Hyperplasia is the enlargement of an organ due to an increased number of cells. There are two types of hyperplasia: physiological/compensatory and pathological. Physiological hyperplasia occurs as a normal response to hormonal or tissue loss stimuli, such as breast growth during pregnancy or liver regrowth after partial resection. Pathological hyperplasia results from excessive hormonal or growth factor stimulation and can lead to conditions like endometrial hyperplasia. Hyperplasia is caused by increased local growth factors, more growth factor receptors on cells, or activated cell signaling pathways, leading to increased cell proliferation.

1. Enlargement of an organ associated
with increased number of cells

2. HYPERPLASIA
PHYSIOLOGICAL
COMPENSATORY
HORMONAL
PATHOLOGICAL

3. MECHANISM
• For both situation cellular proliferation is
stimulated by growth factors that are produce
by a variety of cell types.

4. PHYSIOLOGIC HYPERPLASIA
1. Hormonal hyperplasia
• increases functional capacity
• Eg: Proliferation of the glandular epithelium
of female breast at puberty and during
pregnancy

5. The growth and multiplication of milk-secreting glandular cells in
the breast as a response to pregnancy, thus preparing for
future breast feeding.

6. • 2. Compensatory Hyperplasia
• increases tissue mass – residual tissue growth
after removal or loss of part of an organ
• Eg: Part of liver resected, mitotic activity in the
remaining cell begin as early as 12 hours later,
eventually restoring the liver to its normal
weight. The stimuli for this setting are
polypeptide growth factor by uninjured
hepatocyte as well as nonparenchymal cells in
liver.

7. PATHOLOGICAL HYPERPLASIA
• Increase tissue mass .
• Causes by excessive hormonal stimulation or
growth factor acting on target cell
• Wound healing
• Viral warts
• Bone marrow
• Lymphoid tissue

8. ENDOMETRIUM HYPERPLASIA

9. PROSTATIC HYPERPLASIA

10. Example
• After a normal menstrual period tehre is a burst of uterine epithelial
proliferation that is normally tightly regulated by stimulation through
pituitary hormones and ovarian estrogen and by inhibition through
progesterone. However, a disturbed balance between estrogen and
progesterone causes endometrial hyperplasia, bleeding. Hyperplasia also
is an important response of connective tissue cells in wound healing, in
which prolifearting fibroblast and blood vessel aid in repair. In this process
growth factor are produced by leokocytes responding to injury and by cells
in wound healing

11. CAUSES
• Hyperplasia generally caused by
 increased local production of growth factor
 increased of growth factor receptor on the responding cell
 activation of particular intracellular signalling pathway
• All these changes lead to production of
transcription factors that turn on many cellular
genes and the net result is cellular proliferation

12. • In hormonal hyperlasia, the hormones act as
growth factor.
• The increase in tissue mass after some types
of cell loss is achieved not only by proliferation
of the remaining cell but also by the
development of new cells from stem cells

13. • The hyperplastic process remain controlled, if
the signal that initiated it abate, the hyperlasia
dissappear.
• It is this reponsiveness to normal regulatory
control mechanism that distinguish pathologic
hyperplasia from cancer.
• In which the growth control mechanism
become dysregulated or ineffective.