title: Primary carcinoid tumors of the kidney.
abstract: OBJECTIVE
  We describe in detail the features of carcinoid tumors of the kidney. We evaluated possible prognostic factors.
  
  
  METHODS
  An extensive search was performed in the medical literature regarding primary carcinoid tumors of the kidney. Epidemiological, clinical, diagnostic, histopathological, therapeutic and prognostic data were evaluated. Several potential risk factors were compared with the incidence of metastases and clinical outcome of the patients.
  
  
  RESULTS
  A total of 56 case reports were reviewed. Median patient age was 49 years. Horseshoe kidneys were present in 17.8% of cases. Incidental diagnosis was made in 28.6% of patients. The most common symptom was abdominal or flank pain and neuroendocrine syndromes occurred with only 12.7% of primary renal carcinoid tumors. Of the patients 73.6% presented with tumors larger than 4 cm. Metastases were present in 45.6% of patients at initial diagnosis and almost 60% with tumors greater than 4 cm had metastases.
  
  
  CONCLUSIONS
  Renal carcinoid is the second most prevalent genitourinary carcinoid in each sex, following testicular carcinoids in men and ovarian tumors in women. Significant adverse prognostic factors include age greater than 40 years, tumor size greater than 4 cm, purely solid tumors on the cut surface, mitotic rate higher than 1/10 high power fields, metastasis at initial diagnosis and tumors extending throughout the renal capsule.
authors.affiliation: James Buchanan Brady Urological Institute, The Johns Hopkins Medical Institutions, 600 North Wolfe Street, Baltimore, MD 21287, USA. frederico.romero@gmail.com
authors.forename: Frederico R
authors.initials: FR
authors.lastname: Romero
authors.forename: Soroush
authors.initials: S
authors.lastname: Rais-Bahrami
authors.forename: Sompol
authors.initials: S
authors.lastname: Permpongkosol
authors.forename: Samson W
authors.initials: SW
authors.lastname: Fine
authors.forename: Sahar
authors.initials: S
authors.lastname: Kohanim
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Jarrett
mesh_terms: D002114:Calcinosis; D002276:Carcinoid Tumor / Q000175:diagnosis / Q000473:pathology / Q000601:surgery; D005765:Gastrointestinal Agents; D006801:Humans; D007668:Kidney / Q000002:abnormalities; D007680:Kidney Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000601:surgery; D008875:Middle Aged; D009367:Neoplasm Staging; D009392:Nephrectomy; D015282:Octreotide; D015995:Prevalence; D011379:Prognosis; D012307:Risk Factors
chemical_list: D005765:Gastrointestinal Agents; D015282:Octreotide