A case series of primary urinary tract neuroendocrine neoplasms

Neuroendocrine neoplasms (NENs) are a heterogeneous group of tumors that originate from neuroendocrine cells. They are common in the digestive system (such as the stomach, intestines, and pancreas) and the respiratory system, but they are rare in the urinary system, comprising less than 1%-2% of urinary malignancies. These tumors typically lack specific clinical symptoms and are usually diagnosed through postoperative pathological examinations. Due to their rarity, the clinical awareness of NENs remains insufficient in the community.

Clinical data of 10 patients diagnosed with urinary tract neuroendocrine neoplasms (UT-NENs) were retrospectively collected and analyzed. We summarized their clinical characteristics and treatment outcomes, with the aim to improve our understanding of urinary tract NENs and further optimize personalized therapeutic strategies for these rare tumors.

In our study, 4 out of 10 patients were admitted for hematuria. Seven out of 10 patients had lesions in the bladder. Five of 6 cases with NEN muscularis propria invasion occurred in the bladder. All 3 deceased patients had bladder NEN. None of them received postoperative radiotherapy and chemotherapy. Five out of 6 surviving patients received postoperative radiotherapy and chemotherapy.

Hematuria is the main symptom in UT-NENs. The bladder is the most common location of UT-NENs, while bladder lesions are more likely to present as poorly-differentiated neuroendocrine carcinoma. In the present case series, patients who received postoperative radiotherapy and chemotherapy showed a trend toward better long-term prognosis and survival.