Vulval Swelling: A Diagnostic Dilemma

Abstract

Vulval swellings have always caused dilemmas in diagnosis and more so when they are huge in size. Sebaceous cysts are known to occur as a result of blocked pilo-sebaceous gland and duct or as a result of any injury to the skin. Face, neck, chest, back, scalp, and ears are known sites, however, they also occur over private parts. They are mostly asymptomatic but cause intense pain and discomfort if infected. Symptomatic cysts warrant removal.

What was known?

• Epidermoid cysts are known to occur over the vulva.

• Mostly asymptomatic.

• Occur secondary to trauma like episiotomy.

• Incomplete excision due to scarring or faulty technique.

• Recurrence is known due to incomplete removal.

Introduction

Sebaceous cysts often known as epidermal cysts result from folding of the squamous epithelium beneath the epidermis. Etiology of vulval sebaceous cyst is unknown, however, they are known to occur due to obstruction of the pilo sebaceous ducts and gland or secondary to trauma like episiotomy, perineal tear or female genital mutilation (FGM). They appear as firm, mobile, nodular swellings over the vulva or perineum filled with white or yellow semi-solid caseous material containing sebum and dead skin cells. Mostly asymptomatic and need no therapy but symptomatic infected cysts require complete excision of the cyst wall and its contents as incomplete excision leads to scarring and recurrence. The minimal excision technique for epidermal cyst removal is less invasive than complete surgical excision. Malignant transformation is rare.

Case Report

A 35-year-old female presented to Sri Aurobindo Institute of Medical sciences (SAIMS) outpatient department with a painless swelling over the private parts since 10 years [Figure 1]. The swelling was causing difficulty during walking and intercourse since past few months. There was no history of trauma in recent past or present except for an episiotomy during delivery about 12 years back. At present there was no history of fever, pain, bleeding, or discharge from the swelling. She had three living issues and all delivered vaginally. Her menstrual cycles were regular. General and systemic examination revealed no abnormality. On local examination there was a large 10 × 8 cm soft, nontender, well-defined swelling over the vulva on the right side. The skin over the swelling was free and there was no evidence of any discharge or ulceration over the swelling. There was no inguinal lymphadenopathy as well. Bimanual examination was normal. Routine investigations were within normal limits. Ultrasonography of the swelling was suggestive of Bartholin's or epidermal cyst. Patient was then planned for incision and drainage under anesthesia with proper antibiotic coverage. During surgery an incision was given over the most prominent part and around 100-150 cc of oily, grease-like material suggestive of sebaceous cyst was obtained [Figures 2 and 3]. Digital compression was used to express out the cyst contents and later the cyst wall was extracted using an artery forceps but it came out in pieces. Reexploration was needed after 3-4 days due to incomplete excision of cyst wall leading to infection at operative site.

Figure 1.

Pre-operative image of a huge vulval swelling

Figure 2.

Oily, grease-like material suggestive of sebaceous cyst

Figure 3.

Post-operative image

Discussion

Vulval swellings have often been an enigma for clinicians since time immemorial. Bartholin cyst, skene duct cyst, lipoma, fibroma, leiomyoma, syringoma, acrochordon, hidradenoma papilliferum and epidermoid cyst can be considered in differentials of vulval swelling. Sebaceous glands are known to occur throughout the skin except in the skin overlying palms and soles. The principle function of the sebaceous gland is to secrete sebum, hence any obstruction to the pilo-sebaceous gland and duct or any trauma to the skin during episiotomy[1] or FGM[2,3] results in formation of sebaceous cyst also known as epidermoid cyst, epithelial cyst, and keratin cyst. Epidermoid cyst are mostly firm, fluctuant, mobile, painless slow growing dome shaped swellings with a black punctum over the upper back, face, neck, ears, and private parts of male as well as female. They range in size from few millimeters to 5-6 cm. However, such a large vulvar epidermoid cyst has never been reported so far. They contain soft, yellow, oily and greasy material called sebum that contains lipid and keratin. Epidermoid cysts are mostly asymptomatic unless infection occurs and leads to pain and scarring. A myriad of techniques[4,5] have been described for treatment of epidermal cyst. Minimal excision technique is, however, more acceptable than complete excision[6,7] as it is easy and less time consuming. Excision is preferably postponed till inflammation subsides, which usually takes a week time. Scarring[8,9] due to infection often poses problems during excision. The minimal excision technique[10] involves expression of the oily sebum by vigorous digital compression through a small 2-3 mm incision given over the vulvar cyst. The continuous compression loosens the cyst wall from the surrounding tissues to facilitate removal of the sac. The need to close such a small incision with sutures is negligible and this has an edge over other techniques. Routine incision and drainage leads to recurrence and infection due to incomplete excision of cyst wall like in our case. Care should be taken to avoid spraying[11] of oily contents during surgery by use of gauze or splatter-shield. Complications of the surgery includes incomplete excision of the cyst wall, spraying of cyst contents, hematoma, and recurrence. Malignant transformation[12] is rare; however, any abnormality like a hard ulcerative growth or repeated recurrence of the swelling needs confirmation by histo-pathological correlation.

What is new?

• Very few case reports/short communication are reported on vulval epidermoid cysts

• Huge vulval epidermoid cysts like in our case have never been reported till date

• Minimal excision technique is the most acceptable surgical technique.