Table 6.1 Characteristics of benign and malignant neoplasms.

Characteristic Benign Malignant
Histological differentiation Well differentiated - similar to originating tissue Usually poorly differentiated
Invasion of adjacent tissue Non-invasive. Often well circumscribed and capsulated Invade adjacent tissues and cross tissue boundaries
Rate of growth Slow Rapid
Mitotic index Low High
Metastases Never Sometimes