What is the usual origin of atypical glandular cells found on cervical cytology?

Atypical glandular cells on cervical cytology originate from glandular structures within the reproductive tract, primarily from the endometrial and endocervical glands. These atypical cells can indicate underlying pathologies, such as pre-cancerous changes or cancer itself.

The endometrium is the inner lining of the uterus, and the endocervix is the inner lining of the cervical canal. Both sites produce glandular cells that can shed into the cervical cytology sample. Therefore, atypical glandular cells can arise from either of these tissues, which is why the correct response includes both the glandular epithelium of the endometrium and the glandular epithelium of the endocervix.

Identifying the source of atypical glandular cells is crucial for further diagnostic workup and management, as conditions affecting these glands can lead to significant health concerns, including endometrial hyperplasia or cancer. This dual origin is what makes the option that includes both the endometrium and endocervix the most comprehensive and accurate choice.