Synovial sarcoma, monophasic fibrous and poorly differentiated

Intrathoracic synovial sarcomas show a high proportion that are poorly differentiated.

Immunohistochemistry

The diagnoses in publications1&4 were proven by the presence of the translocation t(X:18)(p11.2;q11.2).

 

monophasic fibrous

poorly differentiated

  

AE1/AE3

33/471, 0/14

6/131

only one poorly differentiated tumour was negative for all three markers

pancytokeratin KL1

23/471

5/131

EMA

47/471, 1/14

12/131

Cytokeratin 1

5/463

 

  

Cytokeratin 5/6

0/243

0/93

  

Cytokeratin 7

46/713

9/183

  

Cytokeratin 8 / 18

21/463

8/173

  

Cytokeratin 10

0/443

0/183

  

Cytokeratin 13

0/453

0/18

  

Cytokeratin 14

11/403

1/123

  

Cytokeratin 19

41/743

11/183

  

Cytokeratin 20

3/473

0/183

  

E-cadherin

22/471, 8/82

7/131, 2/22

  

coexpression of E-cadherin and KL1

10/471

4/131

  

coexpression of E-cadherin, KL1 and AE1/AE3

8/471

3/131

  

expression of only one of E-cadherin, KL1 and AE1/AE3

10/471

3/131

  

expression of at least one of E-cadherin, KL1 and AE1/AE3

47/601

  

CD34

3/471, 1/14

0/131

  

S-100

18/471, 0/14

3/131

  

SMA

10/471

1/131

  

h-Caldesmon

0/471

0/131

  

Desmin

1/471

0/131

  

bcl-2

43/471

12/131

  

CD99

43/471

13/131

  

CD117

5/471

1/131

  
       

Cytogenetics

Independent of morphology, more than 90% of all synovial sarcomas show the translocation t(X;18)4.

Molecular pathology

Poorly differentiated synovial sarcomas have a distinct profile of gene expression5.

Differential diagnosis

References

1Pelmus, M., L. Guillou, et al. (2002). "Monophasic fibrous and poorly differentiated synovial sarcoma: immunohistochemical reassessment of 60 t(X;18)(SYT-SSX)-positive cases." Am J Surg Pathol 26(11): 1434-40.

2Sato, H., T. Hasegawa, et al. (1999). "Expression of E-cadherin in bone and soft tissue sarcomas: a possible role in epithelial differentiation." Hum Pathol 30(11): 1344-9.

3Chu, P. G. and L. M. Weiss (2002). "Keratin expression in human tissues and neoplasms." Histopathology 40(5): 403-39. (Summary data from multiple papers)

4Cote, J. F., P. P. de Saint-Maur, et al. (2004). "Unusual strong CD34 positivity in a thoracic monophasic fibrous synovial sarcoma." Histopathology 45(5): 539-40.

5 Nakayama R, Mitani S, Nakagawa T, Hasegawa T, Kawai A, Morioka H, et al. Gene expression profiling of synovial sarcoma: distinct signature of poorly differentiated type. Am J Surg Pathol. 2010 Nov;34(11):1599-607.

 

This page last revised 4.12.2010.

©SMUHT/PW Bishop