Abstract
ALK-negative anaplastic large cell lymphoma is a well-established hematologic complication of prosthetic breast implantation, but other rare conditions should also be considered. We report a case of a 36-year-old female with bilateral retropectoral breast implants since age 20 who presented with fatigue, lower extremity edema, fevers, and a slowly growing left breast mass. Ultrasound of the left breast revealed a 6 × 6 cm left upper quadrant mass. Surgical excision identified pathologic features consistent with hyaline-vascular unicentric Castleman disease (UCD). This is the first case of breast-implant associated UCD, expanding the differential diagnosis for masses associated with prosthetic breast implantation.