We collect cells only from the surface of the epithelium when taking a Pap test.
During a biopsy, we remove a small piece of tissue with special forceps. We can thus study under the microscope the entire thickness of the epithelium as well as the area under the epithelium, to diagnose with precision whether it is a precancerous lesion or cancer.
A biopsy is performed to exclude precancerous lesions or cancer. Only a biopsy can provide an accurate diagnosis of the excised tissue pathology.