Osseous Metaplasia of the Gallbladder: Report of Two Cases
Osseous metaplasia is rarely seen in the gastrointestinal tract. Its occurrence in the gallbladder is even more rare; only 7 cases have been reported thus far. Two additional cases are described herein: one was an incidental finding and the other simulated an intramural gallstone in a chronically inflamed, calculi-containing gallbladder. The patients were a 32-year-old man and a 52-year-old man who presented with abdominal pain. Ultrasonography revealed small gallstones in 1 patient. Laparoscopic cholecystectomies were performed and histologies were consistent with chronic cholecystitis and cholelithiasis with intramucosal bone formations. One of the patients also had an adenomyoma in the fundus. Osseous metaplasia of the gallbladder is a rare event. It is mostly incidental and although its etiology and clinical significance are unknown, it may mimic a gallstone, which could affect treatment options. The pathogenesis could be osteogenic stimulation as a result of the inflammatory process.
1.Vigorita VJ. Orthopaedic Pathology. New York: Lippincott Williams and Wilkins; 1999. p. 60.
2. Rosai J. Gallbladder and extrahepatic bile ducts. In: Rosai J, editor. Rosai and Ackerman's Surgical Pathology. 9th ed. Mosby; 2004. p. 1041.
3. Indyk J, Shipton EA. Heterotopic bone formation in the gall-bladder. Med J Aust 1957;44:9–11.
4. Ortiz-Hidalgo C, Baquera-Heredia J. Osseous metaplasia in polypoid cholesterosis. Am J Surg Pathol 2000;24:895. [CrossRef]
5. Yosepovich A, Nass D, Zagatsky M, Kopolovic J. Chronic cholecystitis with bone metaplasia. A case report. Pathol Res Pract 2002;198:765–6. [CrossRef] 6. Nelson JJ, Kahn AG. A case of bone metaplasia of the gallbladder epithelium. South Med J 2009;102:322–4. [CrossRef]
7. Lin MY, Shikle JF. To pick a 'bone' with the gallbladder. South Med J 2009;102:773–4. [CrossRef]
8. Rege TA, Vargas SO. Cholecystitis and cholelithiasis associated with an intramural fasciitis-like proliferation and osseous metaplasia. Pediatr Dev Pathol 2011;14:80–3. [CrossRef]
9. Il'chenko AA, Orlova IuN, Khomeriki SG. Bone metaplasia in the gallbladder wall. Eksp Klin Gastroenterol 2011:86–90.
10. Micseh G. Knochenbildung im Gallenblasenkrebs und in seinen Metastasen. Frankfurt Z Path 1933;44:430–8.
11. Cavazza A, De Marco L, Asioli S, Pastore L, Gardini G. Stromal osseous metaplasia in metastatic adenocarcinoma of the gallbladder. Tumori 1999;85:133–4.