What are the Histological Changes in Tumorigenesis?

During tumorigenesis, several histological changes can be observed:

1. Hyperplasia: This is the initial stage where there is an increase in the number of normal cells within a tissue, leading to tissue enlargement.
2. Dysplasia: Cells exhibit abnormal growth and morphology, often with increased nuclear-to-cytoplasmic ratio, irregular nuclear shapes, and disrupted tissue architecture.
3. Anaplasia: Cells lose their differentiation and exhibit high degrees of pleomorphism, abnormal mitoses, and increased nuclear atypia.
4. Neoplasia: This refers to the formation of new, abnormal tissue. Neoplastic cells can be benign or malignant, with malignant cells having the potential to invade surrounding tissues and metastasize.