Squamous-cell carcinoma on the legs of an Aracauna chicken.

Squamous-cell carcinoma was diagnosed on both legs of a 6-year-old pet Aracauna chicken. Grossly, the tumors were raised and horny with superficial ulceration. Histologically, the tumors were highly invasive, extending deep into the dermis, tendon sheaths, and periosteal tissues. There was no evidence of vascular invasion or metastasis to other organs.