Normal histology	Histopathology	Pathological basis of disease	Clinical findings	
•	The endometrium is lined by tall columnar cells with basally located nuclei exhibiting prominent nucleoli.
•	The endometrial lining is supported by a cellular stroma containing numerous simple tubular glands. 
•	Spiral arteries pass to endometrial surface giving off numerous branches which give rise to a capillary plexus around the glands.	Abnormal histology:
•	There is marked hyperplasia of the endometrium, due to proliferation of both the glandular component & the stromal component of the endometrium.
•	The presence of glands of variable shapes & sizes.
•	Majority of the glands are markedly dilated, appearing in cyst-like structures.
•	The lining epithelial cells of the glands may exhibit multilayering.
•	The intervening stroma contains prominent thin-walled blood vessels.
•	Simple hyperplasia: glands are benign as epithelial cells are confined with in basement membrane.
•	Atypical hyperplasia: cellular atypia is present.	•	Response to excessive or uncoordinated ovarian hormone production.	•	Abnormal uterine bleeding.
•	Atypical hyperplasia is associated with a significant frequency of progression to carcinoma.