Abstract
This case report describes the occurrence of a rapidly enlarging pseudoangiomatous stromal hyperplasia (PASH) tumor in a 20-year-old male patient. The diagnosis was made via tomosynthesis and ultrasound-guided biopsy with pathological correlation consistent with PASH. The patient's case was discussed, and he was recommended to undergo surgical resection of the mass to alleviate symptoms due to its large size. Surgical pathology confirmed the original diagnosis and the patient had an uncomplicated postoperative course. Here, we exhibit our imaging findings; review classic presentations of PASH on mammography, ultrasound, and MRI; and discuss histological characteristics of this benign entity.