What is the diagnostic approach for a patient with ultrasound-confirmed chronic endometritis?

Diagnostic Approach for Ultrasound-Confirmed Chronic Endometritis

The gold standard for diagnosing chronic endometritis is histopathological examination of endometrial tissue with identification of plasma cells, which should be performed even when ultrasound shows clear signs of chronic endometritis. 1, 2, 3

Understanding Chronic Endometritis

• Chronic endometritis (CE) is a persistent, low-intensity inflammation of the endometrial mucosa characterized by plasma cell infiltration into the endometrial stroma 2
• It is often caused by bacterial pathogens including Enterobacteriaceae, Enterococcus, Streptococcus, Staphylococcus, Mycoplasma, and Ureaplasma 4
• CE may be asymptomatic but is found in up to 40% of infertile patients and is associated with repeated implantation failure and recurrent miscarriage 4, 2

Diagnostic Algorithm for Chronic Endometritis

Step 1: Ultrasound Assessment

• Transvaginal ultrasound (TVUS) findings in chronic endometritis may include irregular endometrial thickening, fluid in the endometrial cavity, and heterogeneous endometrial echogenicity 1
• These findings are often non-specific and have limited sensitivity for diagnosing CE 1
• TVUS should be performed with color Doppler to assess for vascularity patterns 5

Step 2: Endometrial Biopsy with Histopathological Examination

• Histopathological examination is the gold standard for diagnosis 2, 3
• The key diagnostic feature is the presence of plasma cells in the endometrial stroma 6, 7
• Consider immunohistochemistry with syndecan-1 staining to improve detection of plasma cells, as this can increase diagnostic accuracy 7

Step 3: Hysteroscopic Evaluation

• Hysteroscopy can detect signs of inflammation including:
  • Focal or diffuse hyperemia
  • Stromal edema
  • Presence of micropolyps
  • Typical "strawberry aspect" of the endometrium 3
• Hysteroscopy has high sensitivity (86-100%) and high negative predictive value (92-100%) but variable specificity 3

Step 4: Microbial Assessment

• Endometrial cultures should be obtained to identify causative pathogens 4, 6
• Consider molecular microbiology methods (PCR) for detection of both culturable and non-culturable pathogens 4
• Molecular methods can identify pathogens such as Chlamydia trachomatis, Enterococcus, Escherichia coli, Gardnerella vaginalis, Klebsiella pneumoniae, Mycoplasma hominis, Neisseria gonorrhoeae, Staphylococcus, and Streptococcus 4

Pitfalls and Caveats in Diagnosis

• Histological identification of plasma cells may be obscured by:

  • Mononuclear cell infiltrate
  • Plasmacytoid stromal cells
  • Abundant stromal mitoses
  • Pronounced predecidual reaction in late secretory endometrium
  • Menstrual features
  • Secondary changes due to exogenous progesterone treatment 7

• Ultrasound findings alone are insufficient for diagnosis due to their non-specific nature 1

• Hysteroscopy tends to overdiagnose CE while histopathology may underdiagnose it, suggesting that combining both techniques may be optimal 3

• Only 20% of cases show consistent results across all three diagnostic methods (histology, hysteroscopy, and microbial culture), highlighting the need for a comprehensive approach 4

Treatment Considerations

• Treatment should be based on identified pathogens when possible 6
• Empiric antimicrobial therapy may be required when specific etiology is unclear 6
• Hormonal manipulation may be considered as part of treatment 6
• Approximately half of CE cases respond to appropriate antibiotic regimens 7