A Case of Pulmonary Artery thrombosis in situ: A Great Masquerade: Case Report

We present a case of pulmonary artery thrombosis in situ (PATis) (a pioneer report in Sri Lanka), which involves de novo clot formation within the pulmonary arteries due to complex pathophysiology. A 69-year-old with multiple comorbidities presented with syncope, dyspnoea, fever, pleuritic chest pain with tachypnoea, hypoxia and hypotension. Initially treated as sepsis triggered Multi-Organ Dysfunction (NSTEMI with HF, AKI and Type-1 respiratory failure) that initially improved with multi-organ support (NIV, Inotropes, diuretic infusions, therapeutic LMWH, and antibiotics) despite oxygen dependency with dangerous levels of desaturation. Further, Echocardiogram and CTPA confirmed PATis, but an extensive etiology screen was negative. He improved long-term anticoagulation highlighting the importance of detecting PATis with masquerading clinical presentation for better outcomes.