Cone Biopsy (Conization): Tissue Removed & Clinical Indications

Tissue Removed

A cone biopsy (conization) excises a cone-shaped specimen from the cervix, encompassing:

• Transformation Zone (TZ): The area where squamous and columnar epithelia meet – the primary site for cervical neoplasia.
• Ectocervix: Squamous epithelium (outer surface).
• Endocervical Canal: Columnar epithelium (glandular tissue) up to the internal os.
• Underlying Stroma: Cervical mucosa and submucosa to a depth of ~1–2 cm.

Indications

• Diagnose/treat CIN 2/3 (high-grade squamous intraepithelial lesion)
• Evaluate adenocarcinoma in situ (AIS)
• Discrepancy between cytology (Pap) and colposcopic biopsy
• Microinvasive carcinoma (stage IA1) – fertility-sparing

Techniques

• Cold knife conization (CKC) – scalpel, OR, general anesthesia
• Loop Electrosurgical Excision Procedure (LEEP/LLETZ) – electrosurgical loop, office-based
• Laser conization – CO₂ laser

Key Point

The specimen must include the entire transformation zone and adequate stromal depth to rule out invasion.