Pseudoangiomatous stromal hyperplasia of the breast in two adolescent females.

The majority of breast lesions that present in adolescent girls are benign, with most being fibroadenomas. Rarely, a large and rapidly growing breast mass may be found to be the more recently described entity named pseudoangiomatous stromal hyperplasia (PASH). The pathogenesis of this lesion is attributed to hyperplasia of stromal myofibroblasts in response to hormonal stimuli. To date, PASH has rarely been described in adolescence. We describe the presentation of PASH in two adolescent patients. The first is a 12-year-old girl who found a mass in her left breast 3 months prior to presentation. An excision of an 11.5 x 10 x 3.5 cm lesion weighing 347 g was performed via breast-conserving incisions. The second patient is a 16-year-old girl who also had a rapidly enlarging left breast mass removed in a similar fashion. This mass measured 12 x 11 x 6 cm and weighed 460 g. Both tumors were noted to have a smooth capsule. Histologic appearance consisted of the typical features of PASH; fibrous stroma containing numerous anastomosing slit-like spaces; some compressed and others with discernible lumina. Both patients had complete excisions and have since not experienced recurrence. Each has had excellent cosmetic results with symmetrical breast development since their resection. Pseudoangiomatous stromal hyperplasia is a rare tumor that arises in the breast. These tumors may grow quickly and often are mistaken for fibroadenomas, phylloides tumor, or angiosarcoma. They must be resected with careful attention to resection around the capsule of the tumor with breast conservation as a goal. Long-term follow-up is necessary, as some have been reported to recur.