Carcinogens, Carcinogenesis and Diagnosis

The tumours (neoplasm) are reported from time immemorial, even several thousand years BC in India. Tumours that are well-differentiated, grow slowly by expansion and do not invade below basement membrane are called as benign neoplasms. Neoplasms, whose cells are anaplastic, metastasise and invade the adjacent tissues and destroy normal tissues. They are also called as cancer ‘like crab’. In this paper, general aspects of tumour aetiology, carcinogenesis, clinico-pathological effects of tumours, diagnosis, staging and grading related to their prognosis and differential features of benign and malignant tumours are described for the benefit of readers just to understand the occurrence of tumours in animals.