Breast MRI in detecting primary malignancy of patients presenting with axillary metastases and negative X-ray mammography / 中华放射学杂志

ABSTRACT

Objective To evaluate the role of breast MRI in detecting the primary malignancy in patients presenting solely with axillary lymph node metastases. Methods Thirty-three patients with axillary lynph node metastases but negative findings on either physical examination or mammography underwent breast MRI to identify occult breast carcinoma. MRI of the breast was assessed according to BI-RADS criteria. The pathologic diagnosis was made according to the standard criteria by the WHO Classification of Tumor. Results Among 33 patients presenting solely with axillary metastases, 30 patients underwent modified radical mastectomy. Primary breast carcinoma was proven in 17 patients. MRI detected lesions in 16 patients, including 10 masses and 6 non-mass lesions. Size of the masses ranged from 0. 5 to 2. 6 cm (mean 1.5 cm). Six lesions were smaller than 1.5 cm in size. Non-mass lesions showed ductal enhancement in 4 cases and segmental enhancement in 2 cases. One patient with tumor detected by histopathology showed no abnormal enhancement on MRI. No tumor was found at mastectomy in the other 13 womeu, and negative MR findings were revealed in 9. Four cases with suspicious enhancement on MRI had no corresponding primary foci on pathology. Three patients didn't undergo surgical procedure. The sensitivity, specificity, and accuracy of MRI in the diagnosis of the primary malignancy were 94. 1%,69. 2%, and 83.3%, respectively. Conclusions Small size of mass and ductal or segmental enhancement of non-mass lesion were common MR features of occult malignancy. MRI showed high sensitivity and accuracy in diagnosing occult breast carcinoma. Breast MRI should be taken in search of occult malignancy in patients with axillary metastases.