Benign tumors of the vulva include the ﬁbroma, ﬁbromyoma, lipoma, papilloma, condyloma acuminatum, urethral caruncle, hidradenoma, angioma, myxoma, neuroma, and rarely endometrioid growths.
Condylomata acuminata are a form of papilloma commonly known as venereal warts. These are caused by several serotypes (most frequently serotypes 6 and 11; 90%) of the human papilloma virus. This DNA virus is found in 2% to 4% of all women, and up to 60% of patients have evidence of the virus when polymerase chain reaction techniques are used. The virus is hardy and may resist even drying, making transmission and autoinoculation common. There is some evidence that fomite transmission could rarely occur. The virus is most commonly spread by skin-to-skin (generally sexual) contact and has an incubation period of 3 weeks to 8 months, with an average of 3 months. Roughly 65% of patients acquire the infection after intercourse with an infected partner. The papillomas usually appear as multiple, soft, pointed, warty excrescences about the labia and perineum. When numerous, they may give rise to a conﬂuent, cauliﬂower-like growth. Histologically, they present a central stroma of congested and inﬁltrated connective tissue covered by hypertrophied, stratiﬁed squamous epithelium with deep papillary projections and a thick, superﬁcial, corniﬁed zone.
Fibromas arising from the connective tissue of the vulva are usually small to moderate in size. They tend to become pedunculated as they increase in size and weight. Their consistency depends in part on the degree of edema due to degeneration or deﬁciency of the circulation. They may originate from the region of the round ligament or the deeper pelvic structures and present themselves at the vulva. Occasionally, microscopic section reveals an apparent ﬁbroma to be a ﬁbromyoma. Sarcomatous changes may occur, though rarely.
Lipomas of the vulva are less common than ﬁbromas. They are softer and have a more homogeneous consistency. They may occasionally reach large proportions. The hidradenoma is a benign, relatively rare tumor of sweat gland origin. It appears usually as a small nodule on the labium majus or in the interlabial sulcus. The skin over the surface of the tumor may ulcerate and bleed, giving rise to a grayish or red fungating tumor, sometimes mistaken for carcinoma. Histologically, the hidradenoma or sweat gland adenoma presents an edematous, tubular structure lined by nonciliated columnar cells with clear cytoplasm and dark-staining nuclei. In the smaller acini, cuboidal or rounded cells may be evident. Cystic changes and intracystic papillary proliferations are not infrequent.
Urethral caruncles are pedunculated or sessile, small to pea-sized, bright-red growths projecting from the posterior edge of the urethral meatus. They may be granulomatous, angiomatous, or telangiectatic. They are extremely sensitive and often give rise to urinary frequency and dysuria. Because of the associated vascularity, edema, and inﬂammatory reaction, bleeding occurs readily. Repeated or chronic infections of the urethra or bladder may predispose toward the development of a caruncle. It is important to discriminate a caruncle from patulous or simple eversion of the external urethral meatus, prolapse of the urethral mucosa, and localized carcinoma of the urethra. Urethral prolapse occurs most commonly in elderly women. The entire circumference of the urethral mucosa is seen to protrude through the external meatus, similar to that seen in prolapse of the rectal mucosa through the anus. Congestion and edema are marked. Localized thrombosis and necrosis may occur, accompanied by severe bleeding. A small carcinoma of the urethra may simulate or be superimposed upon a urethral caruncle. Errors in diagnosis may be avoided by biopsy or excision instead of destruction by cauterization.