Background and objective: Occult breast cancer is a kind of specific seldom clinically seen breast cancer. This study was designed to investigate the diagnosis and treatment of the patients with breast cancer.
Methods: Retrospective study was conducted in 7 cases of occult breast cancer from May 1990 to May 2001.
Results: All cases were female and account for 0.59% of the total breast cancer treated in the same period. Axillary node enlargement was presented as first sign and no breast mass was palpable in physical examination. Fine needle aspiration or excisional biopsy revealed metastatic adenocarcinoma before surgery. All cases were taken mammography and 1 case was suspicious of malignancy. 3 cases were taken ultrasonography and 1 case was suspicious of malignancy. 5 cases underwent radical mastectomy and 2 cases underwent modified radical mastectomy. Pathological examination of the removed specimen found the primary breast cancer leison in 4 case and showed infiltrative carcinoma in 3 cases and intraductal carcinoma in 1 case. After surgery, 2 cases received radiotherapy plus chemotherapy, 5 case received chemotherapy and 4 case received tamoxifen therapy. All case were still alive and 3 cases survived over 54 months and 1 case survived for 7 years.
Conclusion: Occult breast cancer should be considered when axillary lymph node is enlarged in female. Fine needle aspiration and excisional biopsy are helpful in pathologic diagnosis preoperatively. Mammography and ultrasonography have low sensitivity in identifying primary tumor. Radical or modified radical mastectomy with adjuvant radiotherapy and chemotherapy is a suitable choice for the patients with occult breast cancer and the prognosis is superior or similar to those patients who with palpable mass both in breast and axillary.