Imaging features of the renal lymphoma: case report and literature review.

Renal affection is common in disseminated non-Hodgkin's lymphoma (NHL) which is known as secondary renal lymphoma (SRL). Primary renal lymphoma (PRL) is an exceedingly uncommon disease, which accounts for less than 1% of all renal masses. Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of NHL in both primary as well as secondary renal lymphomas. PRL is of paramount importance clinically as it is usually managed with neo-adjuvant chemotherapy followed by nephrectomy in contrast to the more frequently seen renal cell carcinoma, which is treated surgically. This outstanding difference in management challenges the longstanding approach that preoperative biopsies are not mandatory prior to nephrectomy for renal masses. Because of its relative rarity, the imaging features of PRL have been described in a few studies, and having an understanding of these typical imaging patterns is crucial for making an accurate diagnosis and differentiation from other renal malignancies. Here, we present a case of a secondary renal lymphoma and discuss its differential imaging features.