Uncommon Presentation of Primary Renal Lymphoma

A 38-year-old man presented with weakness and a 2-year history of diffuse papulovesicular itching skin lesions. In addition, he suffered from mild bilateral flank pain since 3 months earlier. He had no systemic disease or recent infectious diseases. Physical examination was unremarkable except for generalized macules, papules, vesicles, and scratch scares on the trunk and extremities. Serum creatinine level was slightly high. Computed tomography showed diffuse multiple round hypodense renal masses spread in both kidneys without infiltration of psoas muscle or other internal organ. Kidney biopsy showed severely infiltrated neoplastic CD45- and CD20-positive cells. Diffuse large B-cell lymphoma was diagnosed. The patient was referred for chemotherapy, after which serum creatinine returned to its normal level and skin rashes resolved. Primary renal lymphoma is mostly associated with immunodeficiency states.1 The ultrasonic manifestation of renal lymphoma shows multiple hypoechoic lesions within renal parenchyma which must be differentiated from solid tumors, metastases to the kidney, xanthogranulomatous pyelonephritis, and immunoglobulin G4-related kidney disease.2 Paraneoplastic syndrome associated with primary renal lymphoma is a rare condition. Paraneoplastic dermatoses are a diverse faction of clinical manifestations of lymphoma with a benign appearance.3 In conclusion, chronic skin lesions accompanied by itching can be the first sign of a major disease including an internal malignancy.