Nabothian cysts (also known as a retention cysts of the cervix 11) are non-neoplastic cystic lesion that occurs in relation to the uterine cervix.
They are common and some reports suggest that they may seen in up to 12% of routine pelvic MRI scans 2.
The majority are asymptomatic, although in rare cases they can enlarge and become symptomatic 12.
They are thought to form as a result of the healing process of chronic cervicitis and represent mucinous cysts due to obstruction from overgrowth of squamous epithelium.
Symptomatic Nabothian cysts can also occur as a late complication of subtotal hysterectomy, in which internalisation of the transformation zone and partial obliteration of the canal are postulated as predisposing factors.
Nabothian cysts are usually small spanning a few millimetres in diameter but on occasion, have been reported reach extreme sizes of up to 4 cm.
Tunnel cluster: a special type of Nabothian cyst, is characterised by complex multicystic dilatation of the endocervical glands
Typically seen an anechoic well defined cystic lesions near the endocervical canal. If the cysts are large, the cervical region can appear enlarged 11. Colour Doppler interrogation shows no associated colour flow.
They may be seen as well circumscribed single or multiple cystic lesions within the cervical stroma.
Signal characteristics typically follow that of fluid 2.
- iso to hypointense relative to muscle in typical cases
- very rare cases with mucin may show some high signal
- T2: cysts are hyperintense relative to muscle
- T1 C+ (Gd): there is no associated enhancement
If small may not be detectable on CT. May occasionally be seen a focal low attenuation regions within the cervical region.
Treatment and prognosis
Most Nabothian cysts are clinically insignificant. The majority of cases are not treated because the cysts are entirely benign; however, an excision biopsy is sometimes indicated in large, complex, cystic lesions to rule out rare forms of mucus-producing neoplasia, including adenoma malignum 12.
General imaging differential considerations include:
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- 4. Oguri H, Maeda N, Izumiya C et-al. MRI of endocervical glandular disorders: three cases of a deep nabothian cyst and three cases of a minimal-deviation adenocarcinoma. Magn Reson Imaging. 2004;22 (9): 1333-7. doi:10.1016/j.mri.2004.08.013 - Pubmed citation
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- 6. Oguri H, Maeda N, Izumiya C et-al. MRI of endocervical glandular disorders: three cases of a deep nabothian cyst and three cases of a minimal-deviation adenocarcinoma. Magn Reson Imaging. 2004;22 (9): 1333-7. doi:10.1016/j.mri.2004.08.013 - Pubmed citation
- 7. Bates J. Practical Gynaecological Ultrasound. Cambridge Univ Pr. (2006) ISBN:0521674506. Read it at Google Books - Find it at Amazon
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- 9. Togashi K, Noma S, Ozasa H. CT and MR demonstration of nabothian cysts mimicking a cystic adnexal mass. J Comput Assist Tomogr. 11 (6): 1091-2. - Pubmed citation
- 10. Janus C, Wagner L. Nabothian cysts stimulating an adnexal mass. Clin Imaging. 1989;13 (2): 157-8. Clin Imaging (link) - Pubmed citation
- 11. Fogel SR, Slasky BS. Sonography of Nabothian cysts. AJR Am J Roentgenol. 1982;138 (5): 927-30. AJR Am J Roentgenol (abstract) - Pubmed citation
- 12. Kuligowska E, Deeds L, Lu K. Pelvic pain: overlooked and underdiagnosed gynecologic conditions. Radiographics. 2005;25 (1): 3-20. Radiographics (full text) - doi:10.1148/rg.251045511 - Pubmed citation