Squamous intraepithelial lesion of the uterine cervix
Squamous intraepithelial lesion of the uterine cervix is a precancerous lesion of the uterine cervix.
It is generally referred to as squamous intraepithelial lesion, abbreviated SIL, though this is somewhat ambiguous as the terminology is being applied to other anatomical sites, e.g. vagina.
In the past, it was known as cervical intraepithelial neoplasia, abbreviated CIN. Prior to that, it was known as cervical dysplasia.
This topic is dealt with from a cytology perspective in the gynecologic cytopathology article.
- Precursor lesion of cervical squamous cell carcinoma.
- Usually associated with human papilloma virus.
Divided into grades:
The new and old terminology
|SIL (current terminology)||LSIL||HSIL|
|Recent terminology||CIN I||CIN II, CIN III|
|Very old terminology||mild dysplasia||moderate dysplasia, severe dysplasia|
- Used for squamous lesions -- pathologist typically gets several pieces.
- Used for endocervical lesions, i.e. adenocarcinoma in situ (AIS).
- Pathologist gets a ring or donut-shaped piece of tissue.
- Acetowhite lesion at colposcopy.
Low-grade squamous intraepithelial lesion
High-grade squamous intraepithelial lesion
- Diffuse strong staining involving at least all of the basal aspect of the epithelium = CIN II or CIN III.
- Patchy, weak positive staining = CIN I or squamous metaplasia.
- Several positive cells above basal layer suggests CIN II or CIN III.
- Both p16 and Ki-67 are usually negative in CIN I -- 75% of cases.
- CIN I with p16 staining appears to have a higher risk of progression the p16 negative CIN I.
ECC - cannot grade
UTERINE CERVIX, BIOPSY: - FRAGMENTS OF SQUAMOUS EPITHELIUM SHOWING DYSPLASIA, SEE COMMENT. COMMENT: The fragments of squamous epithelium do not show full epithelial thickness. Thus, while dysplasia is apparent, it is not possible to distinguish low-grade from high-grade in this specimen. That said, there is at least low grade-dysplasia. Follow-up is recommended with re-biopsy if clinically indicated.
UTERINE ENDOCERVIX, CURETTAGE: - FRAGMENTS OF SQUAMOUS EPITHELIUM SHOWING DYSPLASIA, CANNOT GRADE, SEE COMMENT. - BENIGN STRIPPED ENDOCERVICAL EPITHELIUM AND BENIGN SCANT ENDOCERVICAL MUCOSA. COMMENT: The fragments of squamous epithelium do not show the full epithelial thickness; this limits the interpretation. A p16 immunostain strongly marks very scant squamous epithelium, and a Ki-67 immunostain marks increased numbers of squamous cells. A cervical biopsy is suggested.
- Singh, M.; Mockler, D.; Akalin, A.; Burke, S.; Shroyer, A.; Shroyer, KR. (Feb 2012). "Immunocytochemical colocalization of P16(INK4a) and Ki-67 predicts CIN2/3 and AIS/adenocarcinoma.". Cancer Cytopathol 120 (1): 26-34. doi:10.1002/cncy.20188. PMID 22162342.
- Jackson, JA.; Kapur, U.; Erşahin, Ç. (Apr 2012). "Utility of p16, Ki-67, and HPV test in diagnosis of cervical intraepithelial neoplasia and atrophy in women older than 50 years with 3- to 7-year follow-up.". Int J Surg Pathol 20 (2): 146-53. doi:10.1177/1066896911427703. PMID 22104735.
- del Pino, M.; Garcia, S.; Fusté, V.; Alonso, I.; Fusté, P.; Torné, A.; Ordi, J. (Nov 2009). "Value of p16(INK4a) as a marker of progression/regression in cervical intraepithelial neoplasia grade 1.". Am J Obstet Gynecol 201 (5): 488.e1-7. doi:10.1016/j.ajog.2009.05.046. PMID 19683687.