Colposcopy iodine test negative

Colposcopy is an electronic endoscope that is between the human eye and a high-power microscope. It can be magnified 10-60 times under strong light. By taking advantage of this magnification effect and the function of special test reagents, doctors can clearly observe lesions in the private parts, vagina, and cervix. They can observe the subtler lesions in the vagina and cervix that are invisible to the human eye, and perform precise puncture biopsy at abnormal locations.

Iodine tests are generally used in gynecological examinations. Basically, when doing a colposcopy, after wiping acetic acid on the cervix, iodine solution, that is, spiny seed iodine solution, is applied on the basis of the acetic acid white to observe the color of the cervix. This is called the iodine test.

If the iodine test is positive, it means that the cervix is ​​stained brown-black by the thorny seed iodine solution, indicating that there is no problem with the patient's cervix. If there is no coloring, the iodine test is negative. Further analysis is needed to see if it is an inflammation or other problem.

The unique experimental reagents include saline, 5% glacial acetic acid and 5% spinulosus iodine solution. The normal surface of the vagina and cervix is ​​complete stratified squamous epithelial cells, which contain glycogen. When the cervix and the inner surface of the vagina are wetted with cotton wool containing spiny seed iodine solution, the complete squamous epithelial cells containing glycogen are stained dark brown by iodine. However, columnar epithelial cells, keratinized epithelial cells and abnormal squamous epithelial cells do not have glycogen, so they do not color after applying iodine, and the lesions are usually in the areas that are not colored by iodine.

Inspection method

First, examine the vagina to determine whether an intravaginal microscope can be used, then place a speculum, wipe off the mucus with dilute acetic acid, and use cotton wool to dip in a hematoxylin solution (Mayer's Hematoxylin) to color the cervix for 3-5 minutes until the cervix turns light purple. Wipe off the remaining stain, remove the speculum, and expose the cervix with an angled retractor. The waterproof sleeve is disinfected with medical alcohol and inserted into the vagina after it dries. Place the circle on the casing directly against the part of the cervix to be inspected, shine a strong flashlight directly on it, and make sure that the inspection position is within the circle again. Remove bubbles, move the holder, place the microscope into the casing, connect it to the casing, fix the holder, turn on the flashlight, and you can start the inspection.

Application Standards

1. The patient has no narrow vagina, so the waterproof sleeve can be inserted smoothly.

2. There is no adhesion on the vaginal lips and the cervix can be exposed.

3. There is no cervical bleeding, otherwise what you hear under the microscope is a layer of red blood cells, which hinders the examination of cervical tissue.

Limitations

1. Early cervical cancer is more common in the endocervical canal and is not easily detected using an optical microscope in the vagina.

2. Optical microscopy examination in the vagina is limited to the surface 1-2 layers of epithelial cells and cannot examine shallow infiltrating cancer tumors.

3. When the convex and concave parts on the cervix are far apart, the spherical surface exceeds the focal length of the lens and cervical lacerations cannot be detected.

4. For middle-aged women with vaginal stenosis and patients with cervical adhesions, good examination results cannot be achieved.

5. This method cannot be used to check for late-stage cervical cancer, as there is a lot of rotten tissue and it is easy to bleed.