Villoglandular Neoplasm of the Bladder vs. Secondary Involvement from a GI Primary

Urothelial carcinoma with villoglandular differentiation (UCVGD) is a rare aggressive form of urothelial carcinoma [1]. It is typically associated with high-grade urothelial carcinoma or adenocarcinoma in rare cases. [1] This case explores a 38-year-old male with a history of bladder inflammation and hematuria for 15 years. He was diagnosed with this rare entity of urothelial carcinoma with cystitis cystica, intestinal metaplasia and reactive urothelial changes. This case is unique because two possible origins for this tumor were identified but they could not be separated on morphology or immunoprofiling. The differential diagnosis included a primary enteric type villa-glandular neoplasm arising from the bladder or a direct metastatic extension of a colonic adenocarcinoma.

Subtypes of urothelial carcinomas include squamous, glandular or trophoblastic differentiation [6]. Most patients present with painful urination, irritation, hematuria, increased urinary frequency or urgency [7]. The variants of urothelial carcinomas not only present with diagnostic challenges but they often are associated with advanced disease at presentation. [10] Glandular differentiation, as seen in this case, includes the presence of true glandular spaces, with tubular or gland-like lumina and variable mucin production [2]. The kidneys and Bladder are common sites for glandular differentiation [2].

Cystitis cystica was also seen in this patient and it is a common incidental finding in the bladder neck and trigone. It develops as a result of a reactive process in response to chronic inflammation [3]. Intestinal metaplasia in the bladder is defined by the replacement of the urothelium by benign colonic mucosa with the presence of goblet cells which produce mucin. [4]

Bladder cancer is the 6^th most common cancer in the United States and over 95% of bladder cancers are urothelial carcinomas [5]. This is a case of a high grade enteric type villo-glandular neoplasm with high grade dysplasia and carcinoma in situ. The patient did not have any documented history of any colonic adenocarcinomas and the immunoprofile and morphology could not help distinguish if the tumor arose from colon or from the existing urothelial carcinoma. Therefore, current treatment guidelines for urothelial carcinomas were followed. Treatment options for invasive bladder cancer include intravesical therapy for non-muscle-invasive tumors [8], and muscosal resection [9] and radical cystectomy with pelvic lymph node dissection [7, 10] for later stage cancers.