Prepubertal vulval fibroma with a coincidental ectopic breast fibroadenoma: report of an unusual case with literature review.

Prepubertal vulval fibroma and ectopic breast fibroadenoma of the vulva are two rare tumors, and they are very difficult to distinguish from other vulval masses, both clinically and pathologically. The complication of the two diseases is extremely rare. We report the case of an extremely large and progressively enlarging mass in the vulva of an 18-year-old Chinese girl. The mass was excised completely and pathologically diagnosed as a prepubertal vulval fibroma and ectopic breast fibroadenoma. The patient was followed up for 10 months and no evidence of recurrence was observed. Prepubertal vulval fibroma and vulval ectopic breast fibroadenoma should be considered in their preoperative differential diagnosis of a vulval mass, especially in prepubertal girls. Pathologically, immunohistochemical staining for vimentin and CD34 is valuable for diagnosis. Complete surgical excision is effective and long-term follow up is necessary.