Phyllodes Tumor of the Breast Complicated With Mastitis

One of the rarest fibro-epithelial neoplasms of the breast during pregnancy is the phyllodes tumor (PT). It is typically a painless, bi-phasic, and rapidly growing neoplasm that resembles fibroadenomas. It is still unclear if the neoplasm is hormone-dependent during pregnancy. It is often challenging to diagnose and treat PT. Herein, we report a case of a 30-year-old female at 31 weeks gestation who was diagnosed with a benign phyllodes tumor of her breast with concurrent mastitis. She was first seen during her third trimester where the neoplasm was around 5 cm as reported by the ultrasound (US) examination. Her biopsy report was suggestive of a PT and she was advised surgery with excision of the tumor margin, but she refused. Ten days after her delivery she presented to the emergency department with a fever and a hard, engorged, erythematous, and tender left breast. She was diagnosed with mastitis of the left breast. She then underwent incision and drainage of the left breast that drained purulent milk; additionally, large necrotic grape-like tissues were removed and were confirmed by the histopathology report as a benign phyllodes tumor of the breast.