[A case of solitary adrenal metastasis from breast cancer successfully resected by laparoscopy].

A 47-year-old woman had undergone breast-conserving treatment for right breast cancer (T3, N1, M0, Stage IIIA, human epidermal growth factor receptor[ HER]-2 enriched subtype) after primary systemic chemotherapy with trastuzumab. Pathological examination revealed a quasi-pathological complete response( CR) in the breast tumor and no axillary nodal involvement. The patient then received conventional breast irradiation and adjuvant trastuzumab therapy. However, adjuvant anti- HER2 therapy was discontinued in the 19th week because of a decreased left ventricular ejection fraction( approximately 50%). A left adrenal tumor was detected by abdominal computed tomography (CT) 2 years after surgery. Positron emission tomography( PET) scans showed strong accumulation in the left adrenal gland and in the lymph node near the adrenal tumor. No other obvious lesion was detected on meticulous examination. Laparoscopic adrenalectomy was performed for diagnosis and treatment. Pathological examination of the resected specimen revealed that the tumor was a metastatic adenocarcinoma with overexpression of the HER2 protein but without expression of hormonal receptors. The patient received 12 cycles of chemotherapy with paclitaxel and trastuzumab, which was followed by trastuzumab monotherapy. However, trastuzumab monotherapy could not be continued because the left ventricular ejection fraction decreased to 50% at 24 weeks after initiation of chemotherapy. The patient has been observed since the cessation of trastuzumab, without the administration of anticancer therapy, and she continues to have a good performance status without relapse. Herein, we report a case of solitary adrenal metastasis from breast cancer, an extremely rare condition, and review the relevant literature.