Immunohistochemical and ultrastructural study of early lesions of intravascular bronchioloalveolar tumor with liver involvement.

Autopsy findings including immunohistochemical and ultrastructural study of intravascular bronchioloalveolar tumors (IVBAT) of the lung and liver which were incidentally found in a 68-year-old man were reported. The tumors presented as several, small nodular lesions in bilateral lungs and liver. Immunohistochemical study using the antibody against Factor VIII-related antigen and electron microscopic study suggested endothelial nature of both pulmonary and hepatic lesions. The study by using anti-estradiol antibody revealed the presence of estrogen in the cytoplasm of neoplastic cells, suggesting the possibility of the presence of estrogen receptors in the cells. Although the result is still preliminary, some role of estrogen in the development of IVBAT is suggested. The hepatic lesions have been thought to be metastases from the pulmonary IVBAT but the other possibilities such as primary hepatic or multicentric origin must be considered. Review of the previous reports of IVBAT disclosed several cases which were associated with liver involvement.