Other malignancies
Synovial sarcoma

Author: Hanni Gulwani, M.D. (see Authors page)

Revised: 22 June 2018, last major update December 2012

Copyright: (c) 2003-2018,, Inc.

PubMed Search: Synovial sarcoma mediastinum

Cite this page: Gulwani, H. Synovial sarcoma. website. Accessed July 19th, 2018.
Definition / general
  • Primary synovial sarcoma is rare; presents as anterior mediastinal mass with chest pain, shortness of breath, pleural effusion
  • Usually paravertebral location in posterior mediastinum
  • Aggressive behavior with local recurrence / metastases to lung, lymph nodes, epidural space (Am J Surg Pathol 2005;29:569)
Gross description
  • 5 - 20 cm, tan-white, soft to rubbery cut surface with hemorrhage, necrosis, gelatinous material
  • May show cystic degeneration
  • May be well circumscribed or grossly invade chest wall, great vessels, heart, pericardium, pleura, rib, vertebra
Microscopic (histologic) description
  • Biphasic with well formed glandular elements admixed with monotonous atypical spindle cells
Electron microscopy description
  • Oval to spindle tumor cells with closely apposed cell membranes, abundant cytoplasmic intermediate filaments and rough endoplasmic reticulum and immature desmosome type cell junctions
Differential diagnosis
  • Other biphasic and monophasic spindle cell neoplasms