The mammography and MRI manifestations of adenomyoepithelioma of the breast

AIM

To investigate mammography and magnetic resonance imaging (MRI) manifestations of benign and malignant adenomyoepithelioma (AME), in order to improve our understanding of this disease.

MATERIALS AND METHODS

Thirteen patients (11 cases of benign AME and two cases of malignant AME) were included. All patients underwent preoperative mammography, and four underwent preoperative MRI examinations.

RESULTS

Mammography revealed that 11 cases showed round, lobulate, or oval masses. One case was accompanied by calcification with blurred edges; the remaining 10 cases showed masses with clear or shaded borders. One case exhibited structurally distorted lesions, and another showed focal opacities. Among the four patients who also underwent preoperative MRI examinations, signals in the three benign cases were clearly enhanced homogeneously, and the dynamic enhancement curves were progressive. The one case of malignant AME showed an irregularly shaped mass with spiculate margins on the MRI images. The signals were homogeneously enhanced, and the dynamic enhancement curve was of the washout type.

CONCLUSION

AME usually exhibited oval or round masses with smooth edges and no calcification, and, in a portion of the cases, structurally distorted lesions or focal opacities. On different MRI sequences, AME usually showed homogeneous signal. The apparent diffusion coefficient value of malignant AME is relatively low.

Imaging features of benign adenomyoepithelioma of the breast

PURPOSE

The purpose of our study was to evaluate the imaging features of benign adenomyoepithelioma of the breast with a focus on sonographic (US) appearances.

METHODS

Ten benign adenomyoepitheliomas in 9 patients were included in this study. Mammographic and US findings were analyzed retrospectively by 2 radiologists according to the Breast Imaging-Reporting and Data System (BI-RADS) lexicon. The BI-RADS final assessment category was also recorded.

RESULTS

Of the 8 lesions for which mammography was available, 4 lesions presented with abnormal findings. Two lesions presented with an indistinct, irregular, isodense mass and a circumscribed, oval, isodense mass. The other 2 lesions presented with areas of focal asymmetry and asymmetry, respectively. On US, all of 10 lesions presented as a mass. The masses measured 0.5-1.2 cm (mean, 0.8 cm), were irregular (n = 8) or oval (n = 2) with microlobulated (n = 5), indistinct (n = 3), or angular (n = 2) margins. They were all hypoechoic, had non parallel orientation in 6 cases, and increased peripheral vascularity in 7 cases. The BI-RADS final assessment category was 4B in 6, and 4A in 4.

CONCLUSIONS

Mammographic findings of benign adenomyoepithelioma were nonspecific. An irregular, non parallel orientation, microlobulated or indistinct margin, hypoechogenicity, and increased peripheral vascularity were the most frequent US features.

Combined Epithelial-Myoepithelial Lesions of the Breast

Epithelial-myoepithelial proliferations of the breast are a heterogeneous poorly defined group of lesions characterized morphologically by dual differentiation into ductal (luminal) and myoepithelial cells. They include neoplastic and non-neoplastic entities that have overlapping morphologic features that may give rise to diagnostic difficulty. Many of these entities are low grade or of uncertain malignant potential but the biology of some of these rare lesions remains to be elucidated. This article discusses the differential diagnosis of epithelial-myoepithelial lesions of the breast and highlights the morphologic features of some of these entities.

Adenomyoepithelioma of the breast: a review stressing its propensity for malignant transformation

This review describes the classification, clinical presentation, pathological features and clinical behaviour of adenomyoepithelioma (AME) of the breast. It is based on an extensive review of the literature and study of a collection of cases built up over a 17-year period at the British Columbia Cancer Agency. The