Pathology of Nabothian Cysts
Nabothian cysts are benign mucinous retention cysts that form when cervical mucus accumulates within obstructed cervical crypts, creating non-neoplastic mucinous cystic lesions of the uterine cervix. 1
Mechanism of Formation
- Nabothian cysts develop through blockage of cervical crypts (glands), leading to trapped cervical mucus and subsequent cyst formation. 1
- The obstruction of these crypts prevents normal mucus drainage, causing progressive accumulation and cystic dilatation. 1
- This process represents a retention phenomenon rather than a neoplastic transformation. 1
Histopathological Characteristics
- The cysts are lined by mucin-producing columnar epithelium, similar to normal endocervical glands. 1
- The cyst contents consist of clear to yellowish mucinous fluid, which can accumulate in large volumes (up to 800 ml in reported cases). 2
- These are definitively benign, non-neoplastic lesions with no malignant potential. 1, 3
Clinical Presentation Patterns
- Most nabothian cysts are small (typically <1 cm) and clinically asymptomatic, requiring no intervention. 1
- Large nabothian cysts (>4 cm) are extremely rare but can reach sizes of 8-15 cm. 1, 3, 2
- Large cysts may be multilocular or multicystic in appearance on imaging. 3, 4
Critical Diagnostic Pitfall
- The major clinical challenge is differentiating large nabothian cysts from adenoma malignum (minimal deviation adenocarcinoma), a mucin-producing cervical malignancy. 1, 3, 5
- Ultrasonography and MRI are valuable for diagnosis, showing anechoic or cystic lesions without solid components. 1
- Histopathologic confirmation through biopsy or excision is recommended when cysts are large or have atypical features to definitively exclude malignancy. 3, 4