Apocrine adenocarcinoma in Oryctolagus cuniculus (domestic rabbit) with osteolysis: case report

ABSTRACT: Apocrine adenocarcinoma is a malignant tumor arising from the apocrine gland. It’s well-reported in dogs, uncommon in cats, and rarely described in other species. A 4-year-old female domestic rabbit with lameness in the left pelvic limb, which progressed to loss of function over seven months, was treated in a medical routine. Upon palpation of the affected region, the rabbit presented alertness without exhibiting painful sensitivity. Radiographic imaging revealed pronounced alterations in the bone trabeculae of the left femur, accompanied by areas of corticomedullary osteolysis. A biopsy from the left femur was performed for histopathological and immunohistochemical analysis. The morphological diagnosis comprises apocrine adenocarcinoma. This report aims to present what seems to be the first worldwide case of apocrine adenocarcinoma invading muscle tissue and causing bone lysis in the joint region in an Oryctolagus cuniculus.