Clinical features, treatment, and outcomes of cutaneous and oral squamous cell carcinoma in avian species

Abstract

OBJECTIVE To determine the clinical features, treatment, and outcomes of treatment for oral and cutaneous squamous cell carcinoma (SCC) in avian species. DESIGN Retrospective case series with nested cohort study. ANIMALS 87 client-owned birds of various species with histologically confirmed SCC of the skin or oral cavity. PROCEDURES Clinicians entered case information through an online survey tool. Data were collected regarding patient signalment, concurrent conditions, treatments, adverse effects, and clinical outcomes. Relationships were examined between complete excision and partial or complete response. Survival analysis was performed to compare outcomes among groupings of therapeutic approaches. RESULTS Only 7 of 64 (11%) birds for which full outcome data were available had complete remission of SCC; 53 (83%) had progressive disease, were euthanized, or died of the disease. The unadjusted OR for partial or complete response following complete tumor excision (vs other treatment approaches) was 6.9 (95% confidence interval [CI], 1.8 to 25.8). Risk of death was 62% lower (hazard ratio, 0.38; 95% CI, 0.19 to 0.77) for birds that underwent complete excision versus conservative treatment. Median survival time from initial evaluation for birds receiving complete excision was 628 days (95% CI, 210 to 1,008 days), compared with 171 days (95% CI, 89 to 286 days) for birds receiving monitoring with or without conservative treatment. Birds receiving any other additional treatment had a median survival time of 357 days (95% CI, 143 to 562 days). CONCLUSIONS AND CLINICAL RELEVANCE For birds with SCC, complete excision was the only treatment approach significantly associated with complete or partial response and increased survival time.

The use of a 3D-printed prosthesis in a Great Hornbill (Buceros bicornis) with squamous cell carcinoma of the casque

“…Squamous cell carcinoma of the casque is regularly reported in this hornbill species, and medical treatment is usually unrewarding [11,13]. As complete excision was the only treatment significantly associated with complete or partial response and increased survival in a retrospective study of squamous cell carcinomas in birds [14], resection of affected tissue including the casque rhinotheca and underlying maxillary bone was the preferred treatment option in this case. However, planning and performing radical resection accurately, and preventing post-operative complications is a challenge.…”

Mandibular squamous cell carcinoma in 2 psittacines

“…Squamous cell carcinomas (SCCs) are relatively uncommon in avian species but are reported most frequently in cockatiels, Amazon parrots, conures, and budgerigars. 4,14 Fewer cases of SCC are reported in poultry, hornbills, storks, eclectus parrots, and macaws. 1,2,[5][6][7]12,13 SCCs in birds typically arise from single or multiple sites in the skin, mucocutaneous junctions, uropygial gland, and upper gastrointestinal tract.…”

“…14 Pet birds are commonly fed seed-based diets, which are deficient in vitamin A, leading to hypovitaminosis A and squamous metaplasia of the upper digestive tract, which may progress to SCC if the condition is chronic and not corrected. 8,10,14 Although it is possible that the birds in our report may have had historic vitamin A deficiency and squamous metaplasia of the upper digestive tract mucosa and salivary glands, this is speculative and neither were identified clinically or at postmortem examination. Although dietary changes were implemented at the initial presentation of the macaw with the goal to provide balanced nutrition and facilitate food prehension, neoplastic transformation may have already occurred.…”

“…It is also possible that the initial wound represented a chronic infection and inflammatory process that initiated malignant transformation as the disease progressed, although this is considered less likely given the lack of infectious processes diagnosed clinically or at postmortem examination. 14 Similarly, chronic, persistent trauma and wounds may predispose to SCC and could have contributed to neoplastic transformation, although there was no indication of trauma in the clinical history.…”

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

“…Regurgitation, dysphagia, or observation of an oral mass were common clinical complaints in our study as well as in the literature. 42 In alimentary SCC cases, especially in those affecting the crop, dysphagia can be attributed to either reduction of the ingluvial and/or esophageal lumina because of the physical presence of a mass, or it might have a neurogenic cause if atony of the upper digestive tract occurs as a result of invasion of parasympathetic nerve branches. 18 Dilation of the crop might also prompt consideration of proventricular dilation disease, which is caused by avian bornavirus infection.…”