[Pseudo-recurrence of lung tuberculosis based on the detection of smear AFB positive sputum due to excretion of necrotic material].

A 21-year-old man was admitted to our hospital for cough and hemoptysis. The patient showed smear positive pan-sensitive lung tuberculosis, and completed standard course of chemotherapy successfully. Six months after the completion of chemotherapy he had hemoptysis again. The chest radiograph showed that pre-existing tuberculoma-like shadow in the right upper lobe was changed to a cavity. Although sputum smear examinations revealed positive results several times, sputum culture was always negative. This clinical exacerbation was thought to be "pseudo-recurrence" due to excretion of necrotic material from the pre-existed abscess nodule. His disease improved without any anti-tuberculosis chemotherapy. Diagnosis of lung tuberculosis recurrence should be made on sputum culture positive results.