Intralobar Pulmonary Sequestration and Increased Serum CA 19-9.

Intralobar pulmonary sequestration is an uncommon congenital lung anomaly which consists of a mass of normal lung tissue not connected to the normal tracheobronchial tree and supplied by an anomalous systemic artery. Carbohydrate antigen 19-9 (CA 19-9) is widely accepted as a tumour marker for biliary, pancreatic and gastrointestinal cancer. However, CA 19-9 may also be increased in patients with benign disease. We describe the case of a 56-year-old woman with intralobar pulmonary sequestration who underwent unnecessary and extensive diagnostic abdominal examinations because of an increase in CA 19-9 serum levels.Knowledge of pulmonary sequestration causing increased serum CA 19-9 is important for the internist because it can help in the differential diagnosis even with neoplastic disease.Such awareness can also decrease the use of antibiotics.Familiarity with the condition can reduce the number of invasive examinations performed to exclude neoplasms of the gastrointestinal tract.