Question: An 81-year-old man with a long history of experiencing a globus sensation over the suprasternal area was admitted for massive hematemesis. He denied alcohol or tobacco use, but was taking medication for diabetes mellitus, dyslipidemia, and hypertension. His medicines included glimepiride, acarbose, atorvastatin, and olmesartan medoxomil. On physical examination, his heart rate was 108 beats per minute and his blood pressure was 88/56 mmHg. His abdominal examination was unremarkable. Laboratory studies showed normocytic anemia (hemoglobin, 8.7 g/dL; mean corpuscular volume, 85.0 fL). Emergent esophagogastroduodenoscopy was performed (Figure A) and revealed a bleeding lesion. Successful hemostasis was achieved. Subsequently, barium esophagram was also performed (Figure B). What is the diagnosis? See the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI. Initially, much blood in the proximal esophagus interfered with the visual field of the endoscope. After the blood was aspirated and flushed, a large diverticulum over the proximal cervical esophagus was seen together with several ulcers and a 1-mm visible vessel over the base. The needle bevel was carefully inserted at an approximately 45° angle into the mucosa and 0.01% epinephrine solution was injected around the vessel. Heat probe coagulation was then used to achieve complete hemostasis. The barium esophagram demonstrated a 6.6 × 5.2 × 4.7-cm diverticulum with contrast filling. The diverticulum was on the lateral side of the proximal cervical esophagus and was confirmed to be a Killian-Jamieson diverticulum. A Killian-Jamieson diverticulum is an outpouching through a muscular gap in the anterolateral wall of the proximal cervical esophagus immediately below the cricopharyngeus.1Ekberg O. Nylander G. Lateral diverticula from the pharyngo-esophageal junction area.Radiology. 1983; 146: 117-122Crossref PubMed Scopus (68) Google Scholar It is different from the commonly known Zenker's diverticulum, which is located on the posterior wall of the pharyngoesophagus immediately above the cricopharyngeus. The pathogenesis of a Killian-Jamieson diverticulum is unknown, but it is hypothesized to be similar to that of Zenker's diverticulum, which is owing to a functional outflow obstruction in the esophagus caused by inappropriate constriction during swallowing.2Tang S.J. Tang L. Chen E. et al.Flexible endoscopic Killian-Jamieson diverticulotomy and literature review (with video).Gastrointest Endosc. 2008; 68: 790-793Abstract Full Text Full Text PDF PubMed Scopus (39) Google Scholar Although often asymptomatic, the Killian-Jamieson diverticulum has clinical manifestations that include dysphagia, globus sensation, and cough. Very few may have the aspiration pneumonia that is more commonly seen in Zenker's diverticula.2Tang S.J. Tang L. Chen E. et al.Flexible endoscopic Killian-Jamieson diverticulotomy and literature review (with video).Gastrointest Endosc. 2008; 68: 790-793Abstract Full Text Full Text PDF PubMed Scopus (39) Google Scholar, 3Rubesin S.E. Levine M.S. Killian-Jamieson diverticula: radiographic findings in 16 patients.Am J Roentgenol. 2001; 177: 85-89Crossref PubMed Scopus (84) Google Scholar Bleeding of Killian-Jamieson diverticula has not been previously reported. Diverticulitis caused by food or drug stasis is posited as the causal factors of ulceration within the diverticulum. This experience offers a safe and effective endoscopic treatment for this type of true esophageal diverticular bleeding. Treatment in Killian-Jamieson diverticula, like in Zenker's diverticula, is reserved for symptomatic patients only. Therapy may include external surgical sac incision or internal endoscopic diverticulotomy to allow for diverticular drainage into the esophagus.2Tang S.J. Tang L. Chen E. et al.Flexible endoscopic Killian-Jamieson diverticulotomy and literature review (with video).Gastrointest Endosc. 2008; 68: 790-793Abstract Full Text Full Text PDF PubMed Scopus (39) Google Scholar Because of concerns regarding old age and because the discomfort was tolerable and did not worsen, the patient and his family asked for conservative management of the esophageal diverticulum. They were given education like drinking water after meals or drug intake with intent to flush the diverticulum. The patient had no recurrent bleeding after 1 year of follow-up.