Misdiagnosis of tuberculosis in patients with lymphoma.

BACKGROUND Since 1970, the incidence of lymphoma, a potentially curable disease, has risen by 80% in the general population and in HIV- positive patients. Given its clinical similarities to tuberculosis (TB), lymphoma may be misdiagnosed and patients treated unnecessarily with potentially harmful TB medication. OBJECTIVES (i) To identify patients with a histological diagnosis of lymphoma who were previously misdiagnosed with TB; and (ii) to raise awareness of lymphoma as a differential diagnosis when TB has not been confirmed. METHOD A retrospective study was conducted at Ngwelezane Hospital in rural KwaZulu-Natal, which serves an estimated population of 3 million. Using clinic notes and a questionnaire for patients attending the lymphoma clinic, we identified patients who had undergone failed TB treatment in the 12 months before their histological confirmation of lymphoma. RESULTS Twenty-one patients were included; 18 had been diagnosed with TB in the 12 months preceding the histological confirmation of lymphoma. All these patients subjectively reported TB treatment failure. CONCLUSIONS Delay in diagnosing lymphoma or its misdiagnosis is an important clinical problem in South Africa, with the condition often misdiagnosed as TB. This subjects patients to incorrect treatment and potential harm. We propose an algorithm for the work-up of patients presenting with lymphadenopathy +/- constitutional symptoms, to assist diagnosis and management in resource-poor settings.