Relapsed Bilateral Gigantomastia Caused by Pseudoangiomatous Stromal Hyperplasia after Reduction Mammoplasty

Gigantomastia is an abnormal proliferation of breasts by excessive mammary tissue. Pseudoangiomatous stromal hyperplasia (PASH) is a rare benign disease due to non-specialized fibrous mammary stroma. The incidence of gigantomastia caused by bilateral diffuse PASH is extremely rare. The authors experienced a unique case of recurrent PASH-caused gigantomastia after reduction mammoplasty. Recurrent PASH-caused gigantomastia has never been reported in the literature so far. A 33-year-old woman who suffered of gigantomastia underwent bilateral reduction mammoplasty 4 years ago. Recurrence occurred, and she visited our department. Both breasts were dense without palpable mass. Mammography revealed extremely dense breasts with a bilateral complex glandular pattern. Mastectomy with Wise-pattern incision line was performed. Nipple was reconstructed at the same time using the triangular skin flaps. Pathologic examination revealed numerous slit-like stromal clefts lined by endothelial-like spindle cells were present in well demarcated nodules and diffuse hyperplastic stromas. The finding was consistent with PASH. Reconstruction of aesthetic breast was impossible due to thinned remaining skin and subcutaneous fat tissues. Nevertheless, patient was satisfied, for her anxiety about relapse and discomfort was gone.