From the Guidelines
Difference between LSIL and HSIL
Low-grade squamous intraepithelial lesions (LSIL) and high-grade squamous intraepithelial lesions (HSIL) are distinct cervical lesions with varying degrees of abnormal cell growth. LSIL is typically characterized by mild dysplasia, equivalent to CIN 1, and is often managed conservatively 1, whereas HSIL is indicative of more severe dysplasia, encompassing CIN 2 and CIN 3, and requires prompt treatment, often with loop electrosurgical excision procedure (LEEP) or cone biopsy 1.
Management Approaches
The management of HSIL may also involve close surveillance with colposcopy and human papillomavirus (HPV) testing, whereas LSIL may be monitored with less frequent Pap smears and HPV testing 1. The approach to managing these lesions is guided by the risk of progression to cervical cancer, with HSIL posing a significantly higher risk than LSIL.
Key Points
- LSIL:
- Characterized by mild dysplasia (CIN 1)
- Often managed conservatively
- May be monitored with less frequent Pap smears and HPV testing
- HSIL:
- Characterized by moderate to severe dysplasia (CIN 2 and CIN 3)
- Requires prompt treatment, often with LEEP or cone biopsy
- Involves close surveillance with colposcopy and HPV testing
These distinctions are crucial for guiding clinical management and ensuring appropriate follow-up and treatment for women with abnormal cervical screening results 1.
From the Research
Definition and Diagnosis
- Low-grade Squamous Intraepithelial Lesion (LSIL) and High-grade Squamous Intraepithelial Lesion (HSIL) are two types of cervical squamous intraepithelial lesions diagnosed using the Bethesda System 2.
- LSIL is characterized by mild dysplasia, while HSIL is characterized by moderate to severe dysplasia 3.
- The diagnosis of LSIL, cannot exclude high-grade squamous intraepithelial lesion (LSIL-H) is used in some institutions to describe cases that fulfill criteria for both LSIL and atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion (ASC-H) 4.
Clinical Significance
- LSIL is generally considered to be a low-risk lesion, while HSIL is considered to be a high-risk lesion for the development of cervical cancer 3.
- The diagnosis of LSIL-H is associated with a higher risk of high-grade dysplasia or cancer compared to LSIL, but a lower risk compared to HSIL or ASC-H 2, 4, 5.
- The management of women with a diagnosis of LSIL-H should be similar to the management of women with a diagnosis of ASC-H, including timely colposcopy and follow-up 4.
Histological Outcomes
- The most common histological outcome for LSIL is cervical intraepithelial neoplasia 1 (CIN 1), while the most common histological outcome for HSIL is CIN 2/3 5.
- LSIL-H is associated with a higher number of CIN 2 or higher lesions on follow-up compared to LSIL, but a lower number compared to HSIL or ASC-H 2, 5.