title: Morule-like features and tumor-associated lymphoid proliferation in gallbladder carcinoma.
abstract: A unique case of gallbladder carcinoma with morule-like features and tumor-associated lymphoid proliferation in a 53-year-old man is presented. The surgically resected gallbladder demonstrated a polypoid tumor with a thin stalk, measuring 1.3 x 0.5 cm. Histologically, a well-differentiated tubular adenocarcinoma was accompanied by multiple spindle cell nodules. The stroma of the tumor showed dense lymphocytic infiltrate. Immunohistochemically, the spindled cell nodules were diffusely positive for cytokeratin AE1/AE3 but negative for S-100, NSE, and chromogranin A. The immunohistochemical results considered to be spindle cell nodules were morule-like features. Intranuclear expression of beta-catenin was observed in morule-like features and carcinoma cells. Ki-67 labeling index was 16.7% of carcinoma cells, but Ki-67 immunoreactivity was negative in spindle cell nodules; therefore, morule-like features were considered to represent metaplastic foci of carcinoma cells and not nodular growth of carcinoma cells. Although the exact pathogenesis of marked lymphoid proliferation in the stroma remained unknown, tumor-produced substances may derive from lymphoid proliferation.
authors.affiliation: Department of Pathology, Japan Self Defense Forces Sapporo General Hospital, Hokkaido 062-8610, Japan. zwq04043@nifty.ne.jp
authors.forename: Yu
authors.initials: Y
authors.lastname: Sakai
authors.forename: Shinji
authors.initials: S
authors.lastname: Sano
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Koike
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*; D002449:Cell Aggregation; D049109:Cell Proliferation; D005706:Gallbladder Neoplasms / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D008221:Lymphoid Tissue / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D051176:beta Catenin / Q000378:metabolism
chemical_list: D051176:beta Catenin