Leiomyosarcoma of the pulmonary hilar vessels.

Leiomyosarcomas are uncommon tumors. They have a predilection for deep soft tissues, with a rare group arising in medium-sized or large veins, far less frequently in arteries. We report a case of a 63-year-old man, with an enlarging mass located in the left pulmonary hilar region which was discovered on a routine chest radiograph. Cytology of the sputum and bronchoscopic biopsies did not reveal any malignant cells. Over 5 months observation, there was a clear progression of the mass, and the patient finally underwent a left pneumonectomy which allowed the diagnosis of an intravascular leiomyosarcoma partially destroying major arteries and veins in the hilar region. A review of the literature reveals 67 cases of leiomyosarcoma involving the pulmonary artery. None of these cases had an associated venous pathology. The disease is found mainly in adult women. Clinical diagnosis is very difficult because most of the cases have no specific clinical signs; the major differential diagnosis is that of pulmonary thrombo-embolism. Prognosis depends on histological degree of the tumor and extent of the disease, metastases occur mainly in the liver, lung, and brain and less frequently in regional lymph nodes. Treatment is always surgical, chemotherapy is ineffective and the effectiveness of radiotherapy depends on the total dose of irradiation. Sarcomas of hilar blood vessels have a very poor prognosis with a one year survival estimated, from the onset of symptoms, at 20%.