Immunohistochemical investigation of selected endothelial markers in pulmonary epithelioid haemangioendothelioma.

Epithelioid haemangioendothelioma (EH) is a very rare neoplasm. It is assumed that these tumours derive from vascular endothelial cells. The aim of the study was to identify the immunohistochemical profile of tumour cells in lung EH. The unique material consisting of eight cases of lung EH was collected and examined by immunohistochemistry with three antibodies: CD-31, CD105, both marking vascular endothelial cells, and D2-40, marking lymphatic endothelial cells. In all cases, the cytoplasm of tumour cells showed widespread expression of CD-31. Reaction with CD-105 antibody gave a positive result mainly in the cytoplasm of tumour cells located at the periphery of tumours, especially in highly cellular neoplasms containing spindle cells. Reaction with D2-40 antibody in most cases was negative. The presence of a few capillary vessels with positive endothelial cells was revealed in two cases at the periphery of the tumour. Only in one case of a highly cellular tumour did a small portion of spindle cells show a positive reaction to D2-40. The above studies confirmed the origin of EH mainly from vascular endothelial cells. Medications inhibiting vascular endothelial growth factors can be considered as a treatment option for multifocal EH that does not qualify for surgical intervention.