Papillary endothelial hyperplasia (Masson's tumor) of the breast: A diagnostic challenge.

Papillary endothelial hyperplasia (PEH) or Masson's tumor is a rare benign vascular tumor that usually appears in the soft tissues of the head and neck, trunk and extremities, being extremely rare in the breast. Its diagnosis can be a challenge, especially in the follow-up of patients with previous disease of breast carcinoma. We present the case of a 65-year-old patient, with a history of bilateral breast cancer and reconstruction with implants, who presented a Masson's tumor during follow-up. An ultrasound scan was performed, showing a well-circumscribed mass in the left breast, located in the posterior contour of the implant. Subsequently, magnetic resonance imaging (MR) depicted an enhancing tumor, without infiltration of adjacent structures. Finally, the definitive anatomopathological diagnosis was obtained after surgical excision.