An asymptomatic patient with multiple solid renal masses: errors in diagnosis

A 63-year-old man was referred to us in December 1997 from an out-patient clinic for further work-up and treatment of a ‘presumed bilateral renal carcinoma’. At admission, the patient had no symptoms except for a vague suprapubic discomfort with occasional dysuria, both of which had started several weeks earlier. He had a history of similar symptoms 7 years earlier (1990). At that time, he had dysuria for several weeks before seeking medical consultation, which resulted in a presumed diagnosis of prostatitis. His intravenous urogram then was normal, except for a double pelvis in the left kidney, and his ultrasound examination had revealed a small prostatic adenoma. His symptoms had disappeared completely after a short course of rifampicin. No further examinations were carried out as his symptoms did not reappear until November 1997, when ultrasonography showed a prostatic adenoma and, incidentally, an area of increased echogenicity at the upper pole of the right kidney. A computed tomographic (CT) scan disclosed multiple solid areas in both kidneys, leading us to diagnose a malignancy [1–3]. The physical examination on admission revealed a healthy appearing individual with a blood pressure of 144/85mmHg. Laboratory tests provided the following results: white blood cell count 4760/mm, with 58.6% of neutrophils; slightly increased erythrocyte sedimentation rate (ESR; 13mm/h, normal <10), C-reactive protein <3.5mg/dl (normal <5); normal blood urea nitrogen (BUN; 30mg/dl), creatinine (1.0mg/dl), urea (46ml/min) and creatinine clearance (98ml/min). Urinalysis was negative for protein, blood and nitrites. The microscopic examination of the urine showed hyaline casts and a few red and white blood cells. Urine cultures yielded no growths of common organisms or acid-fast bacilli. Cultures from the urethral meatus and of semen were also negative for many pathogens, including Chlamydia, Gardenella, Mycoplasma and Ureoplasma urealyticum.