Diffusion-weighted imaging reflects variable cellularity and stromal density present in breast fibroadenomas.

OBJECTIVE

To determine the underlying histopathologic features influencing apparent diffusion coefficient (ADC) values of breast fibroadenomas.

MATERIALS AND

METHODS

Biopsy-proven fibroadenomas (n=26) initially identified as suspicious on breast magnetic resonance imaging (MRI) were retrospectively evaluated. Histopathologic assessments of lesion cellularity and stromal type were compared with ADC measures on diffusion-weighted MRI.

RESULTS

Presence of epithelial hyperplasia (increased cellularity) and dense collagenous stroma were both significantly associated with lower lesion ADC values (P=.02 and .004, respectively).

CONCLUSION

Variations in epithelial cellularity and stromal type influence breast lesion ADC values and may explain the wide range of ADC measures observed in benign fibroadenomas.