A 69-year-old woman with no history of malignant disease presented with complaints of ptosis, diplopia, and left upper eyelid fullness. Computed tomography showed soft tissue infiltration of the left superior orbit. Biopsy was performed through an anterior orbitotomy. Histopathology revealed a mucinous adenocarcinoma. Subsequent systemic evaluation included esophagogastroduodenoscopy, which revealed a primary gastric malignancy.