Soft tissue
Other tumors
Synovial sarcoma

Author: Vijay Shankar, M.D. (see Authors page)

Revised: 15 September 2016, last major update November 2012

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

PubMed Search: Synovial sarcoma [title] soft tissue

Related topics: Calcifying synovial sarcoma
Definition / General
  • Usually a deep seated mass present for years around large joints (80% in knee and ankle) in young adults (age 20-40), 60% male; only 10% actually involve the joint
  • Represent 10% of adult soft tissue tumors
  • 5 year survival is 50 - 70%; 10 year survival 40%; recurs locally, 10 - 15% metastasize to lung and pleura, bone, regional nodes
  • Rarely radiation associated (Mod Pathol 2002;15:998)
  • Minute (< 1 cm) tumors of hands and feet: 2/3 female, median age 29 years, 2/3 monophasic, 40% have microcalcifications; EMA+, keratin+; have clinically favorable course if completely excised (Am J Surg Pathol 2006;30:721)
Prognostic Factors
Case Reports
Treatment
  • Wide local excision plus radiation
Clinical Images
Images hosted on PathOut server:

MRI, courtesy of Dr. Mark R. Wick

Foot, courtesy of Dr. Mark R. Wick

Gross Description
  • Well circumscribed, firm, gray - pink
  • Focal calcifications on Xray
  • Rarely within major nerves
Gross Images
Images hosted on PathOut server:

Cystic changes, courtesy of Dr. Mark R. Wick



Images hosted on other servers:

14 cm mediastinal mass

Buttock mass

Mandibular region

Micro Description
  • Biphasic, monophasic or undifferentiated
  • Biphasic have spindle cells resembling synoviocytes and plump epithelial cells forming glands / cords
  • Monophasic lack the epithelial cells
  • Spindle cells are arranged in plump fascicles with hyalinization and distinct lobulation accompanied by mast cells, occasional osseous or cartilaginous metaplasia, focal whorling
  • May have hemangiopericytomatous vascular pattern
  • Poorly differentiated histology predicts poor outcome
Micro Images
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Images hosted on PathOut server:

Images courtesy of Dr. Mark R. Wick:

Staghorn blood vessels

Hemangiopericytoid

Nuclear palisading

Small cell


Monophasic spindle cell

Monophasic epithelioid


Biphasic

Biphasic pseudoglandular

Intranuclear TLE1

CD99



Images hosted on other servers:

Epithelial islands

Spindled cells

Connective tissue

Biphasic vs monophasic

Breast-supraareolar

Buttock


Radiation associated

Various images

Keratin+

Vimetin+

Positive Stains
Negative Stains
Electron Microscopy Description
  • Glandular formation of epithelioid tumor cells with sparse luminal microvilli
Electron Microscopy Images
Images hosted on PathOut server:

Biphasic, courtesy of Dr. Mark R. Wick

Biphasic spindle cell, courtesy of Dr. Mark R. Wick

Molecular / Cytogenetics Description
Molecular / Cytogenetics Images
Images hosted on PathOut server:

X18, in situ hybridization, courtesy of Dr. Mark R. Wick

Courtesy of Dr. Mark R. Wick



Images hosted on other servers:

SYT-SSX, SYT-SSX1, and SYT-SSX2

Differential Diagnosis