Premium
Special AT ‐rich sequence‐binding protein 2 ( SATB 2) expression is sensitive but may not be specific for osteosarcoma as compared with other high‐grade primary bone sarcomas
Author(s) -
Davis Jessica L,
Horvai Andrew E
Publication year - 2016
Publication title -
histopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.626
H-Index - 124
eISSN - 1365-2559
pISSN - 0309-0167
DOI - 10.1111/his.12911
Subject(s) - osteosarcoma , leiomyosarcoma , sarcoma , osteoid , pathology , immunohistochemistry , biopsy , medicine , tissue microarray , primary bone , bone sarcoma , cancer research
Aims The diagnosis of osteosarcoma, although important for eligibility in clinical trials and proper therapy, may be challenging when no bone or osteoid matrix is identified on biopsy. Therefore, other adjunct tests have been sought to help confirm the diagnosis. Special AT ‐rich sequence‐binding protein 2 ( SATB 2) has been shown as a reliable marker of osteoblastic differentiation. The aim of this study was to examine SATB 2 expression in osteosarcomas and other primary bone sarcomas, in order to evaluate its diagnostic utility in discriminating osteogenic from non‐osteogenic sarcomas. Methods and results Forty‐eight pretreated osteosarcoma biopsies, including 26 whole‐section cases and 22 tumours on tissue microarrays, and 36 non‐osteogenic bone sarcomas were evaluated. Forty‐five of 48 (94%) osteosarcomas showed nuclear immunoreactivity for SATB 2 (all whole‐slide sections showed expression). Positive SATB 2 expression was observed in 11 of 22 (50%) undifferentiated pleomorphic sarcomas ( UPS s), and in five of 11 (45%) fibrosarcomas; expression was absent in two pleomorphic rhabdomyosarcomas and in the one leiomyosarcoma. The sensitivity of SATB 2 for osteosarcoma was 94%, and the specificity was 55%. Stronger‐intensity staining was observed in osteosarcoma ( P < 0.0001). Conclusions SATB 2 is a sensitive marker for osteosarcoma; however, it is not specific, with expression being observed in other high‐grade primary bone sarcomas. Intriguingly, the lack of specificity may suggest that the undifferentiated sarcomas ( UPS s and fibrosarcomas) with SATB 2 expression actually represent osteosarcomas that produce too little matrix to be detected with routine sampling or consist of osteoblast precursors that do not synthesize matrix.