Conclusion
The coexistence of bilharzial cystitis and mixed large and small cell neuroendocrine tumors in the bladder presents a rare and intriguing clinical scenario. While bilharzia is typically associated with squamous cell carcinoma in the bladder, emerging evidence from other organs suggests potential interactions between bilharzia infection and the development of neuroendocrine tumors. We strongly believe that the same mechanism involved in these interactions outside the bladder is implicated in our case. Further research is warranted to elucidate the underlying mechanisms driving this unique coexistence and to explore potential implications for diagnosis, treatment, and patient outcomes in affected individuals.