Vulvar Cyst

A vulvar cyst is a closed fluid-filled or keratin-filled sac in the vulva. It includes Bartholin duct cysts, Skene duct cysts, epidermal inclusion cysts, mucous cysts of the vestibule, sebaceous cysts and cysts of the canal of Nuck.

• Most are benign, small and asymptomatic.
• Infected cysts form abscesses and need drainage.
• A solid or irregular component, ulceration or age above 40 years needs biopsy.

Smooth, round, mobile swelling, 0.5 to 5 cm, painless unless infected.

• Dyspareunia, tampon difficulty, vulval discomfort or pressure sensation.
• A cyst of the canal of Nuck extends along the inguinal canal and changes with straining.
• Differential diagnosis: Bartholin cyst, epidermal inclusion cyst, Skene cyst, lipoma, hernia, vulval varices, abscess, Gartner duct cyst, vulval carcinoma.
• Complications: infection, abscess, rupture, recurrence, dyspareunia, delivery obstruction when large.

Diagnosis is clinical, by the site and character of the cyst.

• Clinical diagnosis by the site and character of the cyst.
• Ultrasound for deep, solid or inguinal swellings.
• Cyst wall histology after excision or marsupialisation.
• Swab pus for culture and endocervical swab for gonorrhoea and chlamydia.
• Biopsy for any fixed, ulcerated, hard or growing lesion, and for women above 40 years.

Observe small asymptomatic cysts and treat symptomatic or infected cysts by drainage or excision.

• Supportive: reassure that asymptomatic cysts are benign and need no treatment; warm sitz baths 10 to 15 minutes, 3 times daily for discomfort; loose cotton underwear; avoid squeezing.
• Pharmacological: paracetamol 1 g oral 6-hourly (maximum 4 g in 24 hours) for pain; ibuprofen 400 mg oral 8-hourly with food for 3 to 5 days (maximum 1.2 g in 24 hours). Infected cyst: amoxicillin-clavulanate 625 mg oral 8-hourly for 5 to 7 days (child 15 mg/kg of amoxicillin component 8-hourly, maximum 500 mg per dose); penicillin allergy: clindamycin 300 mg oral 8-hourly for 5 to 7 days. For gonorrhoea or chlamydia give ceftriaxone 500 mg IM single dose plus doxycycline 100 mg oral 12-hourly for 7 days.
• Procedures: observation for asymptomatic cysts below 3 cm. Symptomatic Bartholin cysts: Word catheter or marsupialisation. Epidermal inclusion and sebaceous cysts: complete excision of the sac under 1 percent lignocaine (maximum 3 mg/kg, absolute maximum 200 mg plain). Canal of Nuck cyst: surgical excision with high ligation of the processus vaginalis, with repair of any hernia. Infected cyst: incision and drainage first, with excision after 4 to 6 weeks.
• Special groups: in pregnancy avoid ibuprofen from 28 weeks and doxycycline; defer elective excision until after delivery.
• Red flags: rapid growth, hard or fixed mass, ulceration, bleeding, fever with severe pain, age above 40 years.
• Follow-up: review at 2 weeks after any procedure; histology results at 2 weeks; yearly review for observed cysts, sooner if a cyst enlarges.