Pseudoangiomatous stromal hyperplasia. A case for bilateral mastectomy in a 12-year-old girl.

Pseudoangiomatous stromal hyperplasia (PASH) is a benign proliferation of breast stromal cells with a complex pattern of interanastomosing spaces lined by myofibroblasts and is most commonly seen in women of child-bearing age. PASH is a frequent incidental microscopic finding in breast biopsies. Nodular PASH, however, resulting in a clinically appreciable mass and rapid growth is a rare entity, with only four such patients cited in the literature. Surgical excision results in a cure in the majority of cases, with a recurrence rate of approximately 7-22%. We report a case of a 12-year-old girl with nodular PASH who presented with bilateral breast enlargement refractory to surgical excisions, eventually requiring bilateral mastectomies. To our knowledge, our patient is the youngest patient to have nodular PASH and to undergo bilateral mastectomies.