Immunohistochemical Expression of Canine Skin and Skin Adnexal Tumors

Introduction
Skin and skin adnexal tumors are very common in dogs (1,3). Skin tumors have a complex histological appearance and sometimes pathological diagnoses is difficult (1,2,3). in this study, canine skin and skin adnexal tumors were investigated with histomorpho- logically and immunochemically by different antibodies.

Material and Methods
The tumour samples were obtained from 56 dogs. all the specimens were after the rou- tin processed stained with haematoxylin-eosin. then, tissue sections intended for the detection immunochemistry with Mnf116, Glial fibrillary acidic protein (Gfap), S-100 protein (S-100), Vimentin (ViM), antineuron Specific Enolase (nSE), α-Smooth Muscle actin (α-SMa), factor fViii (fViii), Ki67, CD18 and CD79. the tumors were classified mor- phologically according to the WHo criteria.

Results
The tumors included 15 squoamous cell carcinoma (SCC), 13 hepatoid gland tumors (HGt), 10 basal cell carcinoma (BCC), 8 sweat gland tumors, 7 sebaseöz gland tumors and 3 trichoepitheliomas. all the tumors with adnexal differentiation showed positive reactivity for cytokeratins Mnf116. nevertheless, all tumors were negative for ViM and α- SMa. nSE immunoreactivity was clearly demonstrated in follicular tumors, whereas hepatoid gland tumors showed a local diffuse positive. immunoreactivity with Gfap was observed locally in sebacous, HGt and sweat gland tumors, while S-100 protein reactivity was found sebaseöz gland tumors, sweat gland tumors and HGt. immunore- activity for fViii was observed in HGt and trichoepitheliomas. SCC, BCC, trichoepithelio- mas, sweat gland tumors and sebaseöz gland tumors were positive with Ki67 and nSE. Sebaseöz gland tumors, sweat gland tumors and HGt were immunoreactive with CD79. and also, sweat gland tumors and HGt were immunoreactive with CD18.

Conclusion
The canine skin tumors can be diagnoses after a conventional histological staining. for the evaluation of canine skin tumors differentiation, it must use different types of anti- bodies, which is especially sensitive only for canine skin tumors.