From the Guidelines
HSIL stands for High-grade Squamous Intraepithelial Lesion, which refers to abnormal, precancerous changes in the squamous cells that line certain body surfaces, most commonly found in the cervix during Pap smear screening, and indicates a higher risk of developing into cervical cancer if left untreated. HSIL represents more severe cellular changes than LSIL (Low-grade Squamous Intraepithelial Lesion) and is typically caused by persistent infection with high-risk types of human papillomavirus (HPV) 1. When HSIL is detected, further evaluation with colposcopy and possibly biopsy is usually recommended to determine appropriate treatment, as outlined in the 2006 consensus guidelines for the management of women with abnormal cervical cancer screening tests 1.
Some key points to consider in the management of HSIL include:
- Immediate loop electrosurgical excision or colposcopy with endocervical assessment is an acceptable method for managing women with HSIL, except in special populations 1
- Observation for up to 24 months using both colposcopy and cytology at 6-month intervals is preferred when CIN 2,3 is not identified histologically, provided the colposcopic examination is satisfactory and endocervical sampling is negative 1
- A diagnostic excisional procedure is recommended if HSIL persists for 24 months without identification of CIN 2,3 1
It's also important to note that HSIL can occur in other areas lined with squamous epithelium, such as the anus, vulva, or oropharynx, where similar evaluation and management approaches may be needed 1. However, the most recent and highest quality study on this topic is the 2006 consensus guidelines for the management of women with abnormal cervical cancer screening tests 1, which provides the most up-to-date recommendations for the management of HSIL.
In terms of specific management strategies, the European guidelines for quality assurance in cervical cancer screening recommend that a woman with a high-grade cytological lesion should be referred for colposcopy, and that colposcopy should only be carried out by adequately trained health professionals 1. However, the 2006 consensus guidelines for the management of women with abnormal cervical cancer screening tests provide more detailed and specific recommendations for the management of HSIL, and are therefore considered the most authoritative source on this topic 1.
Overall, the management of HSIL should prioritize the prevention of morbidity, mortality, and reduction of quality of life, and should be guided by the most recent and highest quality evidence available. In this case, the 2006 consensus guidelines for the management of women with abnormal cervical cancer screening tests provide the most up-to-date and authoritative recommendations for the management of HSIL 1.
From the Research
Definition of HSIL
- High-grade Squamous Intraepithelial Lesion (HSIL) is a category of The Bethesda System (TBS) for reporting cervical cytology that includes moderate dysplasia (CIN II), severe dysplasia (CIN III), and squamous cell carcinoma in situ 2.
- HSIL is a precancerous lesion that can progress to invasive cancer if left untreated 3, 2.
Characteristics of HSIL
- HSIL is characterized by a proliferation of immature basaloid cells with relatively uniform hyperchromatic nuclei 4.
- Some cases of HSIL may exhibit focal but very marked nuclear atypia often associated with multinucleation, known as 'pleomorphic HSIL' 4.
- HSIL can be diagnosed through Pap smears, colposcopy, and biopsy 3, 2, 5.
Diagnosis and Treatment of HSIL
- The diagnosis of HSIL is typically made through a combination of Pap smear, colposcopy, and biopsy 3, 2, 5.
- Treatment of HSIL usually involves removal of the affected tissue through procedures such as large loop excision of the transformation zone (LLETZ) 3.
- A "see and treat" approach, where colposcopy and LLETZ are performed in the same visit, has been shown to be effective and cost-effective in managing HSIL 3.
Prognosis and Risk of HSIL
- HSIL has a high positive predictive value for underlying histopathologic HSIL, indicating a high risk of progression to invasive cancer if left untreated 2, 5.
- The risk of progression from low-grade squamous intraepithelial lesion (LSIL) to HSIL is relatively low, and a diagnosis of HSIL following an LSIL should always be reviewed for potential diagnostic error 6.