Pathological Hyperplasia: Endometrial and Prostatic

Pathological Hyperplasia

• Examples of pathological hyperplasia include endometrial hyperplasia due to hormonal imbalance, benign nodular prostatic hyperplasia in old age men due to androgen stimulation, and skin warts (hyperplastic epithelium) in response to papillomavirus infection.

Hypertrophy

• Hypertrophy is an increase in cell size of cells, leading to an increase in the size of the affected organ.
• It occurs due to the synthesis and assembly of additional intracellular structural components.
• Permanent cells/non-dividing cells undergo hypertrophy only, while dividing cells (stable cells/quiescent cells) undergo both hypertrophy and hyperplasia.

Types of Hypertrophy

• Physiological hypertrophy: occurs in response to increased functional demand.
• Pathological hypertrophy: occurs in response to increased workload or disease state in cells with limited capacity for division.

Types of Hyperplasia

• Physiological hyperplasia: occurs due to hormonal stimulation or growth factors when there is a need to increase functional capacity of hormone-sensitive organs.
• Compensatory hyperplasia: occurs after damage or resection.
• Pathological hyperplasia: occurs due to excessive hormonal stimulation or excessive effects of growth factors on target cells.

Examples of Physiological Hyperplasia

• Hyperplasia of female breast at puberty and during pregnancy.
• Proliferative activity of normal endometrium after a normal menstrual cycle.
• Regeneration of liver following partial hepatectomy (compensatory hyperplasia).

Metaplasia

• Osseous metaplasia: occurs in arterial wall in old age, in soft tissues in myositis ossificans, in cartilage of larynx and bronchi in elderly people, in scar of chronic inflammation of prolonged duration, and in the fibrous stroma of tumour (leiomyoma).
• Cartilaginous metaplasia: occurs in healing of fractures, in area with undue mobility.
• Other types of metaplasia include apocrine metaplasia, tubal metaplasia, clear cell metaplasia, mucinous metaplasia, and fat metaplasia.

Hyperplasia and Metaplasia as Precursors to Neoplasia

• Hyperplasia and metaplasia can increase the risk of acquiring genetic aberrations, leading to uncontrolled proliferation and cancer.
• Pathological hyperplasia and metaplasia can constitute a fertile soil for cancer development.
• Examples of progression from hyperplasia/metaplasia to carcinoma include endometrial hyperplasia to endometrial carcinoma, metaplasia from squamous to columnar epithelium in Barrett's oesophagus to adenocarcinoma of oesophagus, and squamous cell carcinoma arising from metaplastic squamous epithelium of the bronchial mucosa in a heavy smoker.

This quiz covers examples of pathological hyperplasia, including endometrial hyperplasia caused by hormonal imbalance and benign nodular prostatic hyperplasia in old age men. Understand the differences between normal and hyperplastic tissues.