An invasive primary nasal histiocytic sarcoma in a cat

This article reports an approximately 4-year-old, female, spayed cat with an invasive nasal histiocytic sarcoma, which was diagnosed by histopathology and immunohistochemical staining with several markers. Following cytologic evaluation, lymphoma was suspected. Histopathology and immunohistochemistry were required to reach a diagnosis. The tumour presented an expansile invasion pattern under head computed tomography. L-asparaginase was prescribed before the immunohistochemical confirmation, but the response was undetermined.