Proliferative phase endometrium

Proliferative phase endometrium
Diagnosis in short
LM	round spaced pseudostratified glands, mitoses (stroma and glands), normal gland-to-stroma ratio, no glandular dilation
LM DDx	disordered proliferative phase, simple endometrial hyperplasia, complex endometrial hyperplasia, early secretory phase endometrium
Site	endometrium
Prevalence	common - normal finding

Proliferative phase endometrium, abbreviated PPE, is a very common diagnosis in endometrial specimens.

General

• Day 1-13 in the protypical menstrual cycle of 28 days.
  • May be day 5-13 - if the menstruation is not included.
  • "Exodus" pattern is a term used to describe exfoliation of endometrial cells during the proliferative phase.
    • On pap tests this is associated with the classic double contoured balls of endometrial epithelium and stroma.

Note:

• Proliferative phase = follicular phase.
  • Gynecologists prefer the ovarian descriptor, i.e. follicular phase; pathologists go by what they see, i.e. proliferative endometrium.
• When the patient is >40 years, some advocate the use of the term proliferative type endometrium (instead of the term proliferative endometrium).

Gross

• Thickened endometrium.

Microscopic

Features:

• Glands:
  • Straight, tubular, composed of tall pseudostratified columnar cells - key feature.
  • Mitotic figures - key feature. †
• Stroma:
  • Cellular stroma (spindle cells).
  • Mitoses.
    • Usually harder to find than in the glands.

Notes:

• † McCluggage says one shouldn't call PPE without mitoses, as some pseudostratification can be seen in atrophic endometrium.
  • There is no guidance on how hard one should look. VL suggests searching ~ 10 mm^2 with the 20x objective. This represents approximately ~ 10 fields of view with a microscope that has a 22 mm eye piece.
• Significant negatives:
  • No vacuolation.
  • No mucus secretion.
• Inflammation (neutrophils, rare plasma cell) & stromal breakdown common early in the proliferative phase.

DDx:

• Endometrial polyp.
• Disordered proliferative endometrium.
• Endometrial hyperplasia:
  • Simple endometrial hyperplasia.
  • Complex endometrial hyperplasia.
• Secretory phase endometrium, early - >=50% of gland have subnuclear vacuoles and >=50% of cells in the glands have subnuclear vacuoles.

Images:

• Proliferative phase endometrium (utah.edu).
• Proliferative phase endometrium (cytochemistry.net).

Sign out

ENDOMETRIUM, BIOPSY: 
- PROLIFERATIVE PHASE ENDOMETRIUM.

ENDOMETRIUM, BIOPSY: 
- PROLIFERATIVE PHASE ENDOMETRIUM.
- ENDOCERVICAL MUCOSA AND STRIPPED ENDOCERVICAL EPITHELIUM WITHIN NORMAL LIMITS. 

ENDOMETRIUM, BIOPSY:
- PROLIFERATIVE ENDOMETRIUM, FOCALLY WITH A FIBROTIC STROMA.
- BENIGN STRIPPED ENDOCERVICAL EPITHELIUM.
- NEGATIVE FOR HYPERPLASIA AND NEGATIVE FOR MALIGNANCY.

ENDOMETRIUM, ASPIRATION:
- EARLY PROLIFERATIVE PHASE ENDOMETRIUM WITH SOME SHEDDING (APOPTOTIC CELLS,
  INFILTRATING NEUTROPHILS, BALLS OF CONDENSED ENDOMETRIAL STROMA).
- SCANT STRIPPED ENDOCERVICAL EPITHELIUM WITHIN NORMAL LIMITS.
- NEGATIVE FOR HYPERPLASIA.

Not quite normal

ENDOMETRIUM, BIOPSY:
- EARLY SECRETORY PHASE ENDOMETRIUM.
- FOCUS OF CROWDED PROLIFERATIVE GLANDS, SEE COMMENT.

COMMENT:  
There is a small focus of crowded and irregular proliferative glands
without cytologic atypia.  The possibility of a polyp is considered but the vessels and
polyp-type stroma are lacking.  Suggest clincal follow up with a consideration of a repeat
biopsy in 3 to 6 months to rule out a hyperplastic lesion.

Post-menopausal

ENDOMETRIUM, BIOPSY:
- PROLIFERATIVE TYPE ENDOMETRIUM.
-- NEGATIVE FOR HYPERPLASIA.
-- NEGATIVE FOR MALIGNANCY.

Micro

The sections show endometrium with proliferative glands without significant dilation or irregularity of shape. The gland-to-stroma ratio is within normal limits. Mitotic activity is mild. No nuclear atypia is apparent.

See also

• Endometrium.