Causes and presenting features of pulmonary infarctions in 43 cases identified by surgical lung biopsy.

BACKGROUND Although pulmonary infarction is usually associated with pulmonary thromboembolism, it can occur with other disorders such as vasculitis, angioinvasive infections, sickle-cell disease, tumor embolism, and pulmonary torsion. STUDY OBJECTIVE To identify causes and presenting features of pulmonary infarctions diagnosed by surgical biopsy in a consecutive series of patients encountered at a single institution. DESIGN Retrospective review. SETTING Tertiary care, referral medical center. PATIENTS Forty-three patients with pulmonary infarction identified on surgical lung biopsy over a period of 7 years, January 1996 through December 2002. RESULTS The median age of these 43 patients was 55 years (range, 22 to 85 years); 17 patients (40%) were women, and 26 patients (60%) were men. Thirty-five patients (81%) had a smoking history. Twenty-eight patients (65%) presented with solitary or multiple lung nodules/masses of undetermined etiology. The underlying cause was identifiable in 31 cases (72%) based on a review of clinical, laboratory, radiologic, and histopathologic data. The two most common causes were pulmonary thromboembolism (18 cases, 42%) and pulmonary infections (5 cases, 12%). Thromboembolic pulmonary infarctions typically presented as solitary or multiple nodules located in the subpleural regions. Other causes included diffuse alveolar damage in two cases (5%), pulmonary torsion in two cases (5%), and one case each of lung cancer, amyloidosis, embolotherapy, and catheter embolism. In 12 cases (28%), the underlying cause was not directly identifiable but was probably due to previous pulmonary thromboembolism. CONCLUSION We conclude that although pulmonary thromboembolism is the most common cause of pulmonary infarction identified by surgical lung biopsy, a variety of other causes are clinically encountered, including infections, inflammatory or infiltrative lung diseases, pulmonary torsion, malignancy, and nonthrombotic embolism. Pulmonary infarction should be considered in the differential diagnosis of peripheral lung nodules or masses.