Variation in the cycle is usually due to differences in the proliferative phase as collapse of the secretory phase into menstruation if fertilisation does not take place is relatively more predictable than the proliferative phase.
In the endometrium, proliferative activity occurs even before the complete cessation of menstruation, i.e. The glands at this earlier stage are relatively straight or, at most, slightly coiled and are found within relatively loose endometrial stroma.
An overview of gynecologic pathology is in the gynecologic pathology article.
ENDOMETRIUM, BIOPSY: - VERY SCANT STRIPPED NON-PROLIFERATIVE COLUMNAR EPITHELIUM, PROBABLY FROM THE LOWER UTERINE SEGMENT. - STRIPPED ENDOCERVICAL EPITHELIUM AND ENODOCERVICAL MUCOSA WITHIN NORMAL LIMITS. COMMENT: A re-biopsy should be considered within the clinical context.
After this, the rate of glandular growth relative to the stroma results in coiling of the glands as the cycle moves towards ovulation.
The nuclei rather than centrally-located are pseudostratified, though they tend to be found in the basal half.
-- Abundant balls of condensed non-proliferative endometrial stroma and blood.
The cut-off is somewhat arbitrary, but there may be a brief overlap of proliferative and secretory phase features, the latter manifest as sub-nuclear vacuolation.
ENDOMETRIUM, BIOPSY: - VERY SCANT STRIPPED EPITHELIUM PROBABLY FROM THE LOWER UTERINE SEGMENT. - SCANT STRIPPED ENDOCERVICAL EPITHELIUM WITHIN NORMAL LIMITS.
- SMALL FRAGMENTS OF DETACHED BENIGN SQUAMOUS EPITHELIUM.
ENDOMETRIUM, ASPIRATION: - CONSISTENT WITH MENSTRUAL ENDOMETRIUM (FRAGMENTED ENDOMETRIUM WITH SIMPLE GLANDS WITH APOPTOTIC CELLS, ABUNDANT NEUTROPHILS, CONDENSED ENDOMETRIAL STROMA (FOCAL) AND BLOOD).
ENDOMETRIUM, ASPIRATION: - ENDOMETRIAL GLANDS WITH APOPTOTIC CELLS, INFILTRATING NEUTROPHILS, AND GLANDULAR PROLIFERATIVE ACTIVITY. - SCANT STRIPPED ENDOCERVICAL EPITHELIUM WITHIN NORMAL LIMITS. COMMENT: The findings are most in keeping with late menstrual endometrium.