Neonatal asymmetrical vulvar hypertrophy: a neonatal manifestation of ’classic' prepubertal vulvar fibroma?

Unilateral vulvar swelling in a 7‐year‐old girl

“…The etiology of these lesions is not yet known, although some authors argue that prepubertal vulvar fibromas represent benign mesenchymal neoplasms 1,2 . The typical age of presentation is from 2 to 12 years, although prepubertal vulvar fibroma in the neonate has been reported 3 . Similar lesions with identical clinical presentation and histologic appearance to prepubertal vulvar fibromas have been termed “childhood asymmetric labium majus enlargement,” suggesting that these masses are simply a physiologic response of vulvar tissue to prepubertal and pubertal hormonal surges 4,5 .…”

“…Unilateral vulvar enlargement is rare in the pediatric and adolescent population. The differential diagnosis of unilateral vulvar swelling includes lipomas, vascular malformations such as hemangiomas and lymphangiomas, Bartholin gland cysts, primitive neuroectodermal tumors of the vulva, mesenchymal tumors, and Crohn disease (CD) 3,7,8 . Vascular malformations should be excluded with imaging prior to biopsy.…”