Objective:

To investigate the correlation between ultrasonic features and pathologic findings of hypercellular variant of mucinous breast cancer (MBC).

Methods:

The sonographic features of 11 cases with hypercellular variant of MBC were analyzed. The microscopic slides were evaluated to estimate the presence of intracellular mucin

the shape of intracellular mucin (small globules

large lake

large lake with signet ring cell) and the proportion of volume of extracellular mucin to area of tumor cell (＜30%

30%-90%

＞90%). The sonographic e

cho pattern of tumors was compared with pathologic findings.

Results:

Ultrasound showed a solid mass in all 11 cases

which was hyperechoic (5/11)

isoechoic (2/11) or hypoechoic (4/11). Eight masses had irregular shape. Eight masses had indistinct margins. Ten masses were hypervascular or isovascular. Elastography was performed in eight patients

and five masses had a elasticity score of 2 or 3. The lesions with many small intracellular mucin globules were presented as hyperechoic

while the lesions with large lake of intracellular mucin or with no intracellular mucin were isoechoic or hypoechoic. There was no correlation between sonographic echo pattern and extracellular mucin. All lesions were classified as BI-RADS category 4.

Conclusion:

The common sonographic features of hypercellular variant of MBC are irregular

indistinct and hyperechoic mass with hypervascularity and low elasticity score. The sonographic echo pattern is correlated with intracellular mucin

but not with extracellular mucin. Ultrasound is useful in the prediction of malignancy or benignancy of hypercellular variant of MBC.