A 36-year-old woman presented with multiple shadows, up to 1 cm in diameter, in both lungs revealed by routine chest radiography. Right thoracotomy showed numerous firm nodules in the middle and lower lobes. Histological examination of the wedge biopsy disclosed an epithelioid haemangioendothelioma of the lung (positive immunohistochemical reaction for factor VIII-associated antigen). Eight years later the patient remains symptom-free without treatment and the radiological picture is almost unaltered. Another woman, 22 years old, had a skin nodule near the right external malleolus. It was removed and found to be a semi-malignant haemangioendothelioma. Five years later a chest radiograph showed finely nodular shadowing in both lungs which roused suspicion of sarcoidosis. She had steroid therapy for one year, but the radiological findings remained unchanged. After a further 10 years a round lesion, some 3 cm in diameter with partial calcification, was found in the right lower lobe. Histological examination revealed an epithelioid haemangioendothelioma with a positive immunohistochemical reaction for factor VIII-associated antigen. She subsequently complained of severe pain in the left shoulder (with histologically demonstrated bone involvement by the neoplasm) together with rapidly increasing dyspnoea. Seventeen years after the original diagnosis she died of rapidly progressive diffuse lymphangiomatosis carcinomatosa. Post mortem secondary deposits were found in the liver as well.