Abstract / Summary
Abstract Introduction: Metaplastic breast carcinoma (MBC) is a rare and aggressive subtype of breast cancer, accounting for less than 1% of all breast malignancies. Characterized by epithelial-to-mesenchymal differentiation, it frequently exhibits a triple-negative phenotype and may contain heterologous elements such as osseous differentiation. Delayed presentation and emergency surgical management remain uncommon and sparsely documented. Cases Presentation: A 54-year-old woman with a previously diagnosed breast carcinoma discontinued treatment and repeatedly refused surgery, chemotherapy, and radiotherapy for nearly two years. She subsequently presented with a giant fungating breast mass complicated by severe hemorrhagic anemia requiring urgent resuscitation. Following stabilization, an emergency radical mastectomy with en bloc resection was performed. Histopathological examination confirmed a triple-negative MBC composed of epithelial and sarcomatoid components with heterologous osseous differentiation. Complete (R0) resection with negative margins was achieved. The postoperative course was uneventful, and the patient recovered well before being discharged in satisfactory condition.
Conclusion: This case illustrates the exceptional rarity of MBC with epithelial, sarcomatoid, and heterologous osseous differentiation while providing a unique insight into its natural progression following prolonged treatment refusal. Despite advanced local disease at presentation, emergency oncologic surgery achieved successful complete resection with a favorable early postoperative outcome. The extensive clinical, radiological, intraoperative, and pathological documentation further enhances the educational value of this report and contributes to the limited literature on this uncommon breast malignancy.