Nonurothelial benign tumors
Postoperative spindle cell nodule

Author: Monika Roychowdhury, M.D. (see Authors page)

Revised: 31 July 2017, last major update December 2014

Copyright: (c) 2003-2016,, Inc.

PubMed Search: Postoperative spindle cell nodule [title]
Cite this page: Postoperative spindle cell nodule. website. Accessed October 20th, 2018.
Definition / general
  • Usually women
Clinical features
  • Sometimes incidental
  • May present with hematuria or obstructive voiding symptoms
Prognostic factors
  • Excellent prognosis
Gross description
  • Friable nodule, mean size 1 cm
Microscopic (histologic) description
  • Cellular, fascicular growth pattern of plump or elongated spindle cells which infiltrate the bladder wall and may focally destroy muscle
  • Delicate network of small blood vessels in edematous or myxoid stroma with red blood cell extravasation
  • Ulcerated surface with acute and chronic inflammatory infiltrate
  • May show low to high mitotic activity but no atypical mitotic figures, resembles sarcoma but no atypia
  • No necrosis, no significant pleomorphism
Microscopic (histologic) images

Images hosted on Pathout server:

AFIP fig 2 - 70: interlacing fascicles of myofibroblasts

Uniform cells are mixed with inflammatory cells

Images hosted on other servers:

Left: muscularis propria,
Right: spindle cell nodule

Cytology description
Positive stains
Negative stains
Molecular / cytogenetics description
Differential diagnosis
  • Kaposi sarcoma: no history of recent procedure, primarily a vascular tumor
  • Myxoid leiomyosarcoma: no history of recent procedure; has smooth muscle morphology, pleomorphism, atypical mitotic figures, necrosis