ABSTRACT
Introduction: Gastrointestinal (GI) malignancies are associated with paraneoplastic sequelae such as non-bacterial thrombotic endocarditis (NBTE) and inflammatory myopathy. We describe a unique case in which a metastatic gastric malignancy presented without typical GI symptoms and instead was discovered after pursuing a unifying diagnosis for a constellation of cardiac, neurologic, and musculoskeletal manifestations. Case Description/Methods: A 61-year-old woman presented to a tertiary medical center with shoulder and thigh soreness and weakness with functional decline in the 3 months prior to presentation. Her medical history included morbid obesity, atrial fibrillation (AF), diabetes mellitus, and resolved COVID-19 pneumonia. Her physical exam was notable for proximal muscle weakness and tenderness, bilateral ptosis, vertical gaze deficit, and 4/6 diastolic murmur. Laboratory values included CRP 3.2 mg/dL (normal range <0.8 mg/dL), ESR 51 mm/hour (, 30 mm/hour), creatine kinase 822 IU/L (25-185 IU/L), and aldolase 24.3 U/L (<8.1 U/L). A muscle biopsy was performed revealing an equivocal inflammatory myopathy process. The gaze deficit prompted an MRI of the brain, revealing multiple thromboembolic strokes. COVID related hypercoagulability and AF were considered, however given the murmur on exam, a transesophageal echocardiogram was performed which showed large mobile echodensities on the aortic valve. She was empirically treated for infectious endocarditis, though with concern for NBTE and occult malignancy. CT scan of the abdomen and pelvis with IV contrast was then performed, demonstrating metastatic liver lesions and enlarged gastrohepatic and cardiophrenic lymph nodes. In discussion with radiology, it was suggestive of a gastric primary malignancy. Carcinoembryonic antigen and carbohydrate antigen 19-9 returned at 4965 ng/mL (<3 ng/mL) and 1878 U/mL (<35 U/mL), respectively. The patient ultimately decided to pursue hospice care. Discussion: In this unusual case, a gastric malignancy presented with paraneoplastic phenomena in multiple systems, but without GI symptoms. Physical exam findings led to critical diagnostic steps. NBTE is associated with malignancy, commonly carcinomas of the stomach, biliary system, pancreas, ovaries, or lung. Inflammatory myopathy can also share strong associations with cancer. Our report highlights a unique diagnostic journey and should alert physicians to include GI malignancy on the differential when presented with NBTE and myopathy..