A 79-year-old Filipino female with sick sinus syndrome status-post pacemaker placement, atrial fibrillation on anticoagulation, history of a stroke with no residual deficits, and coronary artery disease presented to the hospital with a syncopal episode. Physical examination showed hemodynamic stability, negative orthostatic vital signs, and normal neurologic and cardiovascular findings. Electrocardiogram, computed tomography (CT) and CT angiography of the head and neck, bilateral carotid ultrasound, and pacemaker interrogation were unremarkable. Laboratory studies were significant for hemoglobin of 5.8g/dL. Hemoglobin one month prior to presentation was 8.0g/dL; an anemia work-up had not been performed previously.
The patient denied abdominal pain, nausea, vomiting, melena, or hematochezia. She had never undergone a screening colonoscopy and denied a family history of GI malignancy. Upon further laboratory evaluation, ferritin was found to be less than 20ng/mL, concerning for iron-deficiency anemia. Despite a discordant clinical history, in order to evaluate for a possible source of bleeding, upper and lower endoscopies were performed. Esophagogastroduodenoscopy (EGD) revealed a 3-4cm oozing gastric mass. Biopsy confirmed gastrointestinal stromal tumor. CT imaging completed for staging purposes showed liver nodules suspicious for metastases, indicating likely stage IV cancer. The patient was deemed a poor surgical candidate given her co-morbidities and age, and treatment was initiated with imatinib.
Discussion: Gastrointestinal stromal tumors (GIST) are a rare and clinically diverse set of mesenchymal tumors of the GI tract, comprising only 1% of primary GI malignancies. Approximately one half of these tumors are located in the stomach and are primarily identified by histopathological staining of a mucosal biopsy. GIST shows no gender predominance and has a median age at diagnosis of sixty years. The highest incidence rates are seen in regions of East Asia, though interestingly, the only known identifiable risk factor is an association with neurofibromatosis type I.
Conclusions: This case demonstrates the importance of maintaining a broad differential when evaluating syncope, a common reason for admission to the hospital. It also demonstrates the need to investigate all abnormal laboratory values and consider further work up if warranted. In this patient, the only manifestation of stage IV GIST was syncope due to anemia, which was particularly unexpected in the absence of overt GI bleeding.