Carcinoma in situ of exocervix

This code represents the presence of abnormal, pre-cancerous cells confined to the surface layer (epithelium) of the exocervix, the outer portion of the cervix visible during a speculum exam. These cells have not invaded deeper tissues but have the potential to become invasive cancer if left untreated. This condition is also known as high-grade squamous intraepithelial lesion (HSIL) of the exocervix.

Use this code when pathology reports confirm carcinoma in situ specifically of the exocervix. This diagnosis is typically made following an abnormal Pap test and subsequent colposcopy with biopsy. Documentation should clearly specify the exocervical location and the in situ nature of the lesion.

• Differentiate from carcinoma in situ of the endocervix (D06.0) or unspecified cervix (D06.9).
• Do not code as malignant neoplasm (C53.-) unless invasion into deeper tissue is confirmed.
• Ensure the pathology report explicitly states "carcinoma in situ" or "HSIL" and specifies the exocervical site.