Correct Answer: A. Intestinal metaplasia with high grade dysplasia

Histological Description: The case consists of polypoid fragments composed of numerous glands with cytological atypia with enlarged, hyperchromatic nuclei, prominent nucleoli, increased mitoses and loss of polarity. Focally, some of the glands have residual goblet cells. The glands are relatively evenly distributed without individual infiltrating cells and without an associated desmoplastic stromal reaction.

Discussion: Assessment of glandular lesions of the bladder is entirely analogous to how one would assess a gastrointestinal (GI) glandular lesion. Intestinal metaplasia of the bladder is a benign glandular proliferation where the urothelial mucosa and proliferating glands of cystitis cystica/cystitis glandularis becomes lined by intestinal-type epithelium. This epithelium resembles normal colon crypts with cytologically bland, basally situated, small round nuclei, and diffuse goblet cells. The presence of focal residual goblet cells in this case is evidence that this lesion is primary in the bladder and arising from intestinal metaplasia, as opposed to from a villous adenoma or from another site. The current lesion also lacks a surface villiform architecture. Intestinal metaplasia may have abundant acellular extracellular mucin, and occasionally can involve the muscularis propria. Uncommonly, intestinal metaplasia may have dysplasia, and has the same morphology as adenomas in the GI tract. If the cytology is that of a tubular adenoma of the GI tract, it is considered moderate dysplasia in intestinal metaplasia. If glands show loss of polarity and greater cytological atypia, as seen in the current case, then it is considered intestinal metaplasia with high grade dysplasia, again analogous to diagnosing high grade dysplasia in an adenomatous polyp in the GI tract. Intestinal metaplasia without dysplasia has no increased risk of adenocarcinoma in the bladder, except for increased risk of adenocarcinoma in exstrophy patients. Although there are only limited studies, intestinal metaplasia with dysplasia is associated with concurrent adenocarcinoma of the bladder. If incompletely excised, patients who are diagnosed with glandular dysplasia require a repeat biopsy to completely remove the lesion and clinical follow-up.