted partial nephrectomy. Four cases were administered with six cycles of R-CHOP (cyclophosphamide, pirarubicin, vincristine and prednisone) associated with rituximab, and 1 case was given six cycles of CHOP. Results: Five cases were diagnosed as non-Hodgkin's lymphoma, with 4 cases of diffuse large B-cell lymphoma of the kidney and 1 case of marginal zone B-cell non-Hodgkin lymphoma of mucosa-associated lymphoid tissue. The maximum diameter of the tumor was 3.5 to 10 cm, with the median diameter of 6.5 cm. The tumor was grey and white on the cutting surface, and the texture was fine. Under the microscope, the tumor cells were diffusely infiltrating, oval or polygonal, slightly larger than normal lymphocytes, with large irregular hyperchromatic nuclei. Four cases were followed up for 6 months to 2 years, with an average of 16 months. Chest X - ray and abdominal B-ultrasound were performed every 3 months, and abdominal CT or MRI scan was performed every 6 months. One case lost follow-up after 3 months. Except the case, the rest three are all alive. Conclusions: Primary renal lymphoma is rare. Most of the cases reported showed rapid systemic progression and a poor prognosis. There were no distinct characteristics in B-ultrasound and CT examination. Pathological examination is the key to its diagnosis. The surgical treatment combined with systemic chemotherapy can prolong survival of patients.