Hi, Angie! Welcome to Hystersisters!
Endocervical is the area on the inside of your cervix. Your cervix is kind of like a tube, so the cells that grow on the inside of that tube are the endocervical cells. There are different types of cells there including squamous cells which are closer to the lower end of the cervix, and glandular cells which are closer to the top of the cervix near the uterus.
Dysplasia implies that the cells have abnormal characteristics--they are no longer healthy, normal cells. But unlike true cancer, these cells have not begun invading the cervix yet--they are only growing in the "skin" of the cervix.
Dysplasia is subdivided out into different levels. Severe dysplasia means that at least 75% of the cells in the area that was examined are abnormal, but that as many as 25% of them may still be normal (this is a rough description). This is also known as HGSIL (high-grade squamous interepithelial lesion). There is also moderate and mild dysplasia. It's important to have moderate and severe dysplasia treated and monitored. Mild dysplasia must be monitored, but frequently does not require immediate treatment.
Dysplasia is frequently treated with a cone biopsy or LEEP. These procedures remove the abnormal cells, allow for a pathology report to be done to ascertain the severity of the condition, and then in 80-90% of cases is also considered to be the cure for dysplasia.
I hope this helps a little. Please feel free to ask us more questions if you have them.