Urinary Bladder Small Cell Neuroendocrine Carcinoma, also known as small cell neuroendocrine carcinoma of the urinary bladder, is related to bladder small cell carcinoma and carcinoid tumors, intestinal. An important gene associated with Urinary Bladder Small Cell Neuroendocrine Carcinoma is SYP (Synaptophysin). Affiliated tissues include lymph node and bone marrow.