Progressive renal failure in a patient with lung adenocarcinoma

We present an interesting case of a young female smoker who was hospitalized for shortness of breath and acute renal insufficiency (serum creatinine = 2.8 mg/dL). Few weeks prior to admission, she was discovered to have a right lung mass, and a biopsy confirmed lung adenocarcinoma. Her work-up revealed an unremarkable urinalysis quantitatively and on microscopic analysis. Renal ultrasound demonstrated enlarged bilateral unobstructed kidneys, while a nuclear scan showed increased activity in both kidneys. Renal biopsy established the diagnosis of diffuse metastatic infiltration of both kidneys from primary lung adenocarcinoma. Her renal function worsened despite initiation of chemotherapy. Carcinomatous infiltration of the kidneys is an extremely rare and unusual cause of renal injury that must be suspected in a patient with cancer and large kidneys.