of labia minora. (d) Asymmetry of labia minora with bifid insertion on right side.
The average clitoral width in children was measured at 3.8 mm, and this did not alter with age although the other vulval components increased with age [9]. This is important to exclude clitoral hypertrophy. In an adult study, the clitoral width was reported to increase with parity [17], but this has not been confirmed in larger studies.
The vestibule
The vestibule extends from the clitoral frenulum to the fourchette and laterally from the hymenal ring to a variable position on the inner aspect of each labium minus. The vagina, urethra, ducts of Bartholin’s glands, and the minor vestibular glands all open into the vestibule. The area of the vestibule between the vaginal opening and the posterior union of the labia minora forms a shallow depression termed the vestibular fossa or fossa navicularis. Scars from obstetric tears can be seen on the anterior and posterior vestibule and sometimes pigment.
Figure 2.3 Fordyce spots: yellow papules on inner labium majus.
Figure 2.4 Anatomy of the clitoris.
Hart’s line
In some patients, there may be a very distinct line which represents the transition from the keratinised skin of the labium minus to the vestibular mucosa. This was first described by the Edinburgh gynaecologist David Berry Hart in his textbook of gynaecology in 1882 [18] and is termed ‘Hart’s line’. He wrote ‘a line running separates mucous membrane from skin – starting at the base of the inner aspect of the right labium minus, it passes down beside the base of the outer aspect of the hymen, up along the base of the inner aspect of the left labium minus, in beneath the prepuce of the clitoris and down to where it started from’. This is often very obvious, particularly in young women, and the normal mucosal surface medially is frequently mistaken for inflammation (Figure 2.5).
Bartholin’s glands
Bartholin’s glands are situated deeply in the posterior labia majora. They lie just inferior and lateral to the bulbocavernosus muscle and are normally not palpable. The main duct of each Bartholin’s gland passes deep to the labium minus to open into the vestibule, and their openings are often seen at 5 and 7 o’clock. These can be very prominent in some patients with erythema around the glandular duct opening (Figure 2.6).
Figure 2.5 Hart’s line, which demarcates the junction of the keratinised skin of the labia minora with the non‐keratinised mucosa of the vestibule.
Figure 2.6 Openings of Bartholin’s ducts.
Minor vestibular glands
The minor vestibular glands are small shallow glands usually less than 3 mm into the dermis and open directly to the surface. In postmortem studies, they vary in number from 1 to more than 100 [19].
Vestibular papillomatosis
Vestibular papillae are 1–5 mm thin projections that occur in the vestibule and inner labia minora, and are a normal variant (Figure 2.7). It is suggested that they are the female equivalent of the tiny symmetrical projections found around the coronal sulcus known as penile pearly papules of the penis [20]. Originally, it was thought that the lesions were induced by the human papillomavirus (HPV), but there is now good evidence to the contrary [21, 22]. The normal glycogenation of the cells at the vestibule is often mistaken for koilocytosis, which is another reason for good communication with the pathologist.
Vestibular papillae can be distinguished from viral warts as they are soft and the same colour and texture as the surrounding mucosa. They are symmetrical in distribution and each papilla arises from a solitary base (Figure 2.8), whereas viral warts often coalesce into a single base. Dermoscopy has also been used to distinguish the two entities [23] where the single base of each papilla is again confirmed. The application of 5% acetic acid does not produce acetowhitening in vestibular papillomatosis. They are usually asymptomatic, and no treatment is needed.
Figure 2.7 Vestibular papillae. Multiple filiform projections of the vestibular epithelium.
Figure 2.8 Histology of vestibular papillomatosis. Low power showing papillary projections with normal epithelium each arising from individual base.
Hymen
The hymen is a thin membrane of connective tissue surrounding the inner edge of the vestibule and the opening of the vagina. The appearance is again varied and can be a ring or semi‐circular fold. Once ruptured, an irregular ragged edge is left around the vaginal opening, and these small elevations are termed hymenal remnants (Fig 2.9). Rupture can occur with exercise, tampon use, or sexual intercourse. It is clear that hymenal examination does not predict virginity status accurately or reliably and should never be performed for this purpose [24]. Developmental anomalies of the hymen are discussed in Chapter 1.
Figure 2.9 Hymenal remnants and tags.
The external urethral meatus and urethra
The female urethra is about 4 cm long and runs from the bladder downwards and forwards, embedded in the anterior wall of the vagina behind the symphysis pubis. The length can vary, and in a large study of 927 Caucasian women, the length was increased in the obese but reduced
