[1392] Metaplasia in the Gallbladder: Populational Differences in the Incidence of Intestinal Metaplasia Supports Its Association with Carcinoma

O Basturk, O Tapia, JC Roa, E Bellolio, C Delgado, S Bandyopadhyay, I Coban, D Thirabanjasak, JM Sarmiento, H Losada, NV Adsay. NYU, NY; Frontera U., Temuco, Chile; WSU, Detroit; Emory U., Atlanta; Emory U., Atlanta

Background: There is conflicting data regarding the incidence/clinical significance of metaplasia in the gallbladder (GB) carcinogenesis.
Design: Metaplasia was investigated in 600 benign cholecystectomies from 3 different risk groups: A) High Risk (HR): 300 chronic cholecystitis (CC) cases from Chile where the GB carcinoma (CA) incidence is very high; B) Low/Minimal Risk (L/MR): 160 CC and 60 morbid obesity cases from N. America; C) No Risk (NR): 80 GBs removed as a part of pancreatoduodenectomy for pancreatic diseases. An average of 8.7 cm of GB tissue/case was examined; cases with autolysis were excluded. Metaplasia score: 0; 1: <1 mm, 1 focus; 2: 1-5 mm or >1 foci; 3: >1 foci, at least 2 of which >5 mm but <70% of mucosa; 4: >70% of mucosa. The incidence of metaplasia was also correlated with the degree of chronic inflammation, sclerosis, rokitansky aschoff sinuses (RAS) and cholesterolosis.
Results: Intestinal metaplasia (IM): Overall 10.1% of the cases had IM. There was a progressive increase in the incidence and quantity of IM from NR to L/MR to HR groups (p=0.001). Most IM was represented as goblet cells while the participation of absorptive cells/brush-border appeared to be very minimal. Pyloric metaplasia (PM): The overall incidence of PM was very high (44.1%) and in 3% of the cases, there was diffuse transformation of the mucosa into pyloric type glands. PM did not increase in incidence with CA risk (Its incidence was higher in the L/MR group vs HR or NR; p=0.003). No association was identified between the incidence of IM or PM and the degree of chronic inflammation, sclerosis, RAS and cholesterolosis.

	High Risk Group	Low/Minimal Risk Group	No Risk Group
IM	n=43 (14.3%)	n=17 (7.7%)	n=1 (1.2%)	p=0.001
PM	n=126 (42%)	n=115 (52.2%)	n=24 (30%)	p=0.003

Conclusions: There is a significant progressive increase in the incidence of IM in the GB, increasing with the risk of CA, supporting its association with CA. PM, on the other hand, appears to be more ubiquitous, not associated with CA risk. The incidence of either metaplasias does not correlate with the degree of chronic changes, suggesting that they may be a direct result of the chemical milieu rather than being a secondary product of inflammation.
Category: Liver & Pancreas

Monday, March 9, 2009 9:30 AM

Poster Session I Stowell-Orbison/Autopsy Award # 203, Monday Morning