Nonurothelial benign tumors
Post-operative spindle cell nodule

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

Revised: 15 June 2016, last major update December 2014

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

PubMed Search: Postoperative spindle cell nodule [title]
Cite this page: Post-operative spindle cell nodule. website. Accessed October 24th, 2016.
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
Micro 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
Micro 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‚Äôs 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
Additional References