Adenoid Cystic Carcinoma of the Breast: A Case Series of Six Patients and Literature Review
A 33-year-old female presented with a mass in her right breast, which was discovered during self-examination. The patient underwent a right inner quadrantectomy with SLNB. Histopathologic examination of the tumor specimen after surgery showed an ACC of low nuclear grade measuring 1.6×1.2×2.5 cm and no metastasis to the sentinel lymph node (pT2N0M0). The tumor was negative for expression of ER, PR, and HER2. The patient subsequently received adjuvant chemotherapy with fluorouracil, doxorubicin, and cyclophosphamide (FAC), followed by adjuvant radiation therapy. After 28 disease-free months, chest computed tomography (CT) showed multiple lung nodules that were suspicious for metastatic disease. The patient underwent pulmonary metastasectomy using wedge resection of the left upper and lower lobes. Histopathology indicated metastatic ACC. The largest of eight metastases measured 0.9 cm. The patient received first-line palliative chemotherapy with docetaxel every three weeks. After six cycles, response assessment showed stable disease, and chemotherapy was discontinued. Seventeen months later, chest CT showed that the lung nodules had become larger. Because of her poor overall condition, the patient received three cycles of capecitabine without further chemotherapy. She has had stable disease for the past 12 months.