Pulmonary sequestration with tuberculosis confined to the sequestrated lung.

Pulmonary sequestration is a relatively rare malformation. The incidence of common pyogenic infection in this anomaly is very high. We describe a non-symptomatic, 19-year-old man who was misdiagnosed with left lower lobe pneumonia, which was treated with antibiotics for nearly one month. Contrast-enhanced computed tomography (CT) with multiplanar reconstruction showed an aberrant artery originated from the left side of the descending aorta, and went through the infiltration of the left lower lobe. The patient underwent surgical removal of the affected lobe. Microscopy demonstrated resected sequestrated lung tissue that was mainly composed of caseous necrosis with Langhans cells. And the tuberculosis was just confined to the sequestrated lung without any other sites of lung tuberculous infection. The patient received subsequent antituberculous chemotherapy after his operation. At 4-month follow-up, his clinical status was excellent. There are few reports of sequestration combined with tuberculosis. This case showed us two things: first, a persistent infiltration or consolidation in a same segment, especially in the lower lobe, reminds us of the possibility of sequestration; and second, even if the diagnosis of sequestrated lung is confirmed, we should consider whether the patient has any other diseases, besides the tuberculosis.