Ultrasonographic and Mammographic Findings of Nodular Sclerosing Adenosis

ABSTRACT

PURPOSE: To evaluate the ultrasonographic and mammographic findings of cases of nodular adenosis. MATERIALS and METHODS: We evaluated 22 lesions with a pathologically proven nodular adenosis from five hospitals for three years. We excluded adenosis cases combined with other breast diseases. The findings of ultrasonography and mammography were retrospectively interpreted in consensus by two radiologists that were experienced in breast imaging according to the BI-RADS criteria. RESULTS: The age of the patients was 29-56 years with a mean age of 43.4 years. Ten lesions were biopsied with a 14-gauge core needle, seven lesions were biopsied with an 11-gauge vacuum-assisted mammotome and five lesions were removed by surgical excision. Mammography was performed in 15 patients and distinct abnormalities were seen in seven cases. These abnormalities consisted of an indistinct irregular mass, three circumscribed masses and three focal asymmetries. Calcifications were not seen in all of the masses. Ultrasonography was performed in 22 patients, revealing 13 irregular shaped lesions 8 oval shaped lesions and one round shape lesion. The margin was either circumscribed (n = 7) and not circumscribed (n = 15) in the lesions. The orientation of mass was parallel in 13 lesions and not parallel in 9 lesions. The boundary was an abrupt interface in all of the cases. The echogenecity of the mass was hypoechoic in 15 cases, isoechoic in 4 cases, hyperechoic in 2 cases and complex echogenic in one case. Nineteen of the cases showed no posterior feature and one case showed combined features. The final categories by the BI-RADS criteria were category 3 in three cases and category 4 in 19 cases (C4a 11, C4b 8). CONCLUSION: Nodular adenosis mostly presents as category 4 on ultrasonography. Therefore, a differential diagnosis with malignancy is difficult to determine. However, the findings of lesions highly suggestive of being malignant such as a spiculation or echogenic halo, are rare. On mammography, it is commonly obscured.