Pathologists face difficulty in accurately and consistently differentiating osteosarcoma (OSA) from other types of neoplasms using only histopathology. Due to malignant osteoblasts having markedly pleomorphic phenotypes and variable amounts of tumor-associated matrix, the limited sensitivity and specificity of current immunohistochemical markers for animals only provide inconsistent results.

The researchers co-authored the study to determine if the immunohistochemical marker known as special AT-rich sequence-binding protein 2 (SATB2) can be useful for diagnosing canine OSA by assessing its sensitivity and specificity in identifying normal and neoplastic canine osteoblasts and distinguishing them from other types of neoplasms. StageBio Research Scientist Brian Tabb, MS, HTL, QIHC, established protocols for the IHC staining and contributed to the methods section of this study.

SATB2 was selected for the study because the marker’s immunohistochemistry (IHC) has aided in detecting normal and neoplastic osteoblasts in human beings.
 

Confirming the sensitivity and cross-reactivity of SATB2 for normal and neoplastic canine osteoblasts

In the first phase of the study, the research team performed SATB2 IHC on multiple samples of canine OSA and other tumor types, along with normal tissues, to confirm the marker’s sensitivity and cross-reactivity. Findings from this first phase showed that SATB2 is immunoreactive for normal and neoplastic canine osteoblasts while proving non-immunoreactive for other non-osseous mesenchymal cell types and organs.
 

Evaluating SATB2 IHC as a marker for identifying canine OSA

Once the immunoreactivity of SATB2 was confirmed, the researchers then tested SATB2 IHC on more than 120 cases of poorly differentiated malignant neoplasms. This testing was done as part of a panel that consisted of other appropriate immunohistochemical markers.
 

Access the study to learn the results

At the study’s conclusion, the researchers concluded that SATB2 IHC is a proven sensitive and specific marker useful in the identification of canine OSA.

To learn more about the study’s methods and findings, access the full study, “Special AT-rich sequence-binding protein 2 immunohistochemistry in the diagnosis of osteosarcoma in dogs,” from the Journal of Comparative Pathology.