Primary pulmonary artery sarcoma: A rare and overlooked differential diagnosis of pulmonary embolism. Clues to diagnosis

INTRODUCTION: Primary pulmonary artery sarcoma (PPAS) is a very rare tumor that mimics pulmonary embolism (PE) in clinical presentation and on imaging studies, therefore leading to diagnostic delay and increased patient mortality. PRESENTATION OF CASE: We discuss the case of 37-year-old man with a rapidly progressing PPAS, which was initially managed as PE. Imaging studies, particularly computed tomography and magnetic resonance imaging, were helpful in reaching the correct diagnosis. Because of the dismal prognosis of such cases, which improves by definite surgery, the patient underwent extensive surgical resection which got complicated by pulmonary reperfusion injury and intrapulmonary hemorrhage, and thus died. DISCUSSION: Owing to the rarity of the tumor, PPAS is often initially mistakenly diagnosed as PE, leading to a diagnostic delay and increased mortality. Having a high index of suspicion in "atypical PE" cases and a knowledge of the characteristic radiological and clinical features of PPAS may expedite the diagnosis and improve survival. Pulmonary artery distension by the mass on imaging studies and compression of neighboring structures are in favor of a tumor rather than PE. Additionally, tissue characterization on magnetic resonance imaging is particularly useful in differentiating tumor from PE. PPAS has a very poor prognosis which improves by early definitive surgery. Perioperative and late mortality however, remain high. CONCLUSIONS: Physicians should be alert of this tumor despite its rarity because diagnostic delay increases mortality. In this report, we summarize the features that differentiate PPAS from PE and the importance of imaging in diagnosing the tumor. (C) 2019 The Authors. Published by Elsevier Ltd on behalf of IJS Publishing Group Ltd.