The medical term for an enlarged clitoris is clitoromegaly, or macroclitoris, which describes an increase in the size of the clitoral structure beyond the normal range. This enlargement is generally measured relative to a defined standard, such as a clitoral index exceeding 35 mm\(^2\) in adults, or a length greater than 6.5 mm in newborns. Clitoromegaly is not a diagnosis itself, but a physical symptom indicating an underlying condition that stimulated the growth of the clitoral erectile tissue. The causes are diverse, but the condition is most often linked to excessive exposure to androgens, or male sex hormones, either prenatally or later in life.
Hormonal Imbalances and Systemic Conditions
The most frequent causes of clitoromegaly are systemic conditions resulting in high levels of circulating androgens. Since the clitoris is composed of erectile tissue that responds to androgen stimulation, an overabundance of these hormones increases its size. This hyperandrogenism can be present from birth or acquired later in life.
Congenital Adrenal Hyperplasia (CAH)
Congenital Adrenal Hyperplasia (CAH) is the most common cause of clitoromegaly in newborns. This genetic disorder involves an enzyme deficiency within the adrenal glands, most frequently a lack of 21-hydroxylase. Because of this deficiency, the adrenal glands cannot produce enough cortisol, which results in a buildup of hormone precursors that are then shunted into the androgen production pathway. This surge in androgens like testosterone during fetal development causes the external genitalia to become masculinized, presenting as clitoromegaly and, sometimes, fusion of the labia.
Androgen-Secreting Tumors
Adrenal or ovarian tumors that actively secrete androgens can cause clitoromegaly to develop in adolescents or adults. These rare tumors produce massive amounts of male hormones, leading to signs of virilization that often progress quickly. Ovarian tumors like Sertoli-Leydig cell tumors or Leydig cell tumors, and certain adrenal tumors, including adrenocortical carcinoma, are high-output sources of androgens. The rapid onset of symptoms like clitoral enlargement, voice deepening, and male-pattern hair growth can be an indication of a tumor, suggesting a need for urgent investigation.
Polycystic Ovary Syndrome (PCOS)
Polycystic Ovary Syndrome (PCOS) is a widespread endocrine disorder involving increased androgen production that can occasionally contribute to clitoromegaly. While the primary features of PCOS are hirsutism, acne, and irregular periods, severe cases with high circulating androgen levels can result in mild clitoral enlargement. Unlike the dramatic or rapid changes seen with tumors or CAH, the clitoromegaly associated with PCOS is usually less pronounced and develops gradually. Severe virilization, including marked clitoromegaly, often suggests a diagnosis other than PCOS, such as a tumor, requiring further evaluation.
Localized and Non-Endocrine Causes
Not all instances of clitoral enlargement are due to systemic hormonal overproduction; some result from localized tissue changes or exposure to exogenous substances. These causes do not involve a body-wide hormonal imbalance.
Exogenous Androgen Use
The most common non-hormonal cause in adults is the use of exogenous androgens, such as anabolic-androgenic steroids or testosterone replacement therapy (TRT). These substances, whether taken orally, injected, or applied topically, directly stimulate the androgen receptors in the clitoral tissue, causing it to grow. This effect is a documented side effect of TRT; the degree of enlargement depends on the dosage, compound type, and duration of exposure. Topical application of steroid creams, or the transfer of testosterone gel from an adult user to a child, can also trigger localized growth.
Rare Genetic Conditions
Certain rare genetic conditions can lead to localized tissue overgrowth or abnormal development. Neurofibromatosis, for example, is a disorder that can cause tumors to form on nerve tissue, and in rare cases, this can manifest as a localized neurofibroma on the clitoris, causing non-hormonal enlargement. Similarly, conditions like congenital generalized lipodystrophy, characterized by a loss of body fat and severe metabolic dysregulation, have been reported in association with clitoromegaly.
Localized Physical Conditions
Localized physical conditions, such as cysts, hemangiomas, or inflammation, can also mimic or cause clitoromegaly. A benign epidermoid cyst, an accumulation of skin cells beneath the surface, can form on or near the clitoris, creating the appearance of enlargement. Hemangiomas, which are benign growths of blood vessels, or severe inflammatory skin conditions like lichen sclerosus, can cause localized swelling and tissue distortion that presents as an enlarged clitoris.
Medical Evaluation and Management
When clitoromegaly is identified, the immediate goal of medical evaluation is to determine the underlying cause, especially ruling out a rapidly progressing or life-threatening condition. The diagnostic process begins with a physical examination, including a precise measurement of the clitoris to confirm its size is outside the normal range.
A detailed patient history checks for rapid symptom progression or exposure to exogenous hormones or medications. Laboratory tests check for hormonal imbalances, focusing on key androgens and their precursors. These blood tests typically measure total testosterone, dehydroepiandrosterone sulfate (DHEA-S), and 17-hydroxyprogesterone (17-OHP). Elevated 17-OHP levels are a strong indicator of congenital adrenal hyperplasia, while very high testosterone levels may suggest an androgen-secreting tumor.
If hormone levels are significantly elevated, imaging studies like an abdominal and pelvic ultrasound or MRI are used to visualize the adrenal glands and ovaries, checking for a tumor that could be the source of excess androgen production. Management of clitoromegaly is directed at treating the underlying cause, whether hormonal or localized.
For hormonal causes, treatment involves medication to suppress androgen production or replace deficient hormones. Congenital Adrenal Hyperplasia is managed with corticosteroids to normalize hormone levels, stopping the adrenal glands from overproducing androgens. Androgen-secreting tumors require surgical removal, and clitoral enlargement often regresses once the source of excess hormones is eliminated. If the enlargement is significant and causes physical discomfort or psychological distress, a surgical procedure called clitoroplasty may be considered to reduce the size while preserving sensation.