Question: A 64-year-old woman was referred to the gastroenterology service with an 18-month history of pharyngeal foreign body sensation. She reported regurgitation of a “cylindrical mass” with a choking sensation. Abdominal, head, and neck examinations were normal. Past medical history was significant for invasive micropapillary breast carcinoma; she underwent left mastectomy and chemoradiation therapy in 2007. Initial workup included a double contrast barium swallow, which did not demonstrate any esophageal abnormality.