A 54-year- old women with macroscopic hematuria underwent a cystoscopy with bladder transurethral resection. A 3cm mass was found obscuring the right hemitrigone and ureteral orifice of the bladder. From this area, a 1.5cm calculus was removed. Adjacent tissue clinically suspicious for malignancy was excised. Grossly, the tissue consists of multiple pink-tan strips ranging form 0.5 to 1.8cm in greatest dimension, and measuring 5.0cm in aggregate. The specimen was entirely submitted.
Sections revealed a florid proliferation of mucin-producing glands lined by tall columnar and goblet cell. The lesion is confined within the lamina propria and has a lobular growth pattern (Fig 1). The cells have abundant cytoplasm with mucin production, and basally located nuclei (Fig 2). The nuclei are small, uniform in size and shape, and no nucleoli or mitotic figures are seen. Mucin extravasation is identified focally (Fig 3). Some gland-like structures lined by urothelium (Fig 4) are seen. There is chronic inflammation in the adjacent stroma (Fig 5).
Tubular-adenoma: The lesion consists of tubules, histologically identical to its counterpart in the colon. Lakes of extravasated mucin in the stroma can also be present in rare cases. But dysplasia in the epithelium is invariably present. The lining epithelium should be columnar and not urothelial in nature.
There are few documented examples of villous adenoma and tubular adenoma of the bladder; such a lesion is more common in the urachus. Villous adenoma of the bladder is more common in men than women.
Well differentiated adenocarcinoma or mucinous adenocarcinoma: The glands are irregular, and infiltrating with a desmoplastic response. Invasion into the muscularis propria is usually seen. The lining cells display cytologic abnormalities, including hyperchromatic enlarged nuclei, prominent nucleoli and mitotic figures. But these architectural and cytological features may be subtle. In mucinous adenocarcinoma, single atypical cells or nests floating in extracellular mucin are characteristic.
Cystitis cystica or cystitis glandularis: Both lesions are thought to arise from Brunn’s nests. They are found in up to 60-70% of serially sectioned bladders. Microscopically, the cysts in cystitis cystica contain eosinophilic material and are lined by cuboidal or flattened urothelium while the cystitis glandularis consists of glands lined by cuboidal to columnar cells with. Acute or chronic inflammation is usually present in the adjacent stroma.
Metastatic adenocarcinoma for other sites: This can be excluded clinically. Morphological and cytological evidence of malignancy is usually present. Certain cases may need immunohitochemical staining and other ancillary tests to establish metastatic nature of the tumor.
Florid cystitis glandularis (intestinal type) and cystitis cystica.
Key Features:
Table 1. Diagnostic features of cystitis glanulars and andenocarcinoma
Comment: Florid cystitis glandularis is uncommon. The major differential diagnosis is adenocarcinoma in this case. The lesion is quite extensive, and mucin extravasation is present, raising the concern for malignancy. However, the glands are orderly distributed in a lobular fashion. There is no invasion of muscularis propria. The lining cells are benign-looking, similar to normal colonic epithelium. The presence of cystitis cystica and chronic inflammation pinpoints a reactive process rather than neoplastic. In addition, mucin extravasation is not a diagnostic feature of malignancy in the bladder when associated with cystitis glandularis. Florid cystitis glandularis is usually cured by complete resection, but rare cases recur and may be associated with more worrisome findings. Therefore, clinical follow-up may be of value.
