Pulmonary artery sarcoma (PAS) is a rare but aggressive malignancy often misdiagnosed as pulmonary embolism (PE) due to similar clinical presentations. This case report presents an early 40s female with progressive dyspnea, hemoptysis, high pulmonary arterial pressures (112 mmHg), and right heart strain unresponsive to anticoagulation therapy. Imaging findings, including cardiac magnetic resonance and positron emission tomography-computed tomography, ultimately revealed PAS. This case highlights the importance of considering rare etiologies, such as PAS, in patients with PE-like symptoms refractory to standard treatment. Early detection using advanced imaging techniques can improve diagnostic accuracy and outcomes in this rare malignancy.
