Lung metastasis of malignant epithelioid hemangioendothelioma mimicking a primary intravascular bronchioalveolar tumor. A histologic, ultrastructural, and immunohistochemical study.

A 40-year-old woman presented with multiple nodules in both lungs and a small tumoral mass at the level of the left brachial artery. A pathologic diagnosis of pulmonary intravascular bronchioloalveolar tumor (IVBAT) and epithelioid hemangioendothelioma of the limb was established. Morphologic and immunohistochemical studies highly suggest that both tumors are manifestations of the same neoplastic process. In this case a metastatic nature of the IVBAT is suggested. The diagnosis of pulmonary IVBAT should be followed by a search for sclerosing vascular tumors elsewhere. Finally, the results substantiate the vascular origin of the IVBAT.