CYSTS

Epidermoid cysts

Epidermoid cysts are the most common cysts that occur in the anogenital area. They are lined with stratified squamous epithelium and are filled with the keratin end product of keratinocyte differentiation. Sebum is not present and thus the old term “sebaceous cyst” is a misnomer and its use should be discontinued. In undisturbed cysts, the keratin within the cyst forms a solid white mass but, in inflamed cysts, the keratin is degraded by neutrophils to form a foul-smelling, yellow-white liquid.

Epidermoid cysts form by one of two mechanisms: traumatic inclusion of epithelial fragments or blockage of a pilosebaceous unit. Inclusion-type cysts generally arise during surgical procedures in which fragments of epithelium are unwittingly implanted under the epithelial surface. There, these epithelial fragments round up and the keratinocytes begin making keratin which is released into a central cavity. This mechanism accounts for essentially all the epidermoid cysts encountered within the vagina and most of these occurring in the vulvar vestibule. On the other hand, epidermoid cysts found lateral to Hart’s line (on the labia minora, on the labia majora, and on other hair-bearing portions of the anogenital region) arise from pilosebaceous units. Those with a visible opening (a “blackhead” or tiny pit) on the surface develop due to blockage of the follicular outlet with subsequent production of keratin within the closed space of the follicle. Those without a visible opening are more likely to have developed from a remnant of an anatomically malformed follicle that lacks an opening to the surface.

The size of epidermoid cysts varies from 1 to 2 mm (so-called milia) to several centimeters (Figures 23.1 and 23.2). One or several cysts may be present. Multiple, grouped cysts are particularly common on the labia majora (Figure 23.3). Cysts arising close to the surface appear white or yellow-white due to the visibility of the keratin contents that can be seen through stretched overlying epithelium (Figure 23.4). Deeper lesions are skin-colored. The sharp boundary and firmness of the cyst wall can often be appreciated on palpation. Epidermoid cysts, unless inflamed, are asymptomatic.

Figure 23.1 The diagnosis of epidermal cyst was confirmed by extrusion of the typical odiferous, cheesy keratin contents, but recurrence is expected without removal of the sac wall.

Figure 23.2 Vestigial follicles on the labia minora allow for folliculitis and epidermal cysts in some patients.

(Reproduced from P. J. Lynch and L. Edwards Genital Dermatology (Fig. 10-6), New York: Churchill Livingstone; 1994.)

Figure 23.3 Epidermal cysts sometimes present as multiple lesions; these typical yellowish, skin-colored, and white nodules are primarily on the labia minora.

(Reproduced from P. J. Lynch and L. Edwards Genital Dermatology (Fig. 10-7), New York: Churchill Livingstone; 1994.)

Figure 23.4 Typical firm, well-demarcated, asymptomatic nodules of epidermal cysts can be found anywhere on the vulva, and the range from skin-colored to yellow-white can be appreciated in this patient.

As an epidermoid cyst enlarges, the wall may be thinned to the point that rupture occurs. When this happens, the contents of the cyst spill into the surrounding dermis where they incite a foreign-body inflammatory reaction. The resulting bright red, painful nodules may be mistaken for furuncles (“boils”).

Noninflamed small cysts are best left untreated. Larger or symptomatic cysts can be incised with manual extrusion of the cyst contents. Unfortunately cysts treated in this way frequently recur. However, excision of the entire cyst can subsequently be performed while the recurring cyst is still very small.

Bartholin cysts

Bartholin glands are situated bilaterally, posterior and lateral to the vagina. The ducts from these glands open into the vestibule at approximately 5:00 and 7:00 in relation to the vaginal introitus. These glands secrete a mucus-like material that plays a role in lubrication during sexual activity. Cysts form within the ducts of Bartholin glands, presumably as a result of ductal obstruction. Small cysts (< 1 cm) are extremely common. They are painless and may be palpable but may not be visible. Larger cysts (1–5 cm) may be associated with discomfort and may interfere with penile intromission. A characteristic diagnostic feature is the fact that the labium minus crosses over the midline of the cyst (Figure 23.5).

