Urothelial carcinoma with villoglandular differentiation: a study of 14 cases.

Tumors of the urinary bladder may have a variety of histological patterns. Tumors with either glandular or villous features, such as villous adenomas, in situ adenocarcinomas, invasive adenocarcinomas, and variants of urothelial carcinoma such as micropapillary carcinomas have been described. However, urothelial carcinomas with both villous and glandular features have not been well characterized. We identified 14 cases of urothelial carcinoma with villoglandular differentiation. These cases were defined as having villoglandular features if they contained superficial finger-like processes lined by epithelium having true glandular lumina. Mean patient age at presentation was 70 years (range: 46-84 years) with a male predominance (5:1). A total of 3 cases (21%) were non-invasive, five cases (36%) had lamina propria invasion, five cases (36%) had muscularis propria invasion and one case (7%) had extravesicular extension. A concurrent high-grade papillary urothelial carcinoma component was identified in 11 cases (79%), micropapillary component in 5 (36%) cases, in-situ urothelial carcinoma component in 3 cases (21%), plasmacytoid component in 3 cases (21%), invasive adenocarcinoma in 2 cases, sarcomatoid carcinoma component in one case (14%), and small-cell carcinoma component in 1 case (7%). Cystitis cystica et glandularis was present in 3 cases (21%). Angiolymphatic invasion was identified in 3 cases (21%). Histologically, the villoglandular components were composed of finger-like processes lined by glands intimately admixed with high-grade urothelial carcinoma. Many of the glands had cribriform features lined by non-mucin producing cuboidal to columnar cells. Urothelial carcinoma with villoglandular differentiation are high-grade tumors typically seen in elderly males, characterized by superficial filliform processes lined by glands intimately admixed with high-grade urothelial carcinoma (in situ or invasive) and other aggressive variants of urothelial carcinoma. These relatively rare tumors should be recognized as a variant of urothelial carcinoma.