High grade squamous intraepithelial lesion

High-grade squamous intraepithelial lesion (HSIL) is a term used in the classification of cervical screening results to describe abnormal changes in the cells on the surface of the cervix. HSIL is considered a pre-cancerous condition, indicating a moderate to severe dysplasia that could potentially lead to cervical cancer if left untreated. This condition is identified through Pap tests (also known as Pap smears) and is further investigated with a procedure called colposcopy.

Etiology

HSIL is primarily caused by persistent infection with high-risk types of Human Papillomavirus (HPV), particularly HPV types 16 and 18. These viruses are capable of altering the DNA of cervical cells, leading to abnormal cell growth. Other risk factors include smoking, immunosuppression, and having multiple sexual partners, which can increase the likelihood of HPV infection.

Pathophysiology

In HSIL, the squamous cells of the cervix undergo abnormal changes, showing both cytological and histological dysplasia. This condition is characterized by the presence of cells with increased nuclear-to-cytoplasmic ratios, hyperchromatic nuclei, and irregular nuclear contours. Histologically, HSIL encompasses both moderate dysplasia (CIN 2) and severe dysplasia (CIN 3), including carcinoma in situ, according to the Cervical Intraepithelial Neoplasia (CIN) classification system.

Diagnosis

The diagnosis of HSIL typically begins with abnormal results from a Pap test, which may indicate the presence of atypical squamous cells of undetermined significance (ASCUS), low-grade squamous intraepithelial lesion (LSIL), or HSIL. A colposcopy is then performed to examine the cervix more closely and to take biopsies for histological examination. The Bethesda System is commonly used for reporting cervical cytological diagnoses, including HSIL.

Treatment

The management of HSIL aims to remove or destroy the abnormal cells to prevent progression to cervical cancer. Treatment options include:

• Loop electrosurgical excision procedure (LEEP)
• Cold knife conization
• Laser therapy
• Cryotherapy

The choice of treatment depends on several factors, including the extent of the lesion, patient age, and desire for future fertility. Follow-up after treatment is crucial to monitor for recurrence.

Prevention

Preventive measures against HSIL and its progression to cervical cancer include:

• Vaccination against HPV, particularly for young adolescents before the onset of sexual activity.
• Regular cervical screening through Pap tests and HPV testing to detect precancerous changes early.
• Practicing safe sex and reducing the number of sexual partners to lower the risk of HPV infection.

Prognosis

With appropriate treatment, the prognosis for women with HSIL is generally good. However, it is important for women who have been treated for HSIL to undergo regular follow-up examinations, as there is a risk of recurrence.

See also

• Cervical cancer
• Human papillomavirus infection
• Pap test
• Colposcopy
• Cervical Intraepithelial Neoplasia