PRIMARY PULMONARY ARTERY SARCOMA. Report of Two Autopsy Cases Studied by Immunohistochemistry and Electron Microscopy, and Review of 110 Cases Reported in the Literature

Two cases of primary pulmonary artery sarcoma are reported. The patient in the first case was a 61-year-old male with a two-year history of cough and exertional dyspnea, who died of intractable cardiac failure two months after admission without establishment of a diagnosis related to the etiology of cardiac failure. Autopsy revealed a sessile tumor within the pulmonary trunk and a solitary metastatic lesion in the lung. Histologic, immunohistocyto-chemical and electron microscopic studies were performed and a diagnosis of malignant mesenchymoma was made. The patient in the second case was a 32-year-old male complaining of exertional dyspnea and back pain. Radiologic studies indicated a mediastinal tumor involving the pulmonary artery. Exploratory thoracotomy revealed that the mediastinal mass arose from the left pulmonary artery. He died of respiratory failure 26 months after onset of his initial symptoms. Histologic, immunocytochemical and electron microscopic studies of both surgical and autopsy materials revealed a malignant fibrous histiocytoma. One hundred ten previously reported cases of this tumor are reviewed, and its clinicopathologic and morphologic features and probable histogenesis are discussed. ACTA PATHOL JPN 38: 883∼896, 1988.