Clear cell adnexal carcinoma
Clear cell adnexal carcinoma (clear cell hidradenocarcinoma, follicular stem cell carcinoma) are a relatively rare malignant neoplasm of canine connective tissue.
Clear cell are characterized by divergent differentiation into cutaneous adnexa, such as apocrine sweat glands and hair follicles. They presumably originate from follicular stem cells, as some tumor are immunohistochemically positive for cytokeratin and vimentin.
Older dogs appear predisposed and this tumor is often located in the skin or subcutis of the head and trunk.
Histological appearance of clear cell adnexal tumors include high cellularity, marked cellular pleomorphism, loose arrangement of neoplastic cells, and a light blue to gray background resulting from streaming of cytoplasm from ruptured cells.
Criteria of malignancy include marked anisocytosis, anisokaryosis, karyomegaly, macronucleoli, and atypical mitotic figures.
Treatment is by wide-margin surgical excision, but recurrence is relatively common.
- Yasuno K et al (2009) Cutaneous clear cell adnexal carcinoma in a dog: special reference to cytokeratin expression. J Vet Med Sci 71(11):1513-1517
- Schulman, FY et al (2005) Canine cutaneous clear cell adnexal carcinoma: histopathology, immunohistochemistry, and biologic behavior of 26 cases. J Vet Diagn Invest 17:403–411
- Piviani M et al (2012) Cytologic features of clear cell adnexal carcinoma in 3 dogs. Vet Clin Pathol 41(3):405-411
- Schulman FY et al (2005) Canine cutaneous clear cell adnexal carcinoma: histopathology, immunohistochemistry, and biologic behavior of 26 cases. J Vet Diagn Invest 17(5):403-411