Pulmonary artery sarcoma is a rare tumor of the cardiovascular system. In many instances, the diagnosis is difficult and delayed. We present a case of a 68-year-old male who had a thrombus in the main pulmonary artery, and was later diagnosed with pulmonary artery sarcoma.
A 68-year-old Portuguese Male with no significant medical history was seen in the ED complaining of productive cough for 3 months, with associated intermittent fever, dyspnea, orthopnea, and weight loss. He was being treated with antibiotics and bronchodilators without improvement. The patient had a 40 pack-year smoking history, and he worked in a metal factory. On examination, his vital signs were stable, O2 sat 94%. Lung findings showed symmetrical air entry without rales, rhonchi or wheezes. He had no clubbing, but he had palpable inguinal and axillary lymph nodes. CXR on admission was unremarkable. His initial ABG was normal, FEV1 was 115% predicted. However, his V/Q scan showed total lack of perfusion of the left lung with small defect seen in the right apex (Fig 1). His Spiral CT showed thrombus in the main pulmonary artery extending into the left pulmonary artery, and extensive thrombus in the right pulmonary artery (Fig 2). Venous duplex of lower extremities showed negative for DVT, and the hypercoagulable work-up was also negative. His 2D echocardiogram showed moderately dilated right ventricle and pulmonary artery systolic pressure of 43mm/Hg. Patient was treated with continuous anticoagulation. Follow up chest CT 3 weeks later showed no improvement in the filling defect. Patient was sent for pulmonary thromboendarterectomy, and the surgical pathology showed presence of pulmonary artery sarcoma.
Pulmonary artery sarcoma (PAS) is an unusual tumor, with approximately 150 cases reported in the literature since Mendelstamm reported the index case in 1923. More than half of the patients are over the age of 50. Clinical and radiological features mimic those of pulmonary thromboembolic disease, thus, almost half of the time, it is frequently misdiagnosed as pulmonary embolus. By convention, PAS are classified under the common Soft Tissue Tumors (STT) that arises from fat, fibrous tissue, skeletal muscle, neurovascular elements and smooth muscle tissue. The histopathological diagnosis in our patient was Leiomyosarcoma, and the immunohistochemical (IHC) stains were positive for vimentin, smooth muscle actin and muscle actin, conferring a definitive diagnosis of high-grade spindle cell sarcoma. Pulmonary Artery Sarcoma is thought to arise from the multipotential mesenchymal cells of the intima or bulbus cordis. It frequently occurs in the pulmonary trunk. In this case, the lesion arose from the dorsal surface of the pulmonary trunk then spread distally into the right and left pulmonary arteries producing a saddle embolus. Without surgical resection, median survival for patients with PAS is a dismal 1.5 months irrespective of chemotherapy use. Resection independent of adjuvant therapy confers a survival of 10 months to 3.5 years.
Pulmonary Artery Sarcoma is unusual neoplasm, and they are frequently misdiagnosed as pulmonary embolism. It is important to consider PAS as a possibility when a persistent filling defect is present in the pulmonary artery, and there is no response to optimal anticoagulation treatment.
E.N. Elkady, None.