Breast infarction during pregnancy and lactation: A case report.

Spontaneous infarction is a rare condition associated with the physiological hyperplasia of breast tissue associated with pregnancy and lactation. The causes of and mechanism underlying the occurrence of this complication remain largely unknown. The present study describes a rare case of breast infarction occurring during pregnancy and lactation in a 20-year-old woman. At 2 months of gestation, the patient noticed a soft and painless lump (size, ~5×4 cm) in the right breast. The lump grew to eventually occupy the entire breast. The patient was hospitalized 1 month after delivery and underwent a mastectomy. Histopathological study of the resected breast tissue revealed that 90% of the breast tissue had undergone infarction, with the infarct located centrally, under the areola. Involution of the breast tissue and small focal hemorrhages were noted, along with acute or chronic inflammatory cell infiltration in the interstitial tissue. Some breast ducts showed cystic dilatation, while some small blood vessels showed dilatation and congestion. Postoperative recovery of the patient was uneventful. This was a case of breast infarction with irregular, high-grade fever. The findings of core-biopsy were inconclusive, which highlights the importance of Mammotome™ biopsy or surgical excision in the diagnosis in such cases.