Concurrent Acute Coronary Syndrome and Pulmonary Embolism in a Patient With Gastric Malignancy: A Diagnostic and Therapeutic Challenge

Acute coronary syndrome (ACS) and pulmonary embolism (PE) are common, potentially life-threatening causes of acute chest pain with significant clinical overlap. Their concurrent occurrence is rare and presents important diagnostic and therapeutic challenges, particularly in patients with underlying malignancy. We report a case of a male in his 50s who presented with a two-week history of exertional chest pain and dyspnoea. Initial symptoms were attributed to iron deficiency anaemia, and subsequent outpatient investigation identified a type 1 gastric neuroendocrine tumour. He later re-presented with persistent symptoms, and further evaluation revealed bilateral pulmonary emboli and significant coronary artery disease (CAD). Management was particularly challenging given the competing risks of thrombosis and haemorrhage in the setting of active gastrointestinal malignancy. Following a multidisciplinary team discussion, percutaneous coronary intervention (PCI) was deferred until after tumour resection to mitigate bleeding risk. Following PCI, an individualised antithrombotic regimen was implemented to balance early stent protection with longer-term bleeding risk. This case demonstrates the challenges of diagnosing and managing concurrent ACS and PE in patients with gastric malignancy, highlighting the need for an individualised, multidisciplinary approach.