Clinicopathologic Observation of 6 Cases with Neuroendocrine Carcinoma of the Urinary Bladder

OBJECTIVE To discuss the pathologic characteristics and theprognosis of neuroendocrine carcinoma of the bladder(NECB)in order to assist in making a precise diagnosis and to effectivelytreat the disease.METHODS Clinicopathologic features of the 6 cases with NECBwere analyzed retrospectively.The personal data of the patientsand the pathologic and immunohistochemical characteristics ofthe tumor were investigated.The follow-up of these patients wasconducted over a time period ranging from 3 months to 9 years.RESULTS Transurethral resection of the bladder tumorwas performed in all 6 patients.Based on the results of thepathologic examination,4 of the cases were diagnosed as smallcell neuroendocrine carcinoma and the other 2 were diagnosedas atypical carcinoid tumor.On immunohistochemical stainingall tumors expressed neuroendocrine markers includingneuronspecific enolase(CD56),synaptophysin(Syn)andchromogranin(CgA).In patients receiving partial cystectomyfollowed by postoperative chemotherapy,relapse was found in 4of the 6 cases on follow up.CONCLUSION NECB is a rare entity and a tumor with highmalignant potential and characteristic pathologic features.Hematuria is the cardinal symptom of NECB.Metastasis mayoccur at an early stage and the prognosis of the disease is poor.Final diagnosis of NECB depends on histopathologic examinationand immunohistochemical assays.Surgical excision combinedwith radiotherapy and chemotherapy is considered an effectivetreatment.