Comparative immunohistochemical evaluation between primary and metastatic lesion in a feline osteosarcoma - A case report

Feline primary bone tumors are rare. Still, osteosarcoma (OSA) composes almost 80 % of malignant bone tumors in cats, affecting mostly elder feline individuals. Many differences are observed between canine and feline OSA regarding radiographic image and tumoral behavior, especially metastasis development. This case reports a cat diagnosed with digital osteosarcoma who developed pulmonary metastasis and other digital lesions over one year and half later. Simultaneous immunohistochemical analysis from both primary and metastatic tumoral tissues was performed using diagnostic and prognostic biomarkers panel for bone tumors in order to better understand such aggressive behavior in a feline patient. Similarities and differences from both lesions results revealed intrinsic mechanisms promoting osteosarcoma invasion in this cat.