Figure 23.5 Bartholin gland duct cysts are recognized by the presence of a nodule of variable size within the posterior vestibule, with the labium minus transecting the cyst.

(Reproduced from P. J. Lynch and L. Edwards Genital Dermatology (Fig. 10-9), New York: Churchill Livingstone; 1994.)

Bartholin cysts may become inflamed and painful. The historical presumption was that the inflammation was due to infection, especially that of gonorrhea. Today it seems likely that, in most cases, the thinned wall of an enlarging cyst ruptures and releases cyst contents into the surrounding tissue, thereby causing a foreign-body inflammatory reaction. Rarely, Bartholin cysts develop in postmenopausal women as a result of malignant transformation¹. Immediate treatment is that of incision and drainage.

Asymptomatic cysts should be left untreated. Inflamed cysts can be incised and drained, with a sample of purulent material being sent for bacterial culture. Empirical antibiotic therapy may be carried out until the results of the cultures are known. Incised cysts frequently reform, which may then require more extensive surgery such as marsupialization or incision with insertion of a Word catheter¹.

Cysts of the canal of Nuck (female hydrocele)

In women, a diverticulum of peritoneal membrane follows the round ligament and extends through the inguinal ring and into inguinal canal. This peritoneal membrane forms the canal of Nuck in women and is analogous to the processus vaginalis testis in men. Occasionally the canal of Nuck fails to close completely during postembryonic development, in which case it may fill with serous fluid, forming a cyst (female hydrocele). This type of cyst presents clinically as a skin-colored, asymptomatic mass in the inguinal canal or labium majus (Figure 23.6). No treatment is necessary but surgical removal can be carried out if the patient views the cyst as troublesome.

Figure 23.6 This location in the anterior labium majus is typical of a cyst of the canal of Nuck.

Mesonephric and paramesonephric duct cysts

The mesonephric (wolffian) ducts in women form vestigial tissue during fetal development. The paramesonephric (müllerian) ducts form the vagina and uterus. Later in the development of the vagina, the glandular müllerian epithelium is replaced by stratified squamous epithelium. Occasionally, remnants of these ducts undergo cystic dilation. The cysts may be formed from either mesonephric or paramesonephric tissue and are often termed Gartner’s cysts. They usually occur as small (< 1 cm) asymptomatic lesions in the vagina but occasionally they are much larger. Less often, mesonephric tissue forms similar small, asymptomatic cysts in the vulva. These cysts require no treatment but larger lesions may be excised.

Mucinous cysts

Mucinous cysts occur quite commonly in the vulvar vestibule. They arise, presumably as a result of outlet blockage, from the numerous minor vestibular glands that occur in that location. Their size is variable (2–15 mm), as is the color, which may be translucent, skin-colored, light blue, or yellow (Figures 23.7 and 23.8). These lesions are asymptomatic and require no therapy.

Figure 23.7 This mucinous cyst is yellow, although some are skin-colored or blue.

(Reproduced from P. J. Lynch and L. Edwards Genital Dermatology (Fig. 10-10), New York: Churchill Livingstone; 1994.)

Figure 23.8 The translucent nature of this nodule suggests the correct diagnosis of a mucinous cyst.

(Reproduced from P. J. Lynch and L. Edwards Genital Dermatology (Fig. 10-11), New York: Churchill Livingstone; 1994.)

Pilonidal cysts (pilonidal sinus)

Pilonidal “cysts” appear as persistent, painful, inflammatory papules and nodules. Most occur at the upper end of the gluteal cleft in the sacrococcygeal area but there are a few reports of lesions occurring in the vulva, especially in the periclitoral area. It is believed that these lesions arise either as a result of a ruptured, hair-containing dermoid cyst or as a direct reaction to “ingrown” hairs. A chronic draining sinus may connect the inflammatory focus with the surface of the skin. Therapy is difficult and requires surgical removal of the entire inflamed area along with the draining sinus tract. Inadequate excision is quickly followed by recurrence.

BENIGN NEOPLASMS

Melanocytic nevi (moles)

The word nevus derives from the Latin naevus meaning a mark on the skin. As such, there are many forms of nevi, such as vascular nevi, collagen nevi, and pigmented nevi. For the purposes of this section, the term “nevus” will refer only to pigmented nevi made up of melanocytic “nevus” cells.

Epidemiology and clinical manifestations

Several studies have looked at the prevalence of nevi on the vulva but the diagnosis was made on a clinical basis. Only one study included biopsies to determine the underlying nature of the pigmented lesions². In that study most of the pigmented lesions turned out to be lentigines rather than nevi. Lentigines are discussed in Chapter 22. Nevi occurred in 2.3% of patients. All of these patients were Caucasian; no nevi occurred in the small number of Asian or African American women who were examined. One of the nevi showed some atypical features but the other six were histologically benign.

Nevi may appear as flat macules or raised papules. Typical, normal nevi are brown to black, evenly pigmented, sharply marginated, and 2–10 mm in diameter (Figures 23.9–23.13). Occasionally, nevi that are papular may appear tan or skin-colored because of their sparse melanin production. Nevi may be located on either the mucosal or hair-bearing regions of the vulva. Patients with darkly pigmented skin tend to have darker nevi, but note that dark color alone says nothing about malignant potential. Nevi may be present at birth and, in general, these tend to be larger, darker lesions (Figure 23.14). Acquired nevi begin to develop in childhood and may increase in number during early adult life. After mid-adult life, the number of nevi gradually decreases.

Figure 23.9 This nevus is small, well marginated, and regular, with no concern for melanoma.

Figure 23.10 Nevi are relatively common on the modified mucous membranes of the vulva and should be differentiated from pigmented warts and vulvar intraepithelial neoplasia 3.

(Reproduced from P. J. Lynch and L. Edwards Genital Dermatology (Fig. 12-5), Churchill Livingstone.)

Figure 23.11 A typical soft, small, regular nevus on the mons.

(Reproduced from P. J. Lynch and L. Edwards Genital Dermatology (Fig. 12-6), Churchill Livingstone.)

Figure 23.12 Multiple nevi in this sun-protected area are unusual, and the mildly dysplastic large nevus with slightly fuzzy borders also indicated that this woman should be followed with regular and careful whole-body examinations.

Figure 23.13 Although small, the very irregular pigmentation and borders suggest a small atypical nevus or melanoma, but the biopsy showed a benign nevus.

Figure 23.14 Congenital nevi are generally much larger than acquired lesions; although the light brown color resembles a café-au-lait spot, it is a palpable lesion rather than a flat patch.

Some clinicians believe that the examination of nevi with magnification (such as is carried out with dermoscopy or vulvoscopy) allows for better discrimination of benign versus dysplastic or malignant lesions. This approach is currently unproven and adds cost and inconvenience.

Skin tags and fibroepithelial polyps

Skin tags, also known as acrochordons, are extremely common. Approximately half of all adults have them. They occur more frequently in obese individuals and are somewhat more common in women than in men. Typical locations for skin tags are the axillae, neck, groin, and anogenital area. Small lesions are soft, skin-colored or tan, pedunculated papules (Figure 23.15). Most are about 2 mm in diameter at the base and 4–10 mm tall. Larger nodules are termed “fibroepithelial polyps”; some of these may be several centimeters in size (Figure 23.16). Fibroepithelial polyps have particular predilection for the labia majora, upper inner thighs, and buttocks. The histology is similar in both types, with a normal epidermis enclosing loose connective tissue and dilated capillaries. Fat cells are found in the larger fibroepithelial polyps and account for the very soft feel of these lesions on palpation.

Figure 23.15 A soft, skin-colored, pedunculated papule within skin folds that is typical for a skin tag, or acrochordon.

Figure 23.16 Very large skin tags are called fibroepithelial polyps.

Skin tags are associated with increased risks for insulin and lipid abnormalities and, not surprisingly then, also with diabetes. Perianal skin tags are found more often than would be expected with Crohn’s disease. At one time it was believed that skin tags were an indicator pointing to the presence of intestinal polyps but this is no longer thought to be true.

Skin tags are always benign. Treatment may be indicated if they become irritated or infarcted. Removal can be carried out with scissor excision, with or without local anesthesia, depending on size. Alternatively, they can be destroyed with electrosurgery or cryotherapy. Electrosurgery usually requires local anesthesia and cryotherapy is most easily handled by grasping the lesion with forceps and then freezing the forceps until the lesion frosts over. Patients can remove their own lesions by tying a thread tightly around the base. The tags then undergo necrosis and fall off in 7–10 days.

Seborrheic keratoses

Seborrheic keratoses occur as sharply marginated, square-shouldered, pigmented papules 3–20 mm in diameter. Height from the skin surface ranges from 2 to 10 mm. The surface is usually rough to palpation and scale is often visible (Figures 23.17 and 23.18). Note that both of these attributes may be less apparent when seborrheic keratoses develop in moist areas. Most of the lesions are brown but the color varies from light tan to dark black. Seborrheic keratoses only arise on hair-bearing skin and are most commonly located on the trunk and upper extremities. Their prevalence increases with age, rising from about 10% in the third decade to 90% in the eighth decade. In the anogenital area, seborrheic keratoses may be found on the mons pubis, thighs, buttocks, genitocrural folds, and labia majora. Examination with magnification (dermoscopy or vulvoscopy) may reveal the typical small pits that characterize seborrheic keratoses³.

Figure 23.17 The flat-topped keratotic nature of these brown lesions is classic for seborrheic keratoses.

Figure 23.18 The keratotic nature of the surface of seborrheic keratoses is often less obvious on occluded anogenital skin, but the monomorphous cobblestoned surface is characteristic.

The differential diagnosis for seborrheic keratosis includes warts, VIN, nevi, and melanoma. When the surface of a seborrheic keratosis is scraped with a blade, scale becomes apparent. This is a helpful diagnostic clue since scale is not apparent when nevi and melanomas are scraped. Differentiation from warts and VIN may be difficult. Seborrheic keratoses usually occur as solitary lesions in the anogenital region, whereas warts and VIN are most often multifocal (Figure 23.19). Shave removal for biopsy should be carried out in most instances where there is diagnostic question but if melanoma is a strong consideration, excisional biopsy is preferred. Biopsies from lesions mistakenly considered to be seborrheic keratoses in nongenital areas reveal the presence of melanoma in about 0.5% of specimens⁴.

Figure 23.19 Multiple seborrheic keratoses can occur, but should suggest a diagnosis of pigmented genital warts or vulvar intraepithelial neoplasia 3, which can be indistinguishable.

Seborrheic keratoses probably arise as clonal proliferations of epithelial cells. A significant proportion of the cells demonstrate mutations⁵. Cell markers for proliferation and inhibitors of apoptosis are also regularly present⁶. For some time questions have been asked about what, if any, role human papillomavirus (HPV) infection plays in the etiology of seborrheic keratoses. This controversy currently remains unresolved, though most clinicians believe that lesions of this type demonstrating the presence of HPV DNA are actually misdiagnosed warts.

Clinically typical seborrheic keratoses are benign lesions and no therapy is necessary. Lesions that are inflamed or otherwise troubling to the patient are best treated with cryotherapy⁷.

Hemangiomas

Vascular anomalies are classified as either vascular malformations or vascular tumors. Only the latter are commonly encountered in the anogenital area and these occur almost only in infants. The preferred term, “hemangiomas of infancy,” includes lesions previously described as capillary, cavernous, and strawberry hemangiomas.

Epidemiology and clinical manifestations

Approximately 2% of infants are born with hemangiomas and up to 10% will have developed hemangiomas by the end of the first year of life. They occur more commonly in light-skinned infants and in those born prematurely. Hemangiomas occur four to five times more frequently in girls than in boys. Involvement of the anogenital area occurs more often than would be expected if the distribution of hemangiomas occurred randomly.

Anogenital hemangiomas develop from a red patch but by the time most are recognized they are smooth-surfaced, soft, red nodules varying in diameter from 1 to 10 cm. Less often the lesion appears as a flat, elevated plaque (Figures 23.20 and 23.21). When superficial vessels make up the bulk of the lesion, the color is bright red but when deeper vessels are the ones primarily involved, the color takes on a violaceous or blue hue. Usually only a solitary lesion is present but, in the condition known as hemangiomatosis, multiple lesions are noted. Hemangiomas tend to enlarge slowly over a few months, at which point they stabilize in size. Spontaneous regression, sometimes with scarring, is highly likely by age 5–8 years.

Figure 23.20 Sharply marginated, red hemangioma encompassing the vulva of an infant; the friction of skin folds on this thickened skin is likely to produce nonhealing painful erosions and bleeding.

(Reproduced from P. J. Lynch and L. Edwards Genital Dermatology (Fig. 22-4), Churchill Livingstone.)

Figure 23.21 The bright-red, well-demarcated, superficial component of this hemangioma anterior to the clitoral hood is easily visible; the deeper involvement of the clitoral hood itself is manifested primarily by more diffuse, subtle enlargement of the clitoral hood.

Angiokeratomas

Angiokeratomas occur as age-related, minute varices on the scrotum of men and the vulva of women. In contrast to scrotal lesions, angiokeratomas in women are fewer in number (usually 1–10), larger in size (3–6 mm), and darker (violaceous to blue) in color (Figures 23.22 and 23.23). The lesions appear in adult life. Histologically there is dilation of superficial capillaries overlaid by a slightly thickened epidermis, demonstrating elongation of the rete ridges to partially surround the dilated vessels. In a simplistic manner, these lesions can be thought of as tiny varices. They are asymptomatic and, unless there is frequent bleeding secondary to trauma, no treatment is needed. Symptomatic lesions can be excised or can be destroyed using electrosurgery.

Figure 23.22 Multiple angiokeratomas are common, red to purple, and most often found on the labia majora.

Figure 23.23 Angiokeratomas are sometimes solitary, large, and so dark purple as to appear nearly black; these lesions sometimes mimic nodular melanoma.

Syringomas

Syringomas are benign adnexal neoplasms of sweat gland and sweat duct origin. Historically, it was believed that they were derived from eccrine tissue but more recent data suggest that an apocrine origin is possible. They are very common on the infraorbital region of the face and women are affected more frequently than men. Less often, syringomas are more widely disseminated. Onset is insidious in most instances but an eruptive variety is associated with a fairly rapid appearance of successive crops of new lesions. There appears to be a genetic aspect as many familial cases have been reported.

Syringomas occasionally develop on the vulva, though this is an uncommon finding. Fewer than 50 cases have been reported in the literature and in one older series from a vulvar disease clinic, vulvar syringomas were found in only one of 1100 consecutive patients examined. Almost all vulvar syringomas are found on the labia majora where they appear as clustered papules 5–20 mm in diameter. The papules are sloped-shouldered and smooth-surfaced. Most are skin-colored but white, yellow, and brown hues have been reported (Figures 23.24 and 23.25). Onset is usually in late childhood or early adult life. Pruritus occurs in a considerable proportion of the patients and in some cases it can be severe, leading to superimposed lichen simplex chronicus. Once present, lesions persist indefinitely.

Figure 23.24 Syringomas are generally multiple, and may be skin-colored or white.

Figure 23.25 Often presenting as confluent, skin-colored nodules, syringomas occasionally produce pruritus.

Related posts:

A Systematic Approach to the Dermatoses of Pregnancy The Papular and Pruritic Dermatoses of Pregnancy Atopic Eruption of Pregnancy Vulvar Dermatoses: the Eczematous Diseases Physiologic Skin Changes of Pregnancy of Vulvovaginal Disease

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