Immunoreactivity of Canine Liposarcoma to Muscle and Brown Adipose Antigens.
Liposarcoma, rhabdomyosarcoma, and hibernoma share some overlapping histologic and immunohistochemical features. Although immunohistochemistry (IHC) is commonly used in the diagnosis of these neoplasms, expression of muscle markers has been reported in human liposarcoma and canine hibernoma in addition to rhabdomyosarcoma. Thus, these neoplasms are a diagnostic challenge but important to distinguish because of differences in prognosis and treatment. Rhabdomyosarcoma and liposarcoma are both malignant, but rhabdomyosarcoma has a higher potential for metastasis. In contrast, hibernomas are benign with low risk of recurrence. This study investigated expression of the muscle markers desmin, myogenin, and α-smooth muscle actin (α-SMA) and the brown fat marker uncoupling protein 1 (UCP1) in 25 cases of canine liposarcoma using IHC. Oil red O histochemistry was performed to confirm the presence of lipid and the diagnosis of liposarcoma in cases that were not well-differentiated. The 25 cases included 15 well-differentiated, 5 pleomorphic, 3 myxoid, and 2 dedifferentiated subtypes of liposarcoma. By IHC, 23 of 25 expressed UCP1, 7 of 25 expressed α-SMA, 7 of 25 expressed desmin, and 3 of 25 expressed myogenin with no clear relationship of antigen expression and tumor subtype. These findings clarify the immunohistochemical profile of canine liposarcoma and suggest overlap in the expression of several muscle antigens and UCP1 between liposarcoma, hibernoma, and rhabdomyosarcoma.
['LaDouceur|Elise E B|EEB|', 'Stevens|Sarah E|SE|', 'Wood|Jason|J|', 'Reilly|Christopher M|CM|']
D000199:Actins D002001:Adipose Tissue, Brown D000818:Animals D000941:Antigens D014408:Biomarkers, Tumor D003893:Desmin D004283:Dog Diseases D004285:Dogs D005260:Female D007150:Immunohistochemistry D008080:Liposarcoma D008297:Male D009130:Muscle, Smooth D018008:Myogenin D000071256:Uncoupling Protein 1
liposarcoma immunohistochemistry desmin myogenin α-smooth muscle actin uncoupling protein 1 dog neoplasia