What is a vulval cyst?
A vulval cyst is an encapsulated lesion that contains fluid or semi-fluid material occurring on the external female genitalia. Vulval cysts can develop from any of the structures normally found in this complex area.
Who gets vulval cysts?
Females of any age can present with a vulval cyst; however, a particular type of cyst may be more common in a specific age group.
What causes vulval cysts?
Vulval cysts can be developmental, genetic, post-traumatic, or spontaneous.
What are the clinical features of vulval cysts?
Vulval cysts are dome-shaped, firm or fluctuant, discrete lesions which may be asymptomatic and noticed incidentally, or present due to pain or dyspareunia which may be cyclic, intermittent, or persistent. The location or distribution of the cysts can be characteristic for a particular type of cyst.
See Vulval cyst images.
Common cutaneous cysts on the vulva
Vulval milia are 1–2 mm, white cysts very commonly seen on examination of the labia of older women. The patient may be aware of the multiple small lumps, but typically they are asymptomatic and an incidental finding.
Epidermoid cysts are commonly found on the cutaneous aspect of the labia majora of middle-aged and elderly women. The cysts may be solitary or multiple, spontaneous or post-surgical, usually presenting as a painless lump up to a centimetre in diameter. Giant epidermoid cyst of the vulva has been described.
Cysts specific to the vulval area
Bartholin and Skene duct cysts
Cysts of the Bartholin gland or Skene duct contain clear mucoid fluid. Bartholin glands are located towards the back and side of the introitus at the 4 o’clock and 8 o’clock positions. Skene glands are adjacent to the distal urethra. Cysts may present as a lump, or as painful swelling if the cyst has become infected and an abscess has formed. Bartholin duct cysts are reported to affect 2% of adult women at some time in their life. Skene duct cysts can also present in neonates. Diagnosis is usually made by the anatomic location of the cyst.
Vestibular mucinous cyst
Mucinous cysts develop from minor vestibular glands found on the inner labia minora along Hart lines. Cysts may be found incidentally, present as a palpable lump noticed by the patient, or cause pain should the cyst become inflamed. Vestibular mucinous cysts typically develop between puberty and the fourth decade.
Cyst of the canal of Nuck
A cyst of the canal of Nuck is a developmental anomaly due to incomplete closure of the round ligament and is the equivalent of a spermatic cord hydrocele in males. It presents as a skin-coloured, asymptomatic swelling located in the inguinal area and labium majorum, resembling an inguinal hernia. It is usually detected by five years of age.
A Gartner, or mesonephric, cyst develops in remnants of an incompletely regressed mesonephric duct. The mesonephric duct forms the male sexual organs, so should regress completely in the female fetus. Persistent mesonephric duct remnants in a female are usually associated with congenital abnormalities of the metanephric urinary system such as an ectopic ureter, unilateral renal agenesis or hypoplasia. A Gartner cyst is a small solitary unilateral cyst on the front vaginal wall towards one side, which may bulge to present as an interlabial mass in late adolescence.
Ciliated cyst of the vulva
At the ninth week of gestation, the paramesonephric duct develops into the fallopian tube. Remnants of this duct can form a ciliated, or paramesonephric, cyst found incidentally on the labium majorum during pregnancy, puberty, or with other hormonal influences. The lesion is usually a single cyst cavity, 1–3 cm in diameter, and drains clear or amber-coloured fluid if ruptured.
Cutaneous cysts that may occur on the vulva
Eruptive vellus hair cysts
Eruptive vellus hair cysts present as multiple small yellow-brown papules usually on the front of the trunk but have been rarely reported on the labia majora.
Steatocystoma is an autosomal dominant skin condition resulting in an abnormal proliferation of the pilosebaceous duct junction. The resultant skin papules drain an oily fluid when punctured. Involvement localised to the vulva has been rarely reported as a late-onset sporadic condition.
Pilonidal disease is usually found at the upper end of the gluteal cleft, but has been reported as a painless papule or nodule on the vulva, particularly in the area around the clitoris, due to an ingrown hair forming a dermoid cyst.
Cutaneous endometriosis can rarely occur on the vulva at the site of previous obstetric or surgical trauma. It presents as nodules, patches, or cysts filled with fresh or clotted blood.
What are the complications of vulval cysts?
- Cyst rupture
- Inflammation and infection
- Pressure effects
- Dyspareunia (painful sexual intercourse)
How is a vulval cyst diagnosed?
Diagnosis of a vulval cyst is usually clinical based on the age at presentation, location, and appearance. Ultrasound examination or histology of a skin biopsy or excision specimen may sometimes be required.
What is the differential diagnosis for a vulval cyst?
- Vascular lesions — cherry angioma, angiokeratoma, haemangioma, varicosities
- Infections — viral wart, herpes simplex virus, bullous impetigo
- Inflammatory conditions — sebaceous adenitis, hidradenitis suppurativa, bullous fixed drug eruption
- Vulval cancer
What is the treatment for a vulval cyst?
The majority of vulval cysts do not require treatment once the diagnosis has been made. Cysts may be drained, marsupialised, extracted, or excised.
What is the outcome for a vulval cyst?
Vulval cysts are generally benign. Some may resolve or rupture spontaneously. Recurrence can follow surgical intervention particularly if the entire cyst wall has not been removed.