Figure 4

Histopathological evaluation of mammary gland tumours in dogs. A: Solid adenocarcinoma; The presence of neoplastic, mitotic and inflammatory cells (H&E, X 200.), B: Cartilage tissue cells due to metaplasia in malignant mixed tumour H&E, X 400. C: Myoepithelial reaction included with spindle shape cells in carcinoma, H&E, X 400. D and E: A cystic tumour of adenocarcinoma showing local invasion of interlobular connective tissue and note the high mitotic index and also different mitotic figures (H&E, (H&E, × 400 and 200). F: Papillary adenocarcinoma proliferating neoplastic epithelial cells in the form of papillary projections and presence of mitotic figures. H&E, 200×, G and H: Beinign mixed mammay tumour. Tumour tissue showing epithelial and myoepithelial components, 400×, I: The presence of neoplastics emboli within the dermal lympathic vessels, which was occasionally observed with some of the most aggressive adenocarcinoma, leads to blockage of the superficial dermal lymphatic drainage (H&E, X 200), J: Cholesterol cleft in malignant mixed tumour, (H&E, X 400). K: Cells exhibit variable numbers of mitoses are found; or, the second population of cells may have oval to fusiform vesicular nuclei with an extensive amount of eosinophilic cytoplasm and distinct cells margins (H&E, X 400) L: Haemorrhage foci and the central necrotic areas are interpreted as an indication that the neoplastic cells are growing faster and that there is therefore a higher risk of progression to invasive carcinoma (H&E, X 400).