Is an external cyst on the cervical os called a Nabothian cyst?

Nabothian Cysts on the Cervical Os

Yes, external cysts on the cervical os are called Nabothian cysts (also termed Nabothian follicles), which are benign mucinous retention cysts formed when cervical mucous glands become obstructed. 1, 2

Definition and Pathophysiology

• Nabothian cysts are non-neoplastic mucinous retention cysts that develop when cervical crypts or mucous glands become blocked, leading to accumulation of cervical mucus inside the obstructed glands 2
• These cysts commonly occur in women of reproductive age and are typically associated with childbirth, minor trauma, or chronic cervicitis 3, 4
• They represent a benign gynecological condition with no malignant potential in their typical presentation 1

Clinical Characteristics

Size and Presentation

• Most Nabothian cysts are small (2-10 mm), asymptomatic, and require no intervention 4
• Giant Nabothian cysts (>4 cm) are extremely rare but can occur, with reported sizes up to 9.5 cm 1, 3
• Small cysts are usually incidental findings during routine examination 4

Location

• These cysts arise from the cervical mucosa and can be located on the external cervical os (ectocervix) or within the endocervical canal 1, 4
• Multiple cysts can coexist, creating a multilocular appearance 1, 3

Diagnostic Considerations

Imaging Approach

• Transvaginal ultrasonography is the first-line imaging modality, demonstrating anechoic or hypoechoic cystic lesions with no solid components 2, 4
• MRI provides superior soft tissue characterization when differentiation from malignancy is needed 2
• On imaging, Nabothian cysts appear as well-circumscribed cystic lesions without internal vascularity 1

Critical Differential Diagnosis

• Large or complex Nabothian cysts can mimic adenoma malignum (minimal deviation adenocarcinoma), making histopathological confirmation essential 1, 2, 5
• The key distinguishing feature is that Nabothian cysts are benign with no solid components or malignant features on imaging 2
• Biopsy or aspiration with cytological analysis is recommended when malignancy cannot be excluded based on imaging alone 1, 3

Management

Small, Asymptomatic Cysts

• No treatment or intervention is required for typical small Nabothian cysts 2
• These can be observed without concern 4

Large or Symptomatic Cysts

• Surgical excision (laparoscopic or open) is the definitive treatment for large cysts causing symptoms or diagnostic uncertainty 2
• Simple aspiration can be performed for acute symptom relief (such as obstructing labor passage), though cysts may recur 5, 4
• Complete excision allows for histopathological confirmation and prevents recurrence 2

Common Pitfalls to Avoid

• Do not assume all large cervical cystic masses are benign without proper imaging and, when indicated, histopathological evaluation to exclude adenoma malignum 1, 2
• Avoid performing unnecessary hysterectomy for large Nabothian cysts when minimally invasive excision is sufficient 2
• Do not overlook the possibility that giant cysts may cause mechanical complications such as dyspareunia, pelvic pain, or obstruction during labor 3, 5
• In the context of infertility evaluation, consider that large cervical cysts may obstruct the cervical canal, though their direct role in infertility remains controversial 4