Amyloid-Producing Odontogenic Tumors of the Facial Skin in Three Cats

Amyloid-producing odontogenic tumors (APOTs) of the facial skin were diagnosed in 3 domestic cats. The neoplasms had the histopathological characteristics of the odontogenic tumor. The neoplastic cells were present in irregular islands, strands, and sheets. The peripheral neoplastic cells of the islands and strands were arranged in a palisading fashion, while the central cells were polyhedral to stellate and randomly arranged. Multiple spherules of homogeneous eosinophilic material were closely apposed to the neoplastic epithelial cells. The spherules stained with Congo red and produced an apple green birefringence under polarization microscopy, indicative of amyloid. Immunohistochemically, amyloid materials of the neoplasms reacted with polyclonal antibodies for ameloblastin, amelogenin, and sheathlin antibodies. Neoplastic epithelial cells also reacted with antiameloblastin, amelogenin, and sheathlin antibodies, with varied intensity. The histopathological and immunohistochemical characteristics of dermal neoplasms of the 3 cats were analogous to those of APOTs reported in the dog and the cat.

Squamous Cell Carcinoma in a Pig

Background: Squamous cell carcinoma (SCC) is a malignant neoplasm of epidermal cells that exhibits keratinocyte differentiation. These neoplasms are common in dogs, cats, horses, and cattle, relatively uncommon in sheep, and rarely affect goats and pigs. There are several factors that are associated with the development of SCC, including prolonged exposure to ultraviolet light, lack of pigment in the epidermis, and sparse coating or lack of fur at the affected sites. The aim of this study was to report the occurrence of squamous cell carcinoma in a domestic pig.Case: A surgically removed nodule from the left ear of a female, light-colored, three-year-old pig, which breed was not defined, was submitted for histopathological analysis. The sample was fixed in 10% formalin, analyzed macroscopically, routinely processed for histology, sectioned at five microns and stained with hematoxylin and eosin. Additionally, anticytokeratin (AE1/AE3) and anti-vimentin immunohistochemical assays were performed. All additional information was provided by the animal’s owner. According to the history obtained, the animal belonged to a herd made up of five females and one boar. For four months, multiple nodules started to grow on the outer surface of the pig’s ear and in many occasions exhibited ulceration and bleeding. One of the nodules was submitted for histopathology examination. Macroscopically it measured 3 cm in diameter, had an irregular and ulcerated surface, and a wide base. Cut surface had a firm consistency and whitish color. Microscopic examination revealed proliferation of neoplastic epithelial cells arranged in islands and trabeculae, with slightly eosinophilic cytoplasm, pleomorphic, round, reniform nucleus, with loose chromatin and 1-3 nucleolus. Mitotic figures were infrequent. In the central area of the islands, there was individual cell keratinization. There was a moderate, fibrovascular supporting stroma with intense inflammatory infiltrate composed of lymphocytes, plasma cells and eosinophils. Anti-cytokeratin (AE1/AE3) immunohistochemical assay (IHC) revealed a strong diffuse positive staining on the cytoplasm of tumoral epithelial cells, and anti-vimentin IHC showed positive staining on the supporting tissue cells (fibroblasts and endothelial cells).Discussion: The diagnosis of squamous cell carcinoma in this pig was based on clinical and pathological findings since it was observed proliferation of neoplastic epithelial cells often forming “keratin pearls” and immunohistochemistry positive for cytokeratin was immunostaining in the cytoplasm of tumor cells. Information on the occurrence of SCC in pigs is scarce in the literature, especially in Brazil. In a survey of neoplasms in farm animals in Southern Rio Grande do Sul with cases from 1978 to 2002, neoplasms in pigs represented 0.6% of the diagnoses when compared to the number of neoplasms in cattle and horses. The low number of cases in this species is due to the fact that a large proportion of the population is slaughtered at a young age and therefore the chances to develop neoplasms are lower. The main SCC growth sites include areas deprived of hair, especially in animals with unpigmented skin. In the pig described here, the neoplasm was located on the outer surface of the ear, which was exposed to ultraviolet rays. Granuloma, papilloma, and basal cell tumor should be considered in the list of differential diagnosis when SCC is suspected. Neoplasms in pigs are scarcely reported.Keywords: neoplasm, carcinoma, pig, immunohistochemical.

Pulmonary adenocarcinoma in cattle

ABSTRACTThe Macroscopic, histological and immunohistochemical aspects of lung acinar adenocarcinoma and the presence of nodules in the abdominal cavity of an adult female bovine are reported. In the necropsy analysis samples were collected from the: lung, heart, spleen, liver, pancreas, kidney, uterus, intestine, brain, and from nodules found in the lung and abdominal cavity, which were routinely processed to be stained by hematoxylin-eosin and for an immunohistochemistry exam with the antibodies: cytokeratin (dilution 1:200 μL) and vimentin (dilution 1:1000 μL). The histopathological examination revealed neoplastic epithelial cells with acini formation. The immunohistochemical examination of the tumor cells showed positive marking for cytokeratin and the absence of marking for vimentin. According to anatomical, morphological, and histopathological findings, as well as the result of the immunohistochemical examination, the tumor was characterized as lung acinar adenocarcinoma.

GASTRIC CARCINOMA WITH OSSEOUS METAPLASIA IN A DOG

This report describes an unprecedented case of a gastric carcinoma with osseous metaplasia in a 8-year-old male standard poodle. An exploratory laparotomy revealed a firm yellowish nodular mass in the pyloric region. The lesion was surgically removed and submitted for current histological examination. Immunohistochemistry was performed employing monoclonal antibodies for pan-cytokeratin, vimentin, smooth muscular a-actin and BMP-2/4. The mass consisted in neoplastic proliferation of epithelial cells, arranged in a tubular or acinar pattern and supported by scirrhous stroma, with mucin production and multiple foci of heterotopic ossification. Neoplastic epithelial cells showed strong positive immunostaining for AE1/AE3 and BMP-2/4, although they were negative for both vimentin and a-actin. Histopathological findings suggested that the bone tissue may be primarily originated from neoplastic epithelial cells which directly circumscribe the osseous metaplasia foci.

In situ complex adenocarcinoma on the femoral part of the hindlimb in an Asian Leaf Turtle (Cyclemys dentata)

A heterotopic in situ complex adenocarcinoma developing on the hindlimb is reported for the first time from an Asian Leaf Turtle (Cyclemys dentata). The tumour mechanically hampered the movement of the animal. The turtle refused to eat and consequently developed a poor condition. Histopathology of the tumour revealed all characteristics of a well-differentiated adenocarcinoma originating from apocrine gland-like tissue: the irregular, tubular structures varying in size were generally lined by two to four layers of cuboidal to columnar neoplastic epithelial cells. Claudin-5, pancytokeratin, cytokeratin, vimentin, α-SMA and Ki-67 immunohistochemical antibodies were employed for characterising the tumour. The diagnosis was a complex adenocarcinoma originating from apocrine gland-like tissue in a turtle.