An 18-year-old woman with a 34-cm metaplastic breast carcinoma.

Metaplastic breast carcinomas (MBCs) are rare malignancies usually with poor prognosis. We report a case of an 18-year-old African female patient who presented with a 34-cm tumor on the right breast. Biopsy showed an extensively necrotic MBC negative for estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2 (triple negative). A modified right radical mastectomy was performed, followed by adjuvant chemotherapy. Histology confirmed a widely necrotic undifferentiated malignant tumor, with strong and diffuse expression of vimentin and B-cell lymphoma 2, focal high-molecular- weight keratins and focal CD34 expression; Ki67 was >90%. There was no skin, deep margin or lymph node involvement. Six months after surgery, the patient showed a 9 x 7 cm nodule adjacent to the suture and adherent to the anterior chest wall. The tumorwas considered unresectable and the patient evolved with rapid systemic deterioration. The patient had a progression-free survival of 6 months and overall survival of 9 months.