Infectious lesions caused by HPV are internationally referred to as LSIL (Low Grade Squamous Intraepithelial Lesions). They are otherwise referred to as low-grade lesions or condylomatous (warty) lesions.
Low-grade lesions are caused by both low-risk and high-risk HPVs (cancer-causing types).
Premalignant (precancerous) lesions caused by HPV are internationally called HSIL (High-Grade Squamous Intraepithelial Lesions). They are otherwise referred to as high-grade lesions.
Only oncogenic types of HPV (high risk – oncogenic) can cause HSIL.
The terms ‘low-grade’ and ‘high-grade’ were chosen to stress how possible it is for these lesions to grow into cancer.
Based on the above, LSILs are usually followed up, while HSIL lesions must be treated.
Low-grade lesions (LSIL) have a small chance of evolving into cancer (if they have been caused by oncogenic types of HPV). On the contrary, highgrade lesions (HSIL) have a higher chance of evolving into cancer.