Bladder, ureter & renal pelvis
Neuroendocrine neoplasms
Well differentiated neuroendocrine tumor


Topic Completed: 1 December 2014

Minor changes: 11 June 2020

Copyright: 2003-2020, PathologyOutlines.com, Inc.

PubMed Search: Bladder carcinoid tumor

Turki Al-Hussain, M.D.
Page views in 2019: 612
Page views in 2020 to date: 569
Cite this page: Al-Hussain T. Well differentiated neuroendocrine tumor. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/bladdercarcinoid.html. Accessed September 30th, 2020.
Definition / general
  • Rare low grade neuroendocrine carcinoma, similar to counterparts at other sites
  • Formerly called carcinoid tumor
Epidemiology
  • Usually ages 47-69 years
Sites
  • Bladder neck and trigone
Etiology
Clinical features
  • Rare, < 50 cases described
  • Patients present with hematuria
  • No carcinoid syndrome
  • Behavior is difficult to predict (Arch Pathol Lab Med 2006;130:1693); occasionally produces metastases and death
Case reports
Treatment
  • Excision is usually curative, but behavior may not be predictable
Gross description
  • Usually 1-2 cm
  • Smooth-surfaced sessile polypoid nodules covered by urothelium
Microscopic (histologic) description
Microscopic (histologic) images

Images hosted on other servers:
Missing Image

Various images

Positive stains
Electron microscopy description
  • Neuroendocrine differentiation
Differential diagnosis
  • Inverted papilloma: lacks salt and pepper chromatin of carcinoid tumors; not invasive
  • Metastasis: clinical history
  • Nested variant of urothelial carcinoma: classic urothelial carcinoma usually present elsewhere; usually no well defined neuroendocrine features
  • Paraganglioma: nests of tumor cells surrounded by S100+ sustentacular cells
  • Direct invasion of carcinoid tumor from appendix: clinical history
Back to top
Image 01 Image 02