عنوان مقاله [English]
نویسنده [English]چکیده [English]
A 5-year old female cow with history of an irregularly shaped and cauliflower-like ulcerated mass was presented to the specialized veterinary hospital, IAU Garmsar Branch. The tumor mass tissue which was located at the left region of the perineum was extended to the right aspect of the vulva and anus and could affected these two regions. The mass was excised from the base by surgeon. The external surface of the mass was completely black, coarse and ulcerative, but on cut surface it appeared grayish-brown with focal purulent areas and fleshy texture and approximately consolidated. The tumor mass tissue formation appeared 3 months earlier to presentation yo clinic as a small neoplastic tissue, and gradually increased in size. The peripheral lymph nodes were normal and there was no evidence of another cutaneous lesion or of metastasis to other organs. Histopathologic examination revealed a well differentiated squamous cell carcinoma in which cells were located in centrifugal circles and surrounding a central acellular pearl of keratin "KeratinPearl" .The tumor cells were large and had an abundant eosinophilic cytoplasm with slightly enlarged hyperchromatic nuclei. They have produced large amounts of keratin, resulting in the formation of extracellular keratin pearls. Tumor cells showed hyperchromatism and mitotic figures in many areas. Based on histopathological characteristics the tumor was diagnosed as squamous cell carcinoma.