Which pre-invasive cervical glandular lesions have a low Ki-67 proliferation index?

• A. Endometriosis
• B. Tubo-endometrioid Metaplasia (TEM)
• C. Microglandular Hyperplasia (MGH)
• D. All of the Above

Answer: (D)

Ki-67 proliferation index reflects how actively cells are dividing; a low score suggests limited proliferative activity typical of benign or metaplastic processes, whereas a higher index points toward neoplastic or high-grade lesions. In the context of pre-invasive cervical glandular lesions, the entities listed are known for minimal proliferative activity, which is captured by a low Ki-67.

Endometriosis in the cervix consists of endometrial glands and stroma located outside the uterus. When present in the cervix, this tissue behaves in a benign, hormone-responsive way, with relatively low cellular turnover, so the Ki-67 index remains low.

Tubo-endometrioid metaplasia is a benign metaplastic change in the endocervical glands where the epithelium takes on tubal or endometrioid features. It is not a neoplasm, and its cells do not show marked proliferation, leading to a low Ki-67.

Microglandular hyperplasia is a benign proliferation of small endocervical glands that can mimic adenocarcinoma histologically, but it lacks the high proliferative activity seen in true neoplasia; thus Ki-67 labeling is low.

Because all three conditions demonstrate low proliferative activity, the best answer is that all of the above have a low Ki-67 proliferation index.