Ultrasound Prediction of Colposcopic Visibility of the Transformation Zone: The Potential Role of Nabothian Follicles

Abstract

Ahmed Samy El-Agwany

Cervical cancer screening plays an important role in reducing the incidence and mortality of cervical cancer. Abnormal cervical screening results may require further assessment with colposcopy according to the cytological, HPV, and clinical findings. Colposcopy allows direct visualization of the cervix and assessment of the squamocolumnar junction (SCJ) and transformation zone. A colposcopic examination is considered limited when the SCJ or the upper limit of a relevant lesion cannot be completely visualized. The cervical transformation zone develops as the original columnar epithelium undergoes squamous metaplasia. The transformation zone lies between the original SCJ and the current SCJ and represents the area in which cervical intraepithelial neoplasia most commonly develops. Nabothian follicles are commonly encountered within the transformation zone. They develop when squamous metaplasia obstructs the openings of endocervical glands, resulting in retention of mucus within the glandular crypts and formation of cystic structures. Their presence can therefore provide an anatomical marker of previous or ongoing squamous metaplasia.

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