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A 4-year-old female beagle with progressive exophthalmos and which had a neoplastic mass with diameter of 1.4 cm in the left lower ocular adnexa. Histologically, the mass was composed of hyperplastic lobules and tubular structures separated by fibrous septum. The well differentiated sebaceous gland forming various sized lobules, and infiltration of mast cells and mononuclear inflammatory cells were observed. Apical decapitation secretion of these tubular structures with basophilic materials in their lumen showed mild sebaceous gland metaplasia. Immunohistochemical studying, cell groups were positive in α-SMA and vimentin. The primary tumor was diagnosed as adenocarcinoma originated from moll gland and meibomian gland of the eyelid, and the infiltrating intraocular neoplasm was diagnosed as a malignant mixed tumor.

A 12.6-year-old, male Shitzu was diagnosed with perianal adenocarcinoma. The presented mass was brown to black, 4×3×3 cm in size, and yellowish on cut section. Microscopic findings revealed that the mass composed of variable sized clusters of hepatoid cells with inconspicuous distinct. The tumor cells were polyhedral and pyknotic and exhibited high mitotic activity. Tumor cells intermingled with basaloid cells and primitive cells invaded the adjacent normal tissues. Basaloid cells exhibited positive immunoreactivity for Epidermal growth factor receptor (EGFR), human epidermal growth factor receptor (HER-2/neu), matrix metallopnateinase 9 (MMP-9), and perianal adenocarcinoma, protein kinase C alpha (PKC α). Generally, tumors of the perianal gland are common and benign 4.5 times more often than carcinoma in the dog, particularly in males. In the present report, we examined histopathological and immunohistochemical characteristics of a rare perianal adenocarcinoma in association with proteins involved tumor metastasis and adenocarcinoma development.

In this study to evaluate the involvement of EGFR, HER-2/neu and ALCAM (CD166) oncogene products in canine mammary neoplastic lesions, sections of archived paraffin-embedded samples of 49 mammary tumors were analyzed immunohistochemically using antibodies against human EGFR and HER-2/neu and ALCAM. These 49 tumors were divided into 2 groups: 22 benign (19 adenoma, 3 benign mixed tumors) and 27 malignant tumors (2 simple adenocarcinomas, 5 complex adenocarcinomas, 3 solid carcinoma, 5 sclerosing carcinoma, 8 malignant mixed tumors and 4 malignant myoepithelioma). As a result of immunostaining, 31.8% (7/22) of the benign tumors and 29.6% (8/27) of the malignant tumors expressed the HER-2/neu oncogene product, EGFR expression was detected in 27.3% (6/22) of benign tumors and in 22.2% (6/27) of the malignant tumors. ALCAM expression was detected in 40.9% (9/22) of benign tumors and in 7.4% (2/27) of the malignant tumors. These results suggest that some of the biological and morphological characteristics of the tumor are associated with canine mammary gland tumors, as also reported for human breast cancer, the possibility of using anti-HER-2/neu antibodies in the treatment of canine mammary tumors.

We describe here a case of malignant mixed osteogenic tumor of the mammary gland with alveolar carcinomatous appreance. A firm, 2 to 2.5cm (in diameter) mass under the 5th nipple, showing the structure of extraosseous osteogenic sarcoma, was removed from the left 5th mammary gland of 12-year-old female dog. When investigated under the microscope, the osteoid material undergoing mineralization was surrounded by numerous scattered osteoblasts and a few osteoclastic cells throughout the osteoid tumorous stroma. The osteoid lesions were continuous with hypercellular myoepithelial cells of a very immature character with several mitotic figures. In addition, there were also carcinomatous tubules and alveoli, with invading cells into peripheral stroma, surrounded by myoepithelial cells in the mammary gland. In these lesions, emanating cords of tumor cells appear to be continuous with the myoepithelial cell layer of a duct. The presence of all these cell types suggests the existence of a common malignant origin, the stem cell being differentiated into epithelial carcinomatous and mesenchymal sarcomatous chondral and osteogenic tissues.

An epulis was occurred on gingiva of 11-year old female dog, Yorkshire terrier. Our case had feature of ossifying epulis but there were a few multi-nucleated giant cells (MGCs). MGCs had osteoclast-like appearance and giant cell epulis usually appears at the site of tooth extraction. Therefore, we suggest that appearance of MGCs in our case may be due to phagocytosis pre-formed osteoid/bone or our case may be mixed epulides of ossifying and giant cell epulis by mixed stimulation of chronic gingivitis and trauma and in flammation by tooth extraction. Thus, MGCs have possibility enough to appear in ossifying epulis, but ossifying epulis accompanying MGCs has not been reported. Therefore, our case may deserves an attention as an unique case and will be helpful to study pathogenesis of giant cell containing lesion of the jaw.

In the study of investigate the expression and effects of adrenomedullin (AM) in the tissue injured by ethanol in our laboratory, there were lymphosarcomas involving mesenteric lymph node and intestine discovered in experimental mice. Lymphosarcoma is probably the second most common spontaneous neoplastic disease, the incidence of which is dependent on the strain of mouse. The diagnosis of lymphosarcoma was based on gross and light microscopic studies. Grossly, the excised intestine and mesentery showed soft-to-firm, cream-colored, displayed protuberance into the lumen. The neoplastic cells had mainly infiltrated into the mucosal and mesenteric lymph node, and have round hyperchromatic nuclei and a small amount of cytoplasm. The origin of these tumor cells was determined by immunohistochemistry positive of CD20, CD3 and Vimentin.