Occult breast carcinoma presenting with axillary lymph node metastases: follow-up of eleven patients.

BACKGROUND: Breast carcinoma presenting with axillary metastases and no clinically apparent primary tumor in the breast is an uncommon form of stage IIdisease. The methods of diagnosis and treatment of these patients are not established. We present our eleven treated cases of occult carcinoma and discuss the issues of evaluation and management.

METHODS: Eleven patients with occult breast carcinoma (OBC) presenting between January, 1985 and April, 1998 at the National Shikoku Cancer Center were evaluated clinically and with immunohistochemical staining. Immunohistochemical staining was performed using the Envision method. The primary antibodies for gross cystic disease fluid protein-15 (GCDFP-15), estrogen receptor (ER) and progesterone receptor (PR) were used.

RESULTS: Nine patients underwent mastectomy. Breast-conserving surgery was performed in one patient. One patient did not receive any operation for the breast. No primary tumor was found among three of nine cases receiving mastectomy. Some adjuvant therapies after the operation were performed in eight cases. Follow-up ranged from 5 to 310 months (median, 54 months), and the five-year disease free survival rate was 62.5%. There were eight GCDFP-15 positive cases (72.7%) and four ER and/or PR positive cases (36.4%).

CONCLUSIONS: GCDFP-15 is useful for confirming the primary site of breast carcinoma. Ultrasonography, computed tomography, and magnetic resonance imaging are thought to be good for detecting occult primary tumors. The incidence of OBC is still unclear, but it is possible that these patients need to be treated as typical stage II patients.