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

Abstract

Funding informationThe authors have no affiliation and no personal relationships with any companies or products mentioned in this article 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. K E Y W O R D S cervical cancer, liquid-based cytology, Nabothian cyst, tumor diathesis 1 | INTRODUCTION Cervical cancer screening in Switzerland is performed on an opportunistic basis, primarily using cytology by conventional smears and/or liquid-based cytology (LBC). The employment of cytology as a screening tool is certainly justified, as Switzerland has one of the lowest mortality rates for cervical cancer worldwide (1,7/100 000; National Institute for Cancer Epidemiology and Registration; http://www.nicer. org/en/statistics-atlas/cancer-mortality, accessed on June 21, 2018). High standards of cytology have to be maintained and a low falsepositive rate is essential, as positive cytology results cause anxiety and possibly unnecessary colposcopy examinations. Different quality control measures are suggested for cervical cytology, one of which is cytohistological correlation of positive and/or discordant cases. 1 Nabothian cysts (also called mucinous retention cysts or epithelial cysts) are frequent at the squamocolumnar junction (SCJ), an anatomical point of the cervix that is the target of brush sampling during cervical screening cytology. Inspissated mucus contained inside these cysts may exhibit a granular character or can be filled with granulocyte fragments, resembling tumor diathesis (TD), a key cytological feature of frankly invasive carcinoma. 2 Moreover, necrotic debris in glands colonized by high-grade squamous intraepithelial lesions (H-SIL), may also mimic TD.We report here, for the first time, an intriguing case that came to our attention during a discussion about potential mimickers of TD-like material in the Papanicolaou test (PAP test) cytology. | CASE HISTORYA 32-year-old woman had been followed for several years due to a history of cervical dysplasia. On the last routine Pap test smear, atypical squamous cells consistent with H-SIL were identified along with TD-like material, thus...

Cytological and Bacteriological Assessment of the Cervix in Cases Having Nabothian Cysts

“…Histological examination of the entire conization specimen showed 3 foci of H-SIL colonizing cervical glands, Figure 1C (square and inset) next to abundant Nabothian cysts. Some of these were filled with inspissated mucus, containing neutrophils and necrotic-like material, features reminiscent of the cytological finding of TD (8) . Cervical nabothian follicles is commonly benign but we should keep in mind the rare adenoma malignum on imaging and histopathology.…”

“…High standards of cytology have to be maintained and a low false-positive rate is essential, as positive cytology results cause anxiety and possibly unnecessary colposcopy examinations. Different quality control measures are suggested for cervical cytology, one of which is cytohistological correlation of positive and/or discordant cases (8) . A 32-year-old woman had been followed for several years due to a history of cervical dysplasia.…”

“…On the last routine Pap test smear, atypical squamous cells consistent with H-SIL were identified along with TD-like material, thus suggesting invasive carcinoma. On cervical biopsies, areas containing typical low-grade squamous intraepithelial lesion (L-SIL) and H-SIL were diagnosed, but no invasive carcinoma (8) . The subsequent conization showed cellular morphological alterations consistent with koilocytosis associated with H-SIL, and H-SIL colonizing cervical glands, next to abundant Nabothian cysts.…”

“…Inspissated mucus contained inside these cysts may exhibit a granular character or can be filled with granulocyte fragments, resembling tumor diathesis, a key cytological feature of frankly invasive carcinoma. Moreover, necrotic debris in glands colonized by high-grade squamous intraepithelial lesions, may also mimic tumor diathesis (8) . The aim of the work was to correlate between cytological or bacteriological findings and presence of Nabothian cysts.…”

Preoperative diagnosis of cervical cystic lesions by magnetic resonance imaging

“…High viscosity and rich protein content cause high intensity, and a liquid component causes hypo-intensity on T1WI. A previous study reported that all 19 cases of Nabothian cysts showed iso-or high-intensity [12] . On the other hand, LEGH cysts are lled with gastric mucin, and Ohya et al reported that 15/19 (78.9%) cases of LEGH showed hypo-or iso-intensity on T1WI [17] .…”