Rare Occurrence of a Poorly Differentiated Neuroendocrine Tumor of the Bladder

Abstract

Neuroendocrine tumors rarely occur in the urinary bladder. They can be carcinomatous, subdivided into small cell and large cell pathology. Small cell carcinoma of the bladder is a rarity that may present at an advanced pathologic stage. No treatment regimens have been standardized for local or metastatic disease. Review of the recent literature shows equivalent survival data for localized disease treated with chemoradiotherapy combined with either bladder sparing surgery or radical cystectomy. Patients with significant comorbidities are an additional challenge. We report a case of poorly differentiated neuroendocrine tumor of the bladder, which could not be classified as small or large cell carcinoma, complicated by significant comorbidities. After management with transurethral resection of the tumor, adjuvant chemotherapy, and radiation, the patient is alive and asymptomatic nearly 1 year after initial TURBT with no evidence of disease recurrence.

Figure 1

3.2 × 1.7 × 2.7 cm mass in the anterior wall of the urinary bladder.

Figure 2

(a) Dark tumor cells fill stroma, splaying pink smooth muscle bands to the left (H&E, 100x). (b) Tumor nuclei are irregular, with scant cytoplasm, with some showing spots of nuclear clearing suggestive of salt and pepper, with some tumor cells juxtaposed to suggest molding, and with many pyknotic nuclei, indicative of a rapidly growing tumor.