endometrium secretary phase

Endometrium : Secretory phase


Glands :  They are enlarged and dilated, with convolutions and are lined by columnar epithelium. The lining epithelium contains glycogen rich subnuclear vacuoles in the early secretary phase. The vacuoles will be supranuclear in midsecretary phase. In the late secretary phase, the glands are saw toothed and serrated with luminal secretions

Stroma:  the stromal cells which were spindle shaped in proliferative cells, are now enlarged. they are round to polygonal with vesicular nuclei and abundant eosinophilic cytoplasm. This is called predecidual change as these are the precursors of decidual cells in pregnancy.


The endometrium is obtained for evaluation by a process called dilatation and curettage or by endometrial biopsy. This is done to evaluate infertility or dysmenorrhea.

Dating of endometrium:

Proliferative phase

Glands stroma
Early proliferative (day 4-7 ) Straight short glands, thin epithelium Compact. Few mitosis
Mid proliferative ( day 8-10) Columnar epithelium, curved glands Dense stroma, many mitosis
Late proliferative ( day 11-14) pseudostratification , crowded glands


Moderately dense stroma, mitotically active
Ovulation Presence of subnuclear vacuolations in at least 50 % of the glands Same as above

Secretary phase

Days 16-20: early secretory phase (glandular changes predominate)
days 21-27:mid to late secretory phase (stromal changes predominate

Day 15 (interval phase) Not much change
Days 16, 17 Subnuclear vacuolations ( PIANO KEY Appeareance)
Day 18 Vacuoles become small, nuclei reaches base of the cell.
Day 19 Few vacuoles, intraluminal secretions begin, no pseudostratification
Day 20,21 Maximal secretion Stromal edema appears
Day 22 Secretion still active , but subsiding Maximum stromal edema
Day 23 Glands begins to show regressive changes Spiral arterioles become prominent
Day 24 Regressive changes in the glands Predecidual cells begins to appear around the spiral arterioles
Day 25 Marked regression Predecidual cells begins to appear beneath the surface epithelium
Day 26 Marked regression Sheets of predecidual cells, few granular lymphocytes begin to appear
Day 27 Marked regression More granular lymphocytes, focal necrosis
DAY 28 Glands starts shedding, exhausted glands Necrosis and hemorrhage prominent.