Skip to
  1. Homepage
  2. Rare diseases
  3. Search
Simple search

Simple search

(*) mandatory field


Other search option(s)

Small cell carcinoma of the bladder

Synonym(s) Poorly differentiated neuroendocrine carcinoma of the bladder
Small cell bladder cancer
Small cell bladder carcinoma
Small cell carcinoma of the urinary bladder
Prevalence <1 / 1 000 000
Inheritance Not applicable
Age of onset Adult
  • C67.0
  • C67.1
  • C67.2
  • C67.3
  • C67.4
  • C67.5
  • C67.6
  • C67.7
  • C67.8
  • C67.9
MeSH -
MedDRA -


Disease definition

Small cell carcinoma of the bladder (SCCB) is a very rare, poorly differentiated neuroendocrine epithelial bladder tumor characterized clinically by hematuria and/or dysuria and a highly aggressive course.


SCCB is extremely rare with an annual incidence of less than 1-9/1,000,000. Since 1980, fewer than 1,500 cases have been identified. The demographic profile of SCCB is similar to that of patients with bladder transitional cell carcinoma (TCC). The majority of patients are male, with a mean sex ratio of 5:1, and a range between 1:1 to 16:1. The vast majority of cases were reported in the Caucasian population.

Clinical description

Most knowledge on SCCB is based on retrospective investigations and on a few prospective studies. Mean age at diagnosis is 67 years (range 32 to 91 years). The clinical features of SCCB are similar to those of bladder TCC and reflect the presence of a tumoral mass. The main symptom is gross hematuria (63 to 88% of cases) with dysuria as the second most common symptom. Urinary obstruction, abdominal pain, urinary tract infection and weigh loss are occasionally present. SCCB often occurs with other types of carcinoma and is frequently found combined with other histological forms of bladder cancer: TCC, adenocarcinoma and squamous cell carcinoma. SCCB is generally believed to have a high metastatic potential. Rare cases of paraneoplastic syndromes such as ectopic ACTH secretion and hypercalcemia have also been reported.


The etiology of the disease is unknown but a multipotent stem cell anomaly is thought to be a likely mechanism. A history of smoking is found in 65% to 79% of cases.

Diagnostic methods

Histology and immunohistochemistry show a tumor that is indistinguishable from small cell lung cancer (SCLC; see this term). Diagnosis of SCCB relies mainly on histopathological data obtained by cystoscopy and transurethral resection of the bladder tumor. Immunochemistry staining is useful in establishing the diagnosis. Light microscopy reveals packed cells having scant cytoplasm containing few organelles. Tumors are composed of nests of small round malignant cells with pyknotic round to oval nuclei and evenly dispersed ''salt and pepper chromatin''. More than 95% of SCCB cases are diagnosed at muscle invasive stage T2 or later.

Differential diagnosis

The differential diagnosis includes direct invasion of the bladder by SCC of the prostate, metastatic SCC from another source, usually the lung, and primary lymphomas of the bladder.

Management and treatment

The staging system used is the TNM-staging of bladder transitional cell carcinoma. Treatment is extrapolated from that of SCLC. However, many patients with SCCB undergo radical resection which is rarely performed in SCLC. Patients with surgically resectable disease should be managed with multimodal therapy associating chemotherapy, surgery and/or radiotherapy. Neoadjuvant chemotherapy using 4 chemotherapy cycles followed by radical cystectomy is the most effective therapeutic sequence. Patients with unresectable disease should be managed with palliative chemotherapy based on neuroendocrine-type regimens comprising a platinum drug (cisplatin in fit patients). Prophylactic cranial irradiation should be considered in stages III/IV bladder SCC.


The prognosis of the disease is poor mainly in the case of pure small cell carcinoma.

Expert reviewer(s)


(*) Required fields.

Attention: Only comments seeking to improve the quality and accuracy of information on the Orphanet website are accepted. For all other comments, please send your remarks via contact us. Only comments written in English can be processed.

Captcha image

Detailed information

Review article
Clinical practice guidelines
Get Acrobat Reader
The documents contained in this web site are presented for information purposes only. The material is in no way intended to replace professional medical care by a qualified specialist and should not be used as a basis for diagnosis or treatment.