COMPUTED TOMOGRAPHIC FINDINGS IN 24 DOGS WITH LIPOSARCOMA

Computed tomography (CT) continues to become more widely available for assessment of tumors in dogs, yet there are no studies describing the CT appearance of canine liposarcomas. In this retrospective, multicenter study, CT images of dogs with histologically confirmed liposarcomas were reviewed for size, location, attenuation, contrast enhancement, border definition, internal homogeneity, local infiltration, and mineralization. A total of 24 dogs with 26 liposarcomas were sampled. Mean attenuation was +15.2 (SD = 22.3) Hounsfield units (HU) with a range of -36 to +47.5 HU based on representative regions of interest. Twenty tumors (77%) contained focal areas of fat attenuation. All masses enhanced with contrast medium administration, which is distinct from what has been reported previously in infiltrative lipomas. Other CT features associated with canine liposarcomas included heterogeneous internal attenuation (81%) and lack of a clearly defined capsule (38%) suggesting infiltration of local structures. Six tumors (23%) had foci of mineralization. Findings from the current study indicated that liposarcoma should be considered as a differential diagnosis for mixed-attenuation, contrast-enhancing masses in dogs that contain at least one focus of fat attenuation on precontrast images; however, presence of foci of fat attenuation was not a necessary finding for the diagnosis of canine liposarcoma.