Biopsy: histologic analysis confirms the presence or absence of disease
Biopsy is used to obtain samples from tissue that, through prior testing, has been definitively determined to be abnormal or highly suspicious. Histologic analysis can confirm these findings, better characterize the abnormalities, and help direct appropriate intervention. A biopsy may also be taken as part of treatment for pre-cancerous or cancerous lesions.1
Tissue samples are typically prepared with hematoxylin and eosin (H&E) stain and examined using a microscope to identify abnormal patterns of cell growth.
Interest is growing in the ability to stain for other intracellular proteins that are more specific to cervical oncogenesis and that pathologists can interpret more definitively than H&E staining.
Explore different histologies of cervical tissue
Basaloid cells invade lower third of epithelium
Basaloid cells invade lower third to two-thirds of epithelium
Basaloid cells invade two-thirds up to the full thickness of the epithelium
Since the 1980s, cervical intraepithelial neoplasia (CIN) have been classified into three categories2:
- CIN 1 = mild dysplasia
- CIN 2 = moderate dysplasia
- CIN 3 = both severe dysplasia and carcinoma in situ
The key criterion for differentiating among these categories is the amount of tissue comprised of atypical basaloid cells, which is related to progressive loss in the ability of cells to mature and differentiate into normal epithelial layers.2
In CIN 1, atypical basaloid (basal-like) cells occupy the lower third of the epithelium, in CIN 2 they occupy the lower third to two-thirds, and in CIN 3 they occupy two-thirds to the full epithelium.2
More recently, a two-tiered system has been recommended for histology findings.
- Low-grade squamous intraepithelial lesion (LSIL) (CIN 1)
- High-grade squamous intraepithelial lesion (HSIL) (CIN 2 and CIN 3)
A key rationale for this classification is that it more accurately captures the substantial virologic and molecular difference between LSIL and HSIL, while reflecting clinical evidence that shows the difficulty in reproducibly subdividing HSIL into moderate and severe dysplasia (CIN 2, CIN 3).3