Hepatoid gland carcinoma
These neuroendocrine tumors are thought to arise from anal sac apocrine secretory epithelium within the perianal glands in response to various carcinogenic compounds, presumably present in fecal content.
These tumors present clinically as perianal swelling and masses in older dogs, with predispostion in Siberian Husky and Shih Tzu breeds. Regional lymphadenopathy may be noted as these tumors may metastasize to sacral and iliac lymph nodes.
Diagnosis requires histological examination of biopsied tissue.
Variant tumor types include nodular hyperplasia, adenoma, epithelioma, differentiated carcinoma and anaplastic hepatoid gland carcinomas.
Histologically, these tumors appear to invade deeply into the underlying perirectal tissue, and vary from solid, rosette, to tubular types but the biological behaviour can be difficult to assess on the basis of the histopathological examination. In these cases, immunohistochemistry may be employed and these carcinomas often stain positively for concanavalin-A.
Hepatoid gland adenomas and epitheliomas are usually resected surgically and rarely recur.
Treatment with hepatoid gland carcinoma usually requires radical wide-margin excision, with adjunct radiation therapy in metastatic cases. Chemotherapy has been trialed with intratumoral bleomycin (1.5 mg/mg) followed by electrotherapy with reasonable success.
Castration of male dogs or estrogen therapy appears ineffective at preventing recurrence.
- Ogawa B et al (2011) Neuroendocrine carcinoma of the apocrine glands of the anal sac in a dog. J Vet Diagn Invest 23(4):852-856
- Goldschmidt MH (1984) Sebaceous and hepatoid gland neoplasms of dogs and cats. Am J Dermatopathol 6(3):287-293
- Isitor GN (1983) Comparative ultrastructural study of normal, adenomatous, carcinomatous, and hyperplastic cells of canine hepatoid circumanal gland. Am J Vet Res 44(3):463-474
- Petterino C et al (2004) Immunohistochemical detection of growth hormone (GH) in canine hepatoid gland tumors. J Vet Med Sci 66(5):569-572
- Gröne A et al (1994) Parathyroid hormone-related protein in normal and neoplastic canine tissues: immunohistochemical localization and biochemical extraction. Vet Pathol 31:308–315
- Simeonov R & Simeonova G (2008) Computer-assisted nuclear morphometry in relation to metastasis to regional lymph nodes in canine hepatoid adenocarcinomas. Anal Quant Cytol Histol 30(6):343-346
- Jakab C et al (2010) Expression of claudin-5 in hepatoid gland biopsies. Vet Dermatol 21(3):276-281
- Castagnaro M et al (1990) Glycoconjugate expression in normal hepatoid glands and hepatoid gland adenomas and carcinomas in dogs. Res Vet Sci 49(3):275-278
- Esplin DG et al (2003) Squamous cell carcinoma of the anal sac in five dogs. Vet Pathol 40(3):332-334
- Martins AM et al (2008) Retrospective - systematic study and quantitative analysis of cellular proliferation and apoptosis in normal, hyperplastic and neoplastic perianal glands in dogs. Vet Comp Oncol 6(2):71-79
- Spugnini EP et al (2007) Biphasic pulses enhance bleomycin efficacy in a spontaneous canine perianal tumors model. J Exp Clin Cancer Res 26(4):483-487