Massive Bilateral Pulmonary Embolism Presenting as Isolated Abdominal Pain: An Atypical Presentation and Incidental Detection in Dual Immune-Mediated Disease.

Pulmonary embolism (PE) is a potentially life-threatening condition that classically presents with chest pain, tachycardia, and dyspnea. Atypical manifestations such as gastrointestinal symptoms may occur, particularly in elderly patients with multiple comorbidities that can potentially skew and delay diagnosis. We report the case of a 79-year-old woman with a history of multiple myeloma and myasthenia gravis who presented with acute-onset abdominal pain with nausea and vomiting. Computed tomography (CT) of the abdomen and pelvis was obtained to evaluate suspected intra-abdominal pathology that incidentally detected pulmonary arterial filling defects in the right lower lobe of the lung. Subsequent CT pulmonary angiography confirmed extensive bilateral pulmonary emboli. The patient was urgently transferred to a tertiary care center for mechanical pulmonary thrombectomy with successful hemodynamic stabilization. This case highlights an atypical presentation of life-threatening PE that presented predominantly with gastrointestinal symptoms and was incidentally identified on abdominal imaging. Clinicians should maintain a high index of suspicion for PE in patients with unexplained gastrointestinal complaints, particularly in the setting of comorbidities such as malignancy and autoimmune disease that may mimic symptoms.