Cervical Intraepithelial Neoplasia Grade 2 (CIN 2) is a diagnosis that follows an abnormal cervical cancer screening test, such as a Pap smear. This finding represents a moderate degree of abnormal cell growth on the surface layer of the cervix. CIN 2 is a pre-cancerous condition, meaning it indicates the presence of cells that have the potential to develop into cancer over time if left untreated. Receiving this diagnosis begins a structured process of evaluation and management designed to prevent progression to malignancy.
Defining CIN 2: What the Grades Mean
The cervical intraepithelial neoplasia (CIN) classification system grades the severity of abnormal cell changes seen in a tissue sample. This system includes CIN 1, CIN 2, and CIN 3, reflecting the extent of the cervical lining, or epithelium, that contains altered cells. CIN 2 is defined as moderate dysplasia, where abnormal cells occupy between one-third and two-thirds of the thickness of the epithelial layer.
CIN 1 is the mildest form, often regressing spontaneously. CIN 3 is the most severe grade, affecting more than two-thirds of the layer and including carcinoma in situ. Because CIN 2 is positioned between these extremes and has significant potential for progression, it is categorized as a high-grade squamous intraepithelial lesion (HSIL) along with CIN 3.
The primary cause of CIN 2 is a persistent infection with a high-risk type of the Human Papillomavirus (HPV), particularly HPV-16. While CIN 2 has malignant potential, it remains a localized abnormality on the surface of the cervix. The abnormal cells have not invaded the underlying stromal tissue, which distinguishes it from invasive cervical cancer. Treating CIN 2 is highly effective in preventing cervical cancer.
The Colposcopy Procedure and Diagnosis
The diagnosis of CIN 2 is confirmed through a colposcopy, which follows an abnormal Pap test. This examination uses a specialized, magnified scope to provide a detailed view of the cervix, vagina, and vulva. The goal is to identify and closely examine the area where abnormal cells were detected during screening.
During the colposcopy, a diluted solution of acetic acid (vinegar) is applied to the cervix. This solution temporarily causes areas of dysplasia to turn white, making them more visible to the clinician. The appearance of the tissue and blood vessels helps determine the severity of the lesion.
To obtain a definitive diagnosis, the clinician performs a biopsy, taking a tiny tissue sample from the most abnormal-appearing areas. A pathologist then examines this tissue under a microscope. The CIN 2 diagnosis is ultimately based on this histological examination, confirming the extent of abnormal cells within the epithelial layer.
Management and Treatment Options for CIN 2
Management involves balancing the risk of progression against potential treatment side effects. For young patients (under 25), observation may be acceptable due to the high rate of spontaneous lesion regression. Approximately 50% of CIN 2 cases can regress without treatment, requiring close surveillance with repeat colposcopy and biopsies to monitor for resolution or progression.
For most other patients, treatment is recommended to prevent advancement to CIN 3 or invasive cancer. The primary goal is to either remove or destroy the entire area containing the abnormal cells. Treatment methods are divided into excisional and ablative procedures.
Excisional Procedures
Excisional procedures physically remove the abnormal tissue and are preferred because they provide a specimen for pathological examination, ensuring no invasive cancer was missed. Common excisional techniques include:
- Loop Electrosurgical Excision Procedure (LEEP): Uses a thin, heated wire loop to remove the affected area.
- Cold knife cone biopsy: Uses a surgical scalpel to remove a cone-shaped piece of tissue, typically reserved for lesions extending high into the cervical canal.
Ablative Procedures
Ablative procedures destroy the abnormal tissue without removing a specimen for analysis. These methods, such as cryotherapy or laser ablation, are generally less invasive. Cryotherapy involves freezing the cells using substances like liquid nitrogen. Ablative methods may be an option for women with smaller, easily visible lesions who wish to minimize the impact on future reproductive health.
Monitoring and Long-Term Outlook
A structured surveillance plan monitors for any recurrence following CIN 2 treatment. The success rate for treatment is high, exceeding 90%. However, long-term follow-up is necessary because treated patients remain at a higher lifetime risk of developing subsequent CIN or cervical cancer.
Post-treatment surveillance is referred to as a “test of cure” and begins six months after the procedure. Follow-up involves both a Pap test and an HPV test. A negative high-risk HPV result strongly indicates that the treatment successfully eradicated the lesion, and subsequent testing continues on a regular schedule based on guidelines.
If CIN 2 was managed with observation, the patient undergoes repeat colposcopy, cytology, and biopsy every six months for up to two years. If the CIN 2 persists or progresses to CIN 3, treatment is recommended. HPV vaccination is a preventive measure that can reduce the risk of future lesions, even after a CIN diagnosis.