Primary renal lymphoma masquerading as metastasis in a patient with primary breast cancer and systemic lupus erythematosus.

We describe a case of a 56-year-old woman with systemic lupus erythematosus (SLE) who presented with breast mass, axillary lymphadenopathy, and renal mass. The breast lesion was diagnosed as infiltrating ductal carcinoma. However, the renal mass evaluation was suggestive of a primary lymphoma. Primary renal lymphoma (PRL) with breast cancer in an SLE patient has rarely been reported.