Malignant haemangiopericytomas and haemangioendotheliosarcomas: an immunohistochemical study.

Formalin-fixed, paraffin-embedded material from 15 haemangioendotheliosarcomas and eight malignant haemangiopericytomas was stained with an immunohistochemical technique for the presence of factor VIII-related antigen (F VIII-RAg), actin, laminin and for reactivity with the lectin Ulex europaeus I (UEA-I). Haemangioendotheliosarcomas stained with both F VIII-RAg and UEA-1; however, UEA-I was found to be the more sensitive of the two, reacting also with the poorly differentiated tumours. Haemangiopericytomas reacted negatively with UEA-I; surprisingly, some of these tumours exhibited a weak positivity in staining for F VIII-RAg, possibly supporting the theory about intermediate forms between haemangioendotheliosarcomas and haemangiopericytomas. Laminin was found in most of the haemangioendotheliosarcomas and was useful in illustrating their vascular growth pattern. Haemangiopericytomas also reacted positively for laminin, but the intensity of staining was less pronounced. Positive staining for actin was demonstrated in both tumour types.

Radiation treatment of giant-cell tumour of bone (osteoclastoma).

Ten patients with giant cell tumours of the bone were treated by radiation therapy. Indications were non-radical primary surgery in 8 cases and recurring lesions in 2. Tumour doses ranged from 23 to 75 Gy delivered with supervoltage equipment in 8 cases. There were 3 recurrences after radiation therapy, all occurring in patients with tumor doses less than 39 Gy; 2 of these had received orthovoltage therapy and 2 died later from lung metastases. Modern supervoltage irradiation is probably as effective as surgery which is nevertheless recommended in operable cases.