Differential Diagnosis of a Unique Vulvar Mass in an Adolescent.

<bold>Background: </bold>Vulvar masses in adolescents have a broad differential diagnosis, yet few reports exist detailing masses of mammary origin.<bold>Case: </bold>A nulliparous, healthy 16-year-old adolescent presented with a longstanding, ulcerated, 17-cm vulvar mass of unknown origin and pronounced inguinal lymphadenopathy. The patient underwent a left radical partial vulvectomy, with pathology revealing terminal duct lobular units consistent with polymastia.<bold>Conclusion: </bold>Differential diagnosis of a vulvar mass in an adolescent should include polymastia. [ABSTRACT FROM AUTHOR]