Urothelial Papilloma of the Urinary Bladder: A Case Report and Literature Review of a Rare Entity

Abstract

Urothelial papilloma is a rare benign neoplasm composed of a delicate fibrovascular core covered by normal urothelium. In this report, we present a case of an incidentally detected endovesical papillary growth in ultrasound scan (USS) during a routine check-up, suggestive of bladder tumor which was also suggested by CT urography. The tumor was initially managed with transurethral resection and immediate intravesical instillation of mitomycine C 40 mg. The histopathologic assessment of the specimen concluded that the growth was "urothelial papilloma with no atypia or malignancy." Although papilloma is unequivocally benign, it can recur; recurrences can be multiple and can occur years after the initial diagnosis occasionally with progression to carcinoma, hence long-term surveillance is essential. Our case was followed up for a year with no signs of recurrence or progression and long-term surveillance will be done annually.

Keywords: bladder tumors; case report; urinary bladder; urothelial carcinoma; urothelial papilloma.

Figure 1. Cystoscopic view.

A: Cystoscopic view showing an isolated exophytic pedunculated soft pinkish growth with delicate papillary structures. B: A drawing showing the relation of the growth to the ureteric orifice.

Figure 2. Microscopic picture.

The UP of the urinary bladder with: (A) Discrete papillary structures, hierarchical branching without invasion to lamina propria or muscularis propria (H&E, 40x). (B) Slender papillae having fibrovascular cores (H&E, 100x). (C) Fibrovascular cores lined by urothelial cells not exceeding seven to eight layers. The cells show uniform bland oval nuclei and pink cytoplasm without atypia or mitosis (H&E, 400x). (D) Occasional cores showing marked edema, giving it a bulbous look. The lining urothelium appears normal with prominent umbrella cell layer (H&E, 200x). UP, urothelial papilloma