Women’s Health

Bethesda Classification System

The Bethesda Classification System

The current method of classification of Pap smear abnormalities is known as the Bethesda System. Under this classification, moderate and severe dysplasias are combined into a single classification known as high grade squamous intraepithelial lesions (HSIL). What used to called “carcinoma in situ” is now considered part of the HSIL classification.

Mild dysplasia is also referred to as LSIL (low grade squamous intraepithelial lesion). Researchers believe that most of these lesions are caused by a less aggressive HPV type. The majority of these lesions spontaneously regress.

What is the relationship between Human papillomavirus (HPV) and cervical dysplasia and cancer?

HPV is a very common virus that causes papillomas or warts. There are over 100 different types of HPV that affect the skin surface as well as various mucous membranes. Certain types can cause warts on the hands and feet (plantar warts). Additionally, there are about 30 types of HPV strains that cause venereal warts–also known as condylomata accuminata—as well as pre-cancerous and cancerous lesions of the cervix, vagina and vulva. In addition, other papillomas viruses cause warts in the throat and around the anus.

This is an electron photomicrograph of a type of human papillomavirus (HPV). You should visit www.hpvfaq.com and www.cancer.gov/cancertopics/factsheet/Risk/HPV for additional and helpful information regarding HPV.

HPV is very common. An estimated 5.5 Million cases are diagnosed each year making it responsible for about 1/3 of all STD infections in the US. Several quick facts about HPV

  • It is acquired through skin to skin contact—not through fluids
  • It can remain dormant for a very long time (years) making it possible for the virus to spread from one partner to the next without any warning such as visible lesion.
  • Most people with HPV don’t know they have the virus—it is asymptomatic.
  • At any given time about 20 Million men and women in the US have an active HPV infection.
  • Nearly ¾ of Americans ages 15-49 have been infection with HPV in their lifetimes
  • Some types of HPV (6, 11, 42, 43, 44) cause genital warts
  • Some types of HPV (16, 18 and less commonly 31, 33, 35, 39, 45, 51, 52, ,56, 58, 59, 68 and 69) cause cervical dysplasia.

We know that the majority of cervical cancer and genital warts is caused by certain strains (6, 11, 16 and 18) of the human papillomavirus (HPV). These viruses are responsible for about 70% of all HPV infections in women.

As of 2006 the FDA has even approved the use of Gardasil, a vaccine to prevent some of the more harmful HPV infections. We are happy to discuss this vaccine to determine if it is right for you. Gardasil may prevent infection from HPV types 6, 11, 16 and 18. While it is helpful it is certainly not a guarantee that you will never develop an HPV infection.