Mandibular squamous cell carcinoma in 2 psittacines

Abstract

A unilateral, malformed gnathotheca in a green-winged macaw ( Ara chloropterus) was managed for 16 mo with periodic beak trims. Biopsy of the affected beak did not identify an underlying cause; however, at postmortem examination, a densely cellular neoplasm invaded the mandible from the beak, dissecting and effacing the cortex and trabecular bone and inciting periosteal proliferation. There was no evidence of metastasis. Neoplastic cells were strongly immunopositive for cytokeratin AE1/AE3, consistent with squamous cell carcinoma (SCC). A black-headed caique ( Pionites melanocephalus) was presented with a similar clinical history, timeline, and gross appearance. Biopsy of the mandibular portion of the lesion resulted in a diagnosis of SCC. Medical management with toceranib at a palliative dose resulted in adverse side effects and was discontinued. Early diagnosis of mandibular SCC may allow for early intervention and development of treatment modalities. Our 2 cases suggest that the mandibular bone, not the beak, may be a preferred biopsy site in the diagnosis of mandibular SCC in psittacines.

Squamous cell carcinoma of the footpad with systemic metastasis in a captive crowned solitary eagle (<i>Buteogallus coronatus</i>)

“…In birds, a variable degree of keratinization, invasion of the adjacent tissues, and metastasis have been reported in SCCs in different body locations [ 9 , 11 , 12 , 16 ]. The cytoplasm of neoplastic cells in the footpad was strongly positive for cytokeratin (CK), a remarkable feature also observed in SCCs in the foot of a pink-backed pelican [ 14 ] and in the mandible of two psittacines [ 7 ].…”

Alimentary squamous cell carcinoma in psittacines: 12 cases and review of the literature

“…2,11,40 There are a few, scattered reports of alimentary SCC in psittacines that include an ingluvial SCC in a cockatiel, mandibular SCCs in a green-winged macaw ( Ara chloropterus ), a black-headed caique ( Pionites melanocephalus ) and a Buffon’s macaw ( Ara ambigua ), and esophageal SCCs in 2 Amazon parrots ( Amazona aestiva and Amazona farinosa ). 10,18,19,35 Retrospective reviews of case submissions to veterinary diagnostic laboratories also revealed a low prevalence of these neoplasms, including cases of oral SCC in an unspecified psittacine and in a red-shouldered macaw ( Diopsittaca nobilis ). 6,10,26…”

“…10,18,19,35 Retrospective reviews of case submissions to veterinary diagnostic laboratories also revealed a low prevalence of these neoplasms, including cases of oral SCC in an unspecified psittacine and in a red-shouldered macaw ( Diopsittaca nobilis ). 6,10,26…”

“…The species distribution in the cited large-scale clinical survey 42 and other studies 18,24,35 matches the findings of our case series, with Amazon parrots and cockatiels significantly overrepresented compared to other psittacines. 10,42…”

“…1–4,6,7,9,12–16 SCCs in birds can occur in any location, typically in rostral mucocutaneous junctions, uropygial gland, choana, distal wing (phalanges and patagium) and, less commonly, the alimentary tract. 3,9,10,19,26 Compared to their integumentary counterparts, alimentary SCCs are poorly studied in terms of specific location, gross and histopathologic features. We present here a retrospective study of 12 alimentary SCCs in psittacines and a review of the literature.…”