Endometritis

Endometritis
Diagnosis in short
Chronic endometritis. H&E stain.
LM	acute: abundant neutrophils, clusters >5 (in stroma & glands); chronic: plasma cells (key feature), often eosinophils, lymphoid aggregates
Subtypes	acute, chronic
LM DDx	menstrual endometrium
Site	endometrium
Clinical history	+/-postpartum, +/-recent instrumentation
Prevalence	uncommon
Prognosis	benign

Endometritis is inflammation of the endometrium. It usually subdivided into acute and chronic.

General

• Usually post-delivery or post-instrumentation, e.g. previous biopsy.
• May be spontaneous, e.g. tuberculous endometritis.

Microscopic

Acute endometritis

Features:^{[citation needed]}

• Neutrophils clusters (>5 PMNs) in the:
  • Endometrial stroma.
  • Within uterine glands.

Notes:

• Neutrophils are normal in the context of menses.

DDx:

• Menstrual endometrium - less neutrophils. (???)

Kiviat definition

Kiviat et al. definition - requires both:

1. >=5 PMNs in surface epithelium/400x magnification field of view.
2. >=1 plasma cell in the endometrial stroma/120x magnification field of view.

Notes:

• Above definition is considered "widely accepted".
• Definition suffers from HPFitis and IPFitis.

Image

• Acute endometritis (stonybrook.edu).

Chronic endometritis

Features:

• Plasma cells with in the endometrial stroma - key feature.
  • Usually superficial/close to the luminal aspect.
• Lymphocytic infiltrate - usually marked.
  • May form lymphoid aggregates - low power finding.
• +/-Eosinophils - presence should prompt a search for plasma cells.

Other findings:

• +/-Necrosis.
• Edema - common.
• Hemorrhage.

Notes:

• One plasma cell is not enough to call it.

DDx:

• Menstrual endometrium - endometrial stromal condensation.

Images

• 

  Endometritis - high mag. (WC/Nephron)

• 

  Endometritis - very high mag. (WC/Nephron)

www:

• Chronic endometritis (webpathology.com).
• Chronic endometritis (webpathology.com).
• Tuberculous endometritis (webpathology.com).

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ENDOMETRIUM, BIOPSY:
- CHRONIC ENDOMETRITIS.

Not definite endometritis

ENDOMETRIUM, ASPIRATION:
- PROLIFERATIVE PHASE ENDOMETRIUM WITH A MILD LYMPHOCYTIC INFILTRATE AND VERY RARE
  PLASMA CELLS, SEE COMMENT.
- NEGATIVE FOR HYPERPLASIA.

COMMENT:
The lymphocytic infiltrate and plasma cells raise the possibility of a mild chronic
endometritis; clinical correlation is suggested.

Nonspecific lymphocytic infiltrate

If not more than one plasma cell is apparent after searching.

ENDOMETRIUM, ASPIRATION:
- PROLIFERATIVE PHASE ENDOMETRIUM WITH A MILD LYMPHOCYTIC INFILTRATE.
- SMALL FRAGMENT OF ENDOCERVICAL MUCOSA WITHIN NORMAL LIMITS.
- NEGATIVE FOR HYPERPLASIA.

Micro

The section show proliferative endometrium with a normal gland-to-stroma ratio. Mitotic activity is seen in the glands and stroma. No cytologic atypia is apparent. A mild nonspecific lymphocytic infiltrate is present.

No lymphoid aggregates are apparent. No eosinophils are apparent. No significant number of plasma cells is apparent.

Alternate

The sections show a fragmented nonproliferative endometrium with stromal decidualization and focal glandular dilation. The gland-to-stroma ratio is within normal limits. No cytologic atypia is apparent.

Lymphoid aggregates are present. Focally, rare eosinophils are identified. No significant number of plasma cells is apparent.

See also

• Endometrium.