Nabothian cyst content: A potential pitfall for the diagnosis of invasive cancer on Pap test cytology.

Nabothian cysts are common, benign findings of the squamocolumnar junction of the adult cervix. These cysts are filled with mucus and can also contain proteinaceous material, neutrophils, or neutrophil debris. Nabothian cysts can be broken by the spatula during smear taking, may stick to the brush and be smeared onto slides in conventional cytology or dissolved in the preserving solution for liquid-based cytology (LBC) preparations. The granular content of Nabothian cysts may be mistaken for the tumor diathesis (TD) pattern associated with invasive carcinoma. In the case described, the patient presented a high-grade squamous intraepithelial lesion associated with granular material (Nabothian cyst content) that we considered erroneously on LBC to be TD-like material, thus, raising the suspicion of invasive carcinoma. To the best of our knowledge, this is the first report showing that Nabothian cyst content may present a potential pitfall in the diagnosis of invasive carcinoma on LBC.