Prostate gland & seminal vesicles

Stromal tumors

Stromal sarcoma

Editorial Board Member: Debra L. Zynger, M.D.
Kenneth A. Iczkowski, M.D.

Topic Completed: 1 June 2017

Minor changes: 26 January 2022

Copyright: 2003-2022,, Inc.

PubMed search: Prostatic stromal sarcoma

Related topics: Stromal proliferation of uncertain malignant potential

Kenneth A. Iczkowski, M.D.
Page views in 2021: 1,448
Page views in 2022 to date: 104
Cite this page: Iczkowski KA. Stromal sarcoma. website. Accessed January 28th, 2022.
Definition / general
  • A rare entity (Pathology 2013 Feb;45:104)
  • Usually presents with urinary retention; also abnormal digital rectal examination, hematuria or hematospermia, palpable rectal mass
  • Includes phyllodes tumors (like those of the breast)
Essential features
  • Cellular pleomorphism exceeding that of stromal proliferation of undetermined malignant potential
  • Necrosis
  • Mitotic activity
  • Extension outside the prostate
ICD coding
  • C61 Malignant neoplasm of prostate
Clinical features
  • The most common presentation is bladder outlet obstruction, followed by abnormal digital rectal exam, hematuria and rectal fullness (Am J Surg Pathol 2006;30:694)
  • Serum PSA is usually normal
Radiology description
  • MRI shows a multinodular mass with homogeneous or heterogeneous low signal intensity on T1 weighted imaging and heterogenous high signal intensity on T2 weighted imaging (Oncol Lett 2016;11:2542)
Radiology images

Images hosted on other servers:

T1-weighted axial MRI image

T2-weighted axial MRI image

Prognostic factors
Case reports
Microscopic (histologic) description
  • Greater cellularity, mitotic activity, necrosis and stromal overgrowth than stromal tumor of uncertain malignant potential
  • Storiform and infiltrative growth pattern
  • Sarcomas are subdivided into low grade and high grade based on mitotic rate, necrosis and degree of atypia (Am J Surg Pathol 2006;30:694)
  • There may be either stromal elements with benign glands resembling malignant breast phyllodes tumors or pure stromal elements
Microscopic (histologic) images

Images hosted on other servers:

Various images

Histological features

Positive stains
Negative stains
Molecular / cytogenetics description
  • Both prostatic stromal sarcoma (all 4 cases) and smooth muscle tumors of uncertain malignant potential (STUMP) (7 of 8 cases) share chromosomal aberrations by array comparative genomic hybridization (aCGH); most common was loss of chromosome 13 followed by losses of chromosomes 14 or 10; thus, sarcoma and STUMP are in the same family of tumors and aCGH is not discriminatory (Mod Pathol 2013;26:1536)
Differential diagnosis
Board review style question #1
Two of the most consistently positive and useful markers for prostatic stromal sarcoma are:

A. Estrogen receptor and CD34
B. S100 protein and HHF35 muscle marker
C. CD34 and progesterone receptor
D. Desmin and S100 protein
E. Smooth muscle actin and estrogen receptor
Board review style answer #1
C. CD34 and progesterone receptor

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Reference: Stromal sarcoma
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