What is the primary cause of a Bartholin cyst in women of reproductive age?

Primary Cause of Bartholin Cyst

Bartholin cysts develop from obstruction of the Bartholin gland duct opening into the vestibule, leading to mucus accumulation and cyst formation. 1, 2

Pathophysiology

The Bartholin glands are paired, pea-sized structures located bilaterally at the posterior introitus (approximately 4 and 8 o'clock positions) that normally produce mucus for vaginal lubrication 1, 2. When the duct becomes obstructed at its opening into the vestibule, mucus secretions accumulate behind the blockage, resulting in progressive cystic dilation 1, 2.

Key Mechanism

• Duct obstruction is the fundamental cause, preventing normal drainage of glandular secretions 1, 2
• The obstruction leads to mucus build-up within the duct system, causing progressive enlargement 2
• The glands themselves remain functional and continue secreting, which perpetuates cyst expansion 2

Clinical Context in Reproductive-Age Women

Bartholin cysts are most common in women of reproductive age, when the glands are most active 1. The normally impalpable glands become clinically apparent only when:

• A duct cyst develops from obstruction 1
• Secondary infection occurs, forming a gland abscess 1

Important Clinical Distinctions

Cyst vs. Abscess

• Bartholin duct cyst: Results from simple obstruction without infection 1
• Bartholin gland abscess: Occurs when a cyst becomes secondarily infected, commonly with opportunistic organisms (coliforms most frequent) or polymicrobial flora 3

Less Common Causes of Bartholin Gland Enlargement

While obstruction causing cyst formation is the primary mechanism, other rare causes of glandular enlargement include:

• Nodular hyperplasia: Associated with inflammation or chronic duct obstruction, presenting with nodular enlargement and sometimes subcutaneous mucus accumulation 4, 5
• Inflammatory lesions: Can cause glandular swelling 4

Clinical Pitfalls

Do not assume sexually transmitted infections are the cause. Studies show that Neisseria gonorrhoeae and Chlamydia trachomatis are rarely isolated from Bartholin cysts/abscesses 3. The most common organisms when infection occurs are opportunistic bacteria, particularly coliforms 3.

In perimenopausal or postmenopausal women with irregular, nodular Bartholin masses, consider adenocarcinoma in the differential and pursue excisional biopsy rather than standard cyst management 1.