Immunohistochemistry and electron microscopy of intravascular bronchioloalveolar tumor of the lung.

We report on an intravascular bronchioloalveolar tumor (IVBAT) detected in the lungs of a 45-year-old female. The results of the immunohistochemical and ultrastructural investigations stress the already suggested endothelial origin of the tumor. The clinical and histopathologic differential diagnoses between IVBAT and other rare tumors of the lung are discussed. Similarities of IVBAT with other more or less recently described endothelial tumors of the liver, skin and soft tissues are pointed out.