Endometrial Biopsy vs. Pap Smear: Distinct Purposes, Procedures, and Indications
Although both are gynecologic sampling procedures, endometrial biopsy and Pap smear evaluate different anatomic sites and pathologies.
Endometrial Biopsy
- Target: Endometrium (uterine lining).
- Indications: Abnormal uterine bleeding (AUB), postmenopausal bleeding, endometrial hyperplasia/cancer surveillance, infertility workup, hormone therapy monitoring.
- Procedure: Office‑based; Pipelle or Tao brush through cervix into uterine cavity; mild cramping.
- Histology: Assesses architecture, gland‑stroma ratio, atypia.
Pap Smear (Papanicolaou Test)
- Target: Transformation zone of the cervix (ectocervix + endocervix).
- Indications: Cervical cancer screening (ages 21–65 per guidelines), HPV co‑testing, follow‑up of abnormal results.
- Procedure: Speculum exam; spatula/brush collects exfoliated cells; liquid‑based cytology (ThinPrep, SurePath).
- Cytology: Bethesda system (NILM, ASC‑US, LSIL, HSIL, AGC, SCC).
Key Differences at a Glance
| Feature | Endometrial Biopsy | Pap Smear |
|---|---|---|
| Anatomic site | Uterine cavity | Cervix |
| Primary purpose | Evaluate endometrial pathology | Screen for cervical neoplasia |
| Menopause relevance | Indicated for postmenopausal bleeding | Continued per screening guidelines (age‑based) |
| Specimen type | Tissue (histology) | Exfoliated cells (cytology) |