[Apparently primary pulmonary hemangiopericytoma. Apropos of 7 cases].

Seven cases of pulmonary hemangiopericytoma (presumed to be primary v.i.) are reported. Personal observations on these cases combined with 43 already described in the literature allow certain characteristics of the disorder to be accurately defined. Clinically, primary pulmonary hemangiopericytoma raises the aetiological problem of a peripheral solitary tumour beyond endoscopic vision. Until the present time the diagnosis has always been made by thoracotomy. Transpleural pulmonary biopsies may allow a preoperative diagnosis. Silver stains and electron microscopy enable an anatomo-pathological diagnosis. Histological studies can neither distinguish between benign and malignant forms nor differentiate between primary or metastatic hemangiopericytoma. For this reason there is always a long period of doubt whether the tumour is primary; only prolonged survival of the patients after excision will confirm whether the tumour was a primary or not. Treatment is essentially surgical. It seems that new techniques in radiotherapy (high energy) and new possibilities of chemotherapy (with Adriamycin) are capable of improving the prognosis of the malign form. However, such a therapeutic strategy remains to be defined as these tumours are so rare.