Histology Course S IX 17 Department of Pathology, University of Zurich Histology Course

S IX 17 synovial sarcoma, biphasic  HE  
  ICD-10: C38.4; ICD-O: 9043/3  
 


32-year-old female, with swelling of the soft tissue at the shoulder area, slowly increasing over months. Biopsy.

- Cell-dense tumour tissue consisting of two heterogenous mixed components:
1. densely arranged spindle cells with elongated, dense nuclei and mitotic activity
2. epithelioid cell clusters often with formation of glandular structures with intraluminal secretion
- areas of collagenisation, possibly calcification.


Comment:
The two mentioned components are the reason for the term biphasic. Immunohistochemically expressed is the spindle cell component Vimentin, occasionally also cytokeratine, predominantly the epithelioid type. So-called monophasic synovial sarcomas are only spindle-cell shaped and more difficult to recognize since they do not always express cytokeratin.