title: Diverticular bleeding and the pigmented protuberance (sentinel clot): clinical implications, histopathological correlation, and results of endoscopic intervention.
abstract: Over a 3-yr period, we performed colonoscopy on five patients (mean age 71 yr) in whom a specific diverticulum that contained a pigmented protuberance (PiP) was unequivocally identified as the cause for hemorrhage. Four of these individuals had endoscopic bipolar cauterization of the PiP, and two patients had surgery.
  
  
  OBJECTIVE
  To (1) determine the clinical significance of an intradiverticular PiP, (2) correlate endoscopic features of a PiP with histopathological findings and, (3) assess results of endoscopic treatment for affected patients with lower GI bleeding.
  
  
  METHODS
  Medical charts were reviewed to garner data and assess outcome for patients. The bleeding diverticulum in one surgical case was detected in the resected specimen, and histological examination was performed.
  
  
  RESULTS
  The mean number of transfusions, bleeding days, and lowest hemoglobin concentration before definitive treatment was 4.8, 3.4, and 8.4 gm%, respectively. All patients rebled before treatment. In all instances, the PiP projected through the neck of the diverticulum, which was actively bleeding in two patients. Endoscopic bipolar cautery directed at the PiP achieved permanent hemostasis in three of four subjects (75%) (morbidity 0%). Endoscopic therapy failed in one subject, and a hemicolectomy was performed. Histological evaluation of the resected specimen showed erosion of a medium sized artery into the diverticulum. The PiP represented a sentinel clot (not a visible vessel) adherent to a breach in the vessel wall. A patient who had surgery instead of endoscopic therapy had a prolonged, complicated postoperative course.
  
  
  CONCLUSIONS
  (1) The presence of an intradiverticular PiP may identify a subset of patients at risk for severe recurrent diverticular bleeding. (2) Histopathological analysis showed the PiP to be a sentinel clot rather than a visible vessel. (3) In patients with severe recurrent diverticular bleeding, endoscopic treatment of the vessel beneath this lesion may be a viable alternative to surgery.
authors.affiliation: Department of Pathology, Desert Samaritan Hospital, Mesa, Arizona, USA.
authors.forename: P G
authors.initials: PG
authors.lastname: Foutch
authors.forename: K
authors.initials: K
authors.lastname: Zimmerman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002425:Cautery; D003108:Colonic Diseases / Q000150:complications* / Q000473:pathology / Q000628:therapy; D004241:Diverticulum, Colon / Q000150:complications* / Q000473:pathology / Q000628:therapy; D004564:Electrocoagulation; D016099:Endoscopy, Gastrointestinal; D006471:Gastrointestinal Hemorrhage / Q000150:complications* / Q000473:pathology / Q000628:therapy; D006801:Humans; D013927:Thrombosis / Q000150:complications* / Q000473:pathology