Infiltrative Lipoma -- In a Bird

This article describes the first documented case of an infiltrative lipoma in a bird. The case involves a 14-year-old, blue-crowned conure of unknown sex that was obtained by the owners as a hatchling from a pet store. The conure lives with 7 other birds but does not have direct contact with them. The bird was presented after a 3-week period of straining to defecate and vocalizing during defecation. Physical examination revealed the following abnormalities: a 2.5-cm diameter subcutaneous soft tissue swelling on the midline of the caudoventral abdomen. The feathers around the cloaca were stained with urates and blood. The cloaca mucosa was hyperemic, edematous, and friable. Blood analysis revealed an increase in creatine kinase and sodium. Polymerase chain reaction assays for avian Polyomavirus and psittacine beak and feather disease antigen were negative. The bird underwent exploratory surgery and a mass extending through the body wall musculature and entering the coelomic cavity was dissected and removed; after removal of the mass, the cloaca returned to its normal position. The histopathologic diagnosis was an infiltrative lipoma. Soon after surgery, the clinical signs resolved and the bird was still doing well 7 months later.

COMMENTARY: Infiltrative lipoma (previously referred to as lipomatosis) is a condition characterized by abnormal localized, or tumor-like, accumulation of fat in the tissues. The condition has previously been reported in cats, dogs, cows, horses, reptiles, and humans, but never in birds.Based on the physical examination and clinical signs seen in this bird, there were many differential diagnoses, such as a subcutaneous or intracoelomic mass, hemangioma, hemangiosarcoma, xanthoma, fibroma, adenocarcinoma, and dystocia. This case report provides another differential for a bird that presents for straining to defecate and also has subcutaneous swelling.

Infiltrative lipoma in a blue-crowned conure (Aratinga acuticaudata). Mehler SJ, Briscoe JA, Hendrick MJ, Rosenthal KL. J AVIAN MED SURG 21:146-149, 2007.