Cutaneous Xanthoma in a Dog

Abstract

A 2-year-old, 12.5 kg, castrated male, mixed-breed dog was presented with a 1-year history of pruritus and progressive alopecia. On physical examination, no remarkable findings were detected including body condition score (5/9). A dermatological examination of the dog revealed generalized erythema, papules or plaques, especially on the face, auricle, dorsum, and shoulder. A fine-needle aspiration of the dorsum and face lesions revealed various numbers of macrophages with foamy cytoplasm and multinucleated giant cells. A bacterial culture test showed the growth of Staphylococcus pseudintermedius. A complete blood cell count was unremarkable and biochemical abnormalities included hyperglobulinemia (4.8 g/dL, reference interval 2.5-4.5 g/dL), mild hypertriglyceridemia (277 mg/dL, reference interval 10-100 mg/dL) and mild hypercholesterolemia (383 mg/dL, reference interval 110-320 mg/dL). Additional diagnostic tests were performed to identify the underlying cause of hyperlipidemia. Canine pancreatic lipase immunoreactivity (<50 ng/mL, reference interval 0-200 ng/mL) and total T4 (1.4 µg/dL, reference interval 1.1-5.6 µg/dL) were within the reference intervals. For a definitive diagnosis, skin biopsy specimen was collected from the papular lesions on the dorsum by using a 4 mm biopsy punch. A histopathological examination revealed numerous large macrophages with abundant foamy cytoplasm in the dermis. The foamy macrophages were located diffusely between the collagen fibers. Extracellular amorphous lipid deposits were also presented in the dermal tissue. A definitive diagnosis of cutaneous xanthoma was made based on clinical signs and cytological and histopathological results.