Association of precursors with invasive adenocarcinoma of the gallbladder: A clinicopathological study

Background: The current WHO classification proposed high-grade biliary intraepithelial neoplasm (BilIN) and intracholecystic papillary neoplasm (ICPN) as precursors of the gallbladder carcinoma (GBC). Herein, conventional GBCs (cGBCs) were pathologically examined with respect to these two precursors. Methods: Forty-seven cases of GBC with grossly visible invasions were collected from Fukui Saiseikai Hospital. The association of two precursors was analyzed referring to pathologic features of cGBCs and post-operative survival.Results: 20 cGBCa (42.6%) were associated with either of two precursors in the surrounding mucosa: high-grade BilIN in 15 cases (31.9%) or ICPN in 5 cases (10.6%). Association of precursors was not related to gross types of and histological differentiation of cGBC. cGBCs without precursors showed frequent vascular/perineural invasion and lymph node metastasis, though cGBCs with and without precursors presented a similar post-operative survival. High-grade BilIN and ICPN associated with cGBCs showed more complicated cytoarchitectural features compared with those with no or focal invasion.Conclusion: More than 40% of cGBCs were associated with high-grade BilIN or ICPN, and the former was a frequent precursor. cGBCs without precursors showed aggressive pathologic features. Clinical detection of these precursors may make early treatment of cGBCs possible.