Renal tuberculosis: diagnosis with sonographically guided aspiration cytology

Sonographically guided fine-needle aspiration cytology was performed in 19 patients suspected to have renal tuberculosis. This procedure enabled a diagnosis of renal tuberculosis to be made in six of seven patients with urine cultures consistently negative for acid-fast bacilli and confirmed the diagnosis in nine patients with focal renal lesions on sonography and urine cultures positive for acid-fast bacilli. The fine-needle aspiration cytologic samples were positive for acid-fast bacilli in seven (44%) of the 16 confirmed cases, and acid-fast bacilli were present in 80% of the samples containing necrotic material. Epithelioid granulomas were present in 15 (94%) of 16 patients diagnosed with renal tuberculosis. One patient had no evidence of acid-fast bacilli or epithelioid granulomas, but seminal fluid ultimately grew acid-fast bacilli. Two patients (13%) with evidence of tuberculosis had minor self-limiting complications from the fine-needle aspiration: one perirenal hematoma and one abdominal wall intramuscular hematoma. Sonographically guided fine-needle aspiration cytology is useful as a means of diagnosing renal tuberculosis in patients with urine cultures negative for acid-fast bacilli, and is of value in defining the granulomatous nature of sonographically visible lesions in patients with positive urine cultures.