Breast fibroadenoma:comparative study of pathological features with varied MRI findings / 中华放射学杂志

ABSTRACT

Objective To identify histopathologic correlates for the various MRI appearances of breast fibroadenomas.Methods Thirty-eight fibroadenomas in 33 patients(aged 24—57 years)examined with gadolonium-enhanced MR imaging were observed for signal intensity on T_2-weighted images,contrast enhancement,shape,and internal septation,and these findings were correlated with histopathologic findings.All cases underwent surgery and were proved by pathology.Results(1)The lesion shape was lobular,or round in 34 of 38 fibroadenomas(89.5%).(2)The signal intensity on T_1-weighted images was less than or equal to that of fibroglandular tissue in all cases.The signal intensity on T_2-weighted images was highly variblehigh T_2 signal intensity was associated with more myxomatous stromal(mean myxoid-sclerotic index value of 1.9),higher stromal cellularity(mean stromal cellularity index value of 2.2); Fibroadenomas with low T_2 signal intensity had stromal that was nearly uniformly sclerotic(mean myxoid- sclerotic index values of 2.8)and low stromal cellularity(mean stromal-cellularity index value of 1.2). Significant differences were found between these two groups,x~2=11.267 and x~2=10.415(P0.05).The degree of contrast enhancement was proved to be related to ages of patients.The enhancement was more intensely in younger patients.(5)Internal septations were identified within nine of 33 enhancing fibroadenomas (27.3%)and appeared to correlated with collagenous bands at histopatholigic analysis.Conclusions Fibroadenomas demonstrate marked histopathologic variability.The resultant variability in the MR appearance correlated with the degree of myxomatous or sclerotic and stromal cellularity.Lobulation and internal septation,which appear to reflect intrinsic growth patterns of fibroadenomas,may provide more reliable information for distinction.Familiarity with the diagnostic features would facilitate to make the differential diagnosis correctly.