Causes of Enlarged Clitoris (Clitoromegaly)
Clitoromegaly is primarily caused by androgen excess from conditions including congenital adrenal hyperplasia (CAH), virilizing tumors (ovarian or adrenal), polycystic ovarian syndrome (PCOS), hyperthecosis, and exogenous androgen exposure, though rare non-hormonal causes such as neurofibromatosis, vascular malformations, and cysts must also be considered. 1
Hormonal Causes (Most Common)
Severe Hyperandrogenemia with Virilization
The most clinically significant causes involve severe androgen excess and include 1:
- Adrenal or ovarian tumors - Suspect when clitoromegaly develops rapidly with other virilization signs (deepening voice, male pattern baldness, breast atrophy, androgenic muscle development)
- Congenital adrenal hyperplasia (CAH) - Particularly 21-hydroxylase deficiency, presents with genital ambiguity at birth or progressive virilization 2
- Ovarian hyperthecosis - Severe hyperandrogenemia with pronounced oligomenorrhea or amenorrhea
- Exogenous androgens - Self-injection of long-acting synthetic androgens, danazol, or anabolic steroids 3, 4
Moderate Hyperandrogenemia
- Polycystic ovarian syndrome (PCOS) - Most common endocrinopathy causing hyperandrogenism, though clitoromegaly is less pronounced 1, 5
- Non-polycystic ovarian hypertestosteronism 3
Clinical pitfall: Rapid onset and progression of clitoromegaly with very high androgen levels should immediately alert you to neoplasm (adrenal or ovarian tumors), requiring urgent imaging and endocrine evaluation 1.
Non-Hormonal Causes (Rare but Important)
These present with clitoromegaly without clinical or biochemical evidence of hyperandrogenism 6, 7:
Structural/Neoplastic
- Neurofibromatosis - Involves clitoral subcutis and corpora cavernosa 3, 4
- Vascular malformations - Isolated clitoral hemangiomas or vascular malformations 8, 9
- Cysts - Epidermoid/epidermal inclusion cysts or sebaceous cysts 3, 7
- Clitoral priapism - Extremely rare; reported after appendectomy 10
- Clitoral abscess - Following female circumcision or obstetrical surgery 11
- Rhabdomyosarcoma - Rare malignant cause 9
Congenital
- Intersex states/disorders of sexual differentiation (DSD) - Present at birth with genital ambiguity 2, 6
Diagnostic Approach
When evaluating clitoromegaly, determine timing and associated features:
Assess onset and progression:
- Congenital vs. acquired (developed during puberty or later)
- Rapid vs. gradual progression
- Age at onset 6, 3
Look for virilization signs:
- Deepening voice
- Male pattern baldness (including bitemporal hair loss)
- Androgenic muscle development
- Breast atrophy
- Severe hirsutism (use Ferriman-Gallwey scale)
- Menstrual dysfunction (oligomenorrhea, amenorrhea) 1
Physical examination specifics:
- Measure clitoral dimensions (length and width)
- Assess for clitoral pain, pulsation, or tenderness
- Check for acanthosis nigricans (insulin resistance marker)
- Examine for signs of neurofibromatosis
- Palpate for masses, cysts, or abnormal consistency 1, 7
Laboratory evaluation:
- Total and free testosterone
- DHEA-S (adrenal androgen)
- 17-hydroxyprogesterone (screen for CAH)
- LH, FSH, prolactin
- Consider 24-hour urinary free cortisol if Cushing's suspected 1
Imaging:
- High-resolution ultrasound with linear transducer for clitoral anatomy
- Color Doppler ultrasound if vascular malformation or priapism suspected
- Pelvic ultrasound for ovarian masses
- Adrenal imaging (CT/MRI) if adrenal tumor suspected 10, 7
Critical caveat: If hormonal workup is completely normal, pursue imaging for structural causes including cysts, vascular malformations, and neurofibromatosis 6, 7. Many commercial laboratories provide inaccurate androgen measurements, particularly in the low-normal female range, so use a proficient laboratory with established reference ranges 1.