Nabothian cyst (retention cyst) is a benign cystic lesion formed by obstruction of mucus-secreting glands due to squamous metaplasia in the cervical transformation zone. Prevalence increases with age and in multiparous women. Usually asymptomatic and discovered incidentally. Size ranges from a few mm to rarely 4-5 cm. May be multiple. On imaging, appears as a simple cystic lesion within cervical stroma — thin wall, homogeneous fluid content, no enhancement. Has no clinical significance and requires no treatment; however, cervical adenoma malignum (minimal deviation adenocarcinoma) should be kept in the differential diagnosis.
Age Range
20-65
Peak Age
40
Gender
Female predominant
Prevalence
Very Common
Nabothian cysts form as a result of a physiological process in the cervical transformation zone. At the squamocolumnar junction (SCJ), columnar epithelium is replaced by squamous epithelium (squamous metaplasia). During this process, openings of some endocervical glands are sealed by newly formed squamous epithelium and gland secretion (mucus) cannot drain — a retention cyst forms. The cyst wall is lined by a single layer of columnar mucus-secreting epithelium and contents are clear or opaque mucus. This mucus content produces simple fluid signal on imaging — hyperintense on T2, hypointense on T1. In cysts with high protein content, T1 signal may increase but no enhancement occurs because the cyst wall is not vascular. Nabothian cysts are a physiological finding with no neoplastic potential.
Well-defined cystic lesion within cervical stroma that is markedly hyperintense on T2, hypointense on T1, with no enhancement is pathognomonic for nabothian cyst. This triad of signal characteristics — T2 bright, T1 dark, no enhancement — defines a simple fluid-containing avascular cyst. Presence of multiple cysts further strengthens the diagnosis as multiple nabothian cysts are physiologically common.
Anechoic, well-defined, round/oval cystic lesion within cervical stroma on transvaginal US. Thin smooth wall, no internal echoes, posterior acoustic enhancement prominent. Size usually 5-15 mm, rarely >30 mm. May be multiple — multiple simple cysts within cervical stroma are quite common and considered a normal variant.
Report Sentence
Anechoic, well-defined cystic lesion measuring ... mm with posterior acoustic enhancement within cervical stroma, consistent with nabothian cyst.
Markedly hyperintense (bright) cystic lesion within cervical stroma on T2-weighted images. Signal intensity is at the same level as free fluid. Well-defined, round/oval morphology. Surrounding cervical stroma is low signal on T2 creating prominent contrast with the cyst. In cysts containing proteinaceous mucus, T2 signal may mildly decrease but remains hyperintense.
Report Sentence
Markedly hyperintense cystic lesion within cervical stroma on T2-weighted images, consistent with nabothian cyst.
Nabothian cyst generally shows hypointense signal on T1-weighted images — simple mucus content. However, in cysts with high protein content, T1 signal may increase appearing isointense or mildly hyperintense. This may be confused with hemorrhagic cyst or other T1 bright lesions but absence of enhancement supports simple retention cyst.
Report Sentence
Cystic lesion with hypointense/variable signal within cervix on T1-weighted images, consistent with mucus-containing retention cyst.
Nabothian cyst shows no enhancement on contrast-enhanced MRI — cyst contents and wall are avascular. No signal change between pre and post-contrast T1 images. This finding confirms simple cystic nature and is critical in distinguishing from solid lesion or adenoma malignum. In adenoma malignum, enhancement is seen in solid components while nabothian cyst has complete absence of enhancement.
Report Sentence
No enhancement in the cervical cystic lesion on contrast-enhanced MRI, consistent with simple retention cyst (nabothian cyst).
Well-defined, hypodense cystic lesion at water density (0-20 HU) within cervix on CT. No enhancement. Cyst becomes more conspicuous as surrounding cervical stroma enhances. CT detects nabothian cysts incidentally — considered a common normal finding particularly on pelvic CT.
Report Sentence
Hypodense cystic lesion at water density within cervix on CT, evaluated as normal anatomical variant consistent with nabothian cyst.
Criteria
<10 mm in size, solitary or multiple, located within cervical stroma. Most common type. Has no clinical significance and even reporting is debatable — most radiologists consider small nabothian cysts as normal variants.
Distinct Features
<10 mm, solitary/multiple, no clinical significance, reporting unnecessary, normal variant
Criteria
Nabothian cyst >4 cm in size — rare. May be confused with cervical carcinoma or adenoma malignum due to large size. Simple cyst signal characteristics are preserved on MRI (T2 hyperintense, T1 hypointense, no enhancement). May be symptomatic (pressure, urinary symptoms) and may require marsupialization or excision.
Distinct Features
>4 cm, rare, may mimic malignancy, MRI simple cyst signal, may be symptomatic, surgery may be needed
Criteria
Multiple cystic structures clustering deep within cervical stroma — may show extension in tunnel or channel patterns. Requires careful differential with adenoma malignum. In nabothian cyst cluster, no enhancement and regular walls are seen — adenoma malignum shows solid enhancing stroma.
Distinct Features
Deep-seated cyst cluster, tunnel pattern, may mimic adenoma malignum, no enhancement, regular walls
Distinguishing Feature
Cervical carcinoma is a solid, intermediate T2 signal, enhancing mass within cervical stroma showing diffusion restriction. Nabothian cyst is a simple cystic, T2 bright lesion without enhancement and without diffusion restriction. Cervical carcinoma may show stromal invasion and parametrial spread while nabothian cyst does not invade surrounding stroma.
Distinguishing Feature
Cervical polyp is a solid polypoid mass in the endocervical canal containing a feeder vessel and showing enhancement. Nabothian cyst is a simple cystic lesion within cervical stroma that is anechoic and avascular. On US, polyp is echogenic and vascular while nabothian cyst is anechoic and avascular.
Distinguishing Feature
Adenoma malignum (minimal deviation adenocarcinoma) shows multiple, variably-sized cystic structures with solid enhancing stromal component in the cervix — 'cosmos' appearance. Nabothian cysts have no solid enhancing component. In adenoma malignum, cysts are irregularly shaped and variably sized while nabothian cysts are round/oval and regular.
Urgency
routineManagement
conservativeBiopsy
Not NeededFollow-up
no-follow-upNabothian cyst is a physiological finding requiring no treatment or follow-up. Typical small cysts meeting all criteria may not be mentioned in reports or can be noted as normal variants. Giant nabothian cysts (>4 cm) may be symptomatic and require marsupialization or excision. Deep-seated multiple cystic structures may be confused with adenoma malignum (minimal deviation adenocarcinoma) so enhancement status should be evaluated with MRI — biopsy is recommended if enhancing solid component is present.
Nabothian cysts are physiological structures with no clinical significance. No treatment is required. Rarely, they may reach large sizes and be confused with a cervical mass. MRI is valuable when differentiation from adenoma malignum (very rare) is needed.