| Abstrakt: |
Background: The squamous cell carcinoma is a malignant tumor of epidermal cells in which the cells show differentiation to keratinocytes. It is a common neoplasm affecting all domestic animals and other mammalian species. There are several factors that are associated with the development of a squamous cell carcinoma, including prolonged exposure to ultraviolet light, lack of pigment within the epidermis at the sites of tumor development, and lack of hair or a very sparse hair coat at the affected sites. They can appear anywhere on the animal's body predominantly in areas devoid of hair and ears, eyelids, nose and perineal area. Squamous cell carcinoma may occur in young animals, but the incidence increases with age. The cut surface of the tumor appears grainy, whitish or yellowish. These tumors are very infiltrative but rarely metastasize. Microscopically there is the characteristic feature of squamous cell carcinomas and well differentiated with abundant proliferation of stromal. The tumor is common in the horse, cow, cat, and dog, relatively uncommon in the sheep, and rare in the goat and pig. In sheep and goats there are few data in literature. This paper reports a case of squamous cell carcinoma in the frontal region of the head in a Pardo Alpino goat in Bahia. Case: An 6-year-old female Pardo Alpino goat was made euthanasia and sent for necropsy to the Laboratório de Patologia Veterinária of Universidade Federal do Recôncavo da Bahia, Cruz das Almas (UFRB), Bahia, Brazil. According to the veterinarian the goat began to show a neoformation located in the front of the head. This period was performed surgical excision of the mass and cauterization, but the neoplasm recurred twice in succession. Due to the condition it was in, the animal was euthanized. The animal was necropsied and samples collected from the abdominal cavity, thoracic cavity, nervous system and integumentary system. The samples were fixed in 10% formalin, cleaved, processed routinely for histology, embedded in paraffin, cut at five microns thick and stained with hematoxylin and eosin. The necropsy was found mass measuring 5,0 x 3,5 x 3,5 cm in the frontal region of the head. The cut surface of the tumor had been firm and whitish. There were no metastasis in regional lymph nodes or others organs. Histopathological examination revealed a well-differentiated squamous cell carcinoma displaying central pearls of keratin and a dense fibrous stroma. The cytoplasm was abundant and eosinophilic with indistinct boundaries. Were observed 3-5 mitoses greater increase. Discussion: The diagnosis of squamous cell carcinoma of the goat was established by macroscopic and microscopic findings. In this report the neoplasm grew in the caudal region of the frontal sinus, near the spot where had been deshorned. The presence of squamous cell carcinoma located in the front of the head has not been reported in goats. In cattle there squamous cell carcinoma base of horn, diagnosis which could be considered in this case. These results are similar to those described by other authors. Was not found metastasis in regional lymph nodes and parenchymal organs. Most tumors, although invasive, do not show metastatic to regional lymph nodes. There are not papers in the literature of squamous cell carcinoma at this location. [ABSTRACT FROM AUTHOR] |
