&NA;Four clinicopathologic types of renal lymphoma (RL) are recognized: secondary RL, primary RL, renal intravascular lymphomatosis, and renal transplant lymphoma. Secondary RL is a lymphoma involving the kidney during the course of systemic lymphoma. Primary RL, defined as a lymphoma presenting with signs and symptoms related to the kidney, is first diagnosed from tissue taken from the kidney. It should be emphasized that in many cases of primary RL, a staging workup reveals simultaneous or subsequent lymphoma of other sites. Acute renal failure is a frequent initial presentation of primary RL. Lymphoma rarely involves the renal transplant as a manifestation of posttransplant lymphoproliferative disorder. Intravascular lymphomatosis is a rare variant of lymphoma in which the lymphoma cells are large and limited to vascular lumens, with minor perivascular expansion only in the terminal phases of the disease. The kidney is involved almost uniformly in intravascular lymphomatosis. Four cases of RL that encompass the morphologic spectrum of RL are reported, followed by a concise but comprehensive review of the different RL types. Familiarity with the many faces of RL promotes an intelligent diagnostic approach for this common condition and offers some insights into the fascinating biology of lymphoma.