Temporally separated bilateral anal sac gland carcinomas in four dogs

Abstract

Anal sac gland carcinoma arising from the apocrine secretory epithelium in the anal sac wall, is locally invasive and highly metastatic. The majority of anal sac gland carcinomas are unilateral on presentation, but bilateral tumours have been identified. This case series presents the outcome of four unique cases of unilateral anal sac gland carcinoma which subsequently developed contralateral anal sac gland carcinoma 50 to 390 days after removal of the initial tumour. Median survival was 1035 days after initial diagnosis and 807 days after diagnosis of the second anal sac gland carcinoma.

Surgical management of primary, metastatic and recurrent anal sac adenocarcinoma in the dog: 52 cases

“…It is unclear what mechanism underlies staged bilateral ASAC, although epithelial field carcinogenesis has been proposed as an alternative to metastatic disease (Bowlt et al . ). It also remains unclear if lymph node involvement in these cases corresponds to progression of disease from the original site, or develops in association with de novo disease in the contralateral anal sac.…”

Outcome in dogs with advanced (stage 3b) anal sac gland carcinoma treated with surgery or hypofractionated radiation therapy

“…Surgery was described to have a beneficial effect on survival . The role of RT remains poorly defined, with previous studies reporting different protocols consisting of 15 × 3.2 Gy (total dose 48 Gy) for microscopic disease, 4 × 9 Gy (total dose 36 Gy) for microscopic or macroscopic disease or 5 × 4 Gy (total dose 20 Gy) for macroscopic, often inoperable disease . The role of sole or combined modality use of chemotherapy remains unclear .…”

Squamous cell carcinoma of the anal sacs in three dogs

“…, Emms , Bowlt et al . ); they are commonly associated with paraneoplastic hypercalcaemia (in up to 53% of cases) and frequently metastasise (Bennet et al . , Bergman ).…”

“…More recently, Bowlt et al . () suggested that chronic anal sac disease may be a predisposing factor for ASACs. One of the cases reported here suffered from chronic recurrent anal sac infections before the SCC was Diagnosed, and mixed cell inflammation was a consistent finding in the histopathological samples.…”