Solitary Pulmonary Nodule: TB or not TB

September 14, 2005
Samer Alkhuja, MD

For the past 2 days, a 30-year-old man had experienced scant hemoptysis. He had also lost a significant amount of weight-5 kg (11 lb)-over the last 2 months. The patient, a recent emigrant from Ecuador, had no history of tuberculosis (TB) or of exposure to this disease, and he had not been skin tested with purified protein derivative (PPD). He denied exposure to risk factors for HIV infection.

For the past 2 days, a 30-year-old man had experienced scant hemoptysis. He had also lost a significant amount of weight-5 kg (11 lb)-over the last 2 months. The patient, a recent emigrant from Ecuador, had no history of tuberculosis (TB) or of exposure to this disease, and he had not been skin tested with purified protein derivative (PPD). He denied exposure to risk factors for HIV infection.

Examination results were unremarkable save for a nontender, 1 × 1-cm, posterior mass in the right testicle. A PPD test produced a 12 × 15-mm induration at 72 hours. A chest film and CT scan of the chest showed a solitary pulmonary nodule in the superior segment of the left lower lobe, without cavitation.

Pulmonary TB was suspected, and the patient was placed on respiratory isolation. No earlier chest studies were available for comparison, and induced sputum smears were negative for acid-fast bacilli. An ultrasonogram of the testis revealed a cyst in the epididymis and excluded tumors.

Bronchoscopy was performed to rule out TB. No endobronchial lesions were seen. Smears of bronchial washings revealed acid-fast bacilli, and all cultures grew Mycobacterium tuberculosis. Examination of transbronchial biopsy specimens was negative for malignancy.

Treatment with four antituberculous medications was begun. The patient's hemoptysis stopped. The number of acid-fast bacilli on sequential sputum smears declined, and sputum smears and cultures were negative for pathogens 4 months later. An HIV test was negative, and repeated chest films showed resolution of the solitary nodule.

A solitary pulmonary nodule is completely surrounded by normal lung tissue and is not associated with hilar enlargement or atelectasis. This finding in a patient should prompt review of previous chest x-ray studies for comparison. Additional investigations should include CT of the chest and fine-needle biopsy or bronchoscopy. Dr Samer Alkhuja of Greenwich, Conn, warns of the greatly increased possibility of TB if a patient with hemoptysis comes from a country in which TB is endemic (in this case, Ecuador), even in the absence of radiologic signs of necrotizing pneumonia or cavitation. If multiple sputum smears are negative for acid-fast bacilli but clinical or radiologic signs suggest TB, consider a further diagnostic work-up.

FOR MORE INFORMATION:1. Midthun DE, Swensen SJ, Jett JR. Approach to the solitary pulmonary nodule. Mayo Clin Proc. 1993;68:378-385.