A 74-year-old woman undergoing hormone therapy for breast cancer at our hospital visited our department because of dysphagia and difficulty with oral intake. Examination revealed stenosis of the cervical esophagus and accumulation of food residues on the oral side of the stenosis. No lesion was found outside the esophageal wall but upper gastrointestinal endoscopy revealed a circumferential constriction of the esophagus with a smooth mucosal surface 20 cm from the incisors, and biopsy confirmed esophageal metastasis of the breast cancer. Tumors not exposed to the esophageal lumen can sometimes be missed even with multiple biopsies and may thus be difficult to diagnose. In such cases, use of boring biopsy and endoscopic ultrasound-fine needle aspiration can be useful for diagnosis.
