ESPE Abstracts

Introduction: Becker’s nevus (BN) is an epidermal cutaneous hamartoma and can be the presenting feature of a larger syndrome that includes muscle, dermatological, and skeletal findings. Although Becker’s nevi are more common among adolescent males, one specific, but rare, association in females is ispilateral breast hypoplasia hypothesized to be secondary to increased concentration of androgen receptors within the nevus.

Case Report: Patient is an 11 year-old female with a history of precocious puberty (menarche at age 9 9/12, thelarche approximately at age 8), who presented with left ipsilateral breast hypoplasia and overlying BN. Physical examination showed a moderately hyperpigmented patch without hypertrichosis or acne encompassing the lower half of the left breast. Right breast was 11 cm, glandular breast tissue while left breast was 8 cm and primarily underlying muscles. Normal female external genitalia were present (Tanner 4). Breast ultrasound showed no left breast tissue, but intact chest wall musculature. Patient was started on spironolactone 50 mg daily, dose was increased to 100 mg daily 3 months later. Breasts size after 3 months measured 13 cm on the right and 9 cm on the left. Unfortunately, 4 months post-treatment she developed spironolactone induced hypermenorrhea, thus the dose was gradually reduced to 75 mg and finally 50 mg daily by 6 months with resolution of hypermenorrhea. At 6 months post treatment, breasts re-measured 16 cm on the right and 12 cm on the left. A repeat ultrasound 10 months post-treatment confirmed interval development of left breast tissue, albeit minor.

Discussion: Recently, the relationship between androgen receptors within the BN and its association with ipsilateral breast hypoplasia has gained substantial attention given the role for medical management. The presence of androgen receptors was first reported in 1984 where a punch biopsy from a BN in the right pectoral region showed androgen receptor levels comparable to those in genital skin. More recently, staining with androgen receptor antibodies showed specificity for dermal fibroblasts within the BN. Thus, spironolactone, due to its anti-androgenic properties, can be tried in the management of BN associated ipsilateral breast hypoplasia. Our literature search yielded two similar reports of pubertal females (ages 11 and 17 years-old) who were treated with spironolactone. We also report the confirmatory post treatment imaging findings.

Conclusion: Clinicians should be aware that spironolactone presents a novel use in the treatment and de novo growth of hypoplastic breast tissue secondary to Becker’s nevus.