Other malignancies
Synovial sarcoma

Authors: Kenneth Iczkowski, M.D. (see Authors page)

Revised: 24 August 2017, last major update March 2017

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

PubMed search: prostatic synovial sarcoma

Cite this page: Iczkowski, K. Synovial sarcoma. website. Accessed April 21st, 2018.
Definition / general
Essential features
  • Spindle and oval cells forming interlacing fascicles
  • Aggressive growth and metastasis common
  • Age range of 28 to 63 years
  • Reportedly established on a core needle biopsy in 1 case and transurethral resection of the prostate in a second; in 8 other cases, on resection
Case reports
  • Combinations of surgical resection, chemotherapy or radiation therapy
  • Surgical procedures range from radical prostatectomy to pelvic extenteration with en bloc penectomy and pubectomy
Microscopic (histologic) description
  • Uniform spindle and oval cells forming interlacing fascicles resembling fibrosarcoma
  • Focally the compact fascicles of tumor cells alternate with hypocellular myxoid tissue resembling peripheral nerve sheath tumors
  • Focal pericytomatous pattern of polygonal cells arranged around dilated, thin walled blood vessels
Microscopic (histologic) images

Images hosted on PathOut server, contributed by Dr. Kenneth Iczkowski:

A cellular pattern of overlapping uniform spindle and oval cells
forming interlacing fascicles is evident in this needle biopsy.
Pericytomatous cell arrangement was not prominent

Images hosted on other servers:

Site unspecified

Positive stains
Molecular / cytogenetics description
Differential diagnosis
Board review question #1
Which of the following stains when positive helps confirm synovial sarcoma:

  1. CD34
  2. CD99
  3. Cytokeratin 20
  4. Desmin
  5. Calretinin
Board review answer #1
B. CD99