A rare tumor of the breast, phyllodes tumor is uncommon in pregnant women, and spontaneous infarction of this tumor has not been reported to date. Infarction develops in malignant tumors of the breast, but the mechanism and pathogenesis of this complication is not fully understood. Breast tumor infarction in pregnant women is uncommon, except in cases of fibroadenomas. The authors report a case of spontaneous infarction of a benign phyllodes tumor in a 30-year-old postpartum woman that exhibited rapid growth during late pregnancy; this is followed by a discussion of imaging findings.
