Bladder
Other tumors
Osteosarcoma

Author: Gillian Levy, M.D. (see Authors page)

Revised: 8 August 2016, last major update December 2014

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

PubMed Search: Bladder osteosarcoma
Definition / General
  • Malignant mesenchymal tumor with osteoid formation
Epidemiology
  • Sarcomas comprise < 1% of malignant bladder tumors
  • Rare; < 50 cases reported
  • 80% male
  • Mean age 64 years, range 41 to 86 years
Sites
  • Usually trigone
Etiology
  • Patients may have prior or simulataneous urothelial carcinoma
Clinical Features
  • Associated with urinary tract schistosomiasis
  • Patients present with hematuria, urgency and dysuria
Prognostic Factors
  • Poor prognosis
  • Most patients die within 6 months due to local spread with urinary tract obstruction and secondary infection
Case Reports
Treatment
  • Radical cystectomy, radiation and chemotherapy
  • Occasionally responsive to radiotherapy and chemotherapy
Gross Description
  • Large, polypoid, infiltrative, often gritty tumor
Gross Images

Images hosted on other servers:
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24 year old woman

Micro Description
  • High grade sarcoma with spindle cells showing marked pleomorphism; no definite carcinomatous component
  • Abundant lace-like osteoid
  • May have chondroid matrix in background
Micro Images

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Hypercellular tumor

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Various images; keratin negative but p53 positive

Cytology Description
  • Spindle cell lesion with marked nuclear pleomorphism
Positive Stains
Differential Diagnosis