Intravascular bronchioloalveolar tumor of the lung presenting as pulmonary thromboembolic disease and pulmonary hypertension.

Intravascular bronchioloalveolar tumor, the pulmonary counterpart of epithelioid hemangioendothelioma, typically presents as bilateral pulmonary nodules in young women. We report a case of intravascular bronchioloalveolar tumor that clinically mimicked acute pulmonary thromboembolic disease initially and was subsequently proven to have pulmonary hypertension with right ventricular dysfunction by angiography. The diagnosis of intravascular bronchioloalveolar tumor was confirmed by immunohistochemical and ultrastructural studies after it was suspected on routine histologic examination. In addition, the tumor cells expressed glycoprotein cell adhesion molecule CD44, which has been implicated in increased tumor invasiveness and metastasis in various carcinomas and several aggressive non-Hodgkin's lymphomas.