A Case of Pseudoangiomatous Stromal Hyperplasia of the Breast Presenting with Chest Pain

Pseudoangiomatous stromal hyperplasia is a rare, benign, breast disease characterized by dense, collagenous proliferation of mammary stroma, forming interanastomosing capillary-like spaces. Previously reported cases presented with a palpable breast mass or continuous breast enlargement, or were unexpectedly detected on mammography or ultrasonography. However, cases presenting only with pain as the initial symptom have not been reported. In this report, we describe a case of pseudoangiomatous stromal hyperplasia that presented with intermittent dull chest pain. A 2.6 × 1.1 cm, well-defined, hypoechoic mass was noted in the breast on ultrasonography, and an excisional biopsy was performed. On pathology, the tumor showed stromal hyperplasia and vessel-like slit structures. Immunohistochemical staining for vimentin, CD34, CD31, and Factor VIII-related antigen was compatible with pseudoangiomatous stromal hyperplasia. The dull chest pain disappeared after the excision. Pseudoangiomatous stromal hyperplasia is often described as painless. However, chest pain could also be an initial symptom.