General Veterinary Pathology

SIMPLE TUMOURS

Epithelial neoplasms
	Benign tumour: Papilloma of skin  Note the finger-like projection with a core of connective tissue covered by a superficial layer of the squamous epithelium
	Malignant tumour:  Squamous cell carcinoma Note the characteristic cell nests or ‘pearls’ and groups of epithelial cells surrounded by fibrous tissue.
Mesenchymal neoplasms
	Benign tumour: Hard fibroma Made up of well-developed fibrous connective tissue as bundles. Irregular arrangement of the bundles with small fusiform cells characterized by darkly stained nucleus and abundant collagen
	Malignant tumour: Fibrosarcoma Note the bizarre arrangement of numerous cells of varying sizes with hyperchromatic nuclei and mitotic figures.