Hyperplasia

Hyperplasia is an increase in the volume of a tissue or organ that results from excessive proliferation of its structural elements (cells).

This is how the body adapts to various stimuli and, unlike neoplastic growth, it is regulated and ceases once the trigger is eliminated. Hyperplasia affects only those tissues whose cells retain the ability to divide.

Etiology and pathophysiology

Depending on the etiology and biological significance, hyperplasia is classified as either physiological or pathological.

• Physiological Hyperplasia. This is a normal adaptive process. Examples include hormonal hyperplasia of the mammary gland epithelium during pregnancy and compensatory liver hyperplasia following partial hepatectomy.
• Pathological Hyperplasia. This form arises from excessive or inappropriate stimulation, most commonly hormonal. Unlike physiological hyperplasia, it may impair organ function and create favorable conditions for the development of malignant neoplasms.

Clinical Significance

Common clinical examples of pathological hyperplasia are benign prostatic hyperplasia (BPH), which causes urinary symptoms in males, and endometrial hyperplasia in females, which may lead to abnormal uterine bleeding.

Although non-cancerous in nature, pathological hyperplasia can represent a premalignant condition. Prolonged excessive cell proliferation increases the likelihood of mutations that may lead to malignant transformation.