An Unusual Cause of Rectal Pain

Abstract

Question: A 79-year-old man presented with a 1-week history of rectal pain. He had passed a painful, jagged stool with fresh red rectal bleeding. The patient reported that it felt like passing “broken glass.” He had previously undergone a laparoscopic anterior resection with a nonfunctioning ileostomy for adenocarcinoma of rectum (T3 M0 N1) 7 years prior. His ileostomy had been closed and there had been no evidence of disease recurrence on follow-up. In addition, he has atrial fibrillation, hypertension, type 2 diabetes mellitus, and had acute cholecystitis with calcification that was managed conservatively 4 years ago. On examination, he was hemodynamically stable. His abdomen was soft and nontender. An internal rectal examination was tender with intraluminal glass-like material palpable within the rectum. Admission blood tests including liver function tests were normal apart from a C-reactive protein of 37 mg/L and lactate of 3.1 mmol/L. Previous imaging (plain radiograph [Figure A]) from 4 years ago is compared with contemporary imaging (plain radiograph (Figure B) and a computed tomography scan of the abdomen and pelvis with contrast was performed (Figure C, D). What is the most likely diagnosis? Look on page 1181 for the answer and see the Gastroenterology website (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and images in GI. A previous plain radiograph (Figure A) from 4 years before presentation demonstrated an intact porcelain gallbladder. Imaging at the current presentation, a plain radiograph (Figure B) and a computed tomography scan of the abdomen and pelvis (Figure C) demonstrated a porcelain gallbladder and cholecystocolonic fistula. A large portion of the porcelain gallbladder wall had fragmented, passed via the fistula into the transverse colon and had transited to the rectum (Figure D). The patient underwent examination under anesthesia and removal of this part of the porcelain gallbladder wall per rectum (Figure E). Histopathological analysis demonstrated fragments of fibrous tissue with the epithelial lining entirely replaced by extensive calcification and metaplastic bone formation with no evidence of malignancy (Figure F; microscopic section; original magnification ×12.5; Figure G, original magnification ×100, demonstrating metaplastic bone formation). The histopathologist favored a final diagnosis of porcelain gallbladder wall passing via the cholecystocolonic fistula into the colon to the rectum. Postoperatively, the patient recovered well with no further intervention required for the gallbladder or cholecystocolonic fistula. Porcelain gallbladder is also known as calcified gallbladder or calcifying cholecystitis, where the gallbladder becomes encrusted with calcium, brittle, hard, and takes on a bluish discoloration.1Geller S.A. de Campos F.P. Porcelain gallbladder.Autops Case Rep. 2015; 5: 5-7Crossref Google Scholar Patients are often asymptomatic, but occasionally present with right upper quadrant pain, a palpable mass, or symptoms of biliary obstruction.1Geller S.A. de Campos F.P. Porcelain gallbladder.Autops Case Rep. 2015; 5: 5-7Crossref Google Scholar The diagnosis is frequently incidental on an abdominal radiograph or computed tomography scan.1Geller S.A. de Campos F.P. Porcelain gallbladder.Autops Case Rep. 2015; 5: 5-7Crossref Google Scholar The decision to manage porcelain gallbladder conservatively or with cholecystectomy considers the presence of symptoms, biliary complications, and comorbid medical conditions. Although porcelain gallbladder has previously been regarded as a risk factor for gallbladder adenocarcinoma, a recent review of 7 published case series that included 60,665 cholecystectomies suggests that cancer risk is low (<3%).2Khan Z.S. Livingston E.H. Huerta S. Reassessing the need for prophylactic surgery in patients with porcelain gallbladder: case series and systematic review of the literature.Arch Surg. 2011; 146: 1143-1147Crossref PubMed Scopus (57) Google Scholar Among patients who are asymptomatic with good functional status, prophylactic cholecystectomy is recommended despite the limited data regarding true risks of gallbladder cancer because the prognosis of gallbladder cancer is poor.2Khan Z.S. Livingston E.H. Huerta S. Reassessing the need for prophylactic surgery in patients with porcelain gallbladder: case series and systematic review of the literature.Arch Surg. 2011; 146: 1143-1147Crossref PubMed Scopus (57) Google Scholar Gallstone ileus caused by large stones passing through duodenal fistulae causing small bowel obstruction is common. We previously reported a case of large bowel obstruction caused by a large gallstone passing via cholecystocolic fistula into the sigmoid colon.3Ventham N.T. Eves T. Raje D. et al.Sigmoid gallstone ileus: a rare cause of large bowel obstruction.BMJ Case Rep. 2010; 2010Crossref Scopus (4) Google Scholar Previous cases of sigmoid gallstone ileus have been managed conservatively, endoscopically (including use of ultrasonic lithotripsy) and surgically.3Ventham N.T. Eves T. Raje D. et al.Sigmoid gallstone ileus: a rare cause of large bowel obstruction.BMJ Case Rep. 2010; 2010Crossref Scopus (4) Google Scholar This case is the first reported of actual fragments of gallbladder itself, rather than stones, passing via the fistula into the colon. The presentation was with rectal pain alone, rather than any right hypochondral or other colonic or biliary symptoms. Currently, the present authors are not suggesting this as a novel way to perform a cholecystectomy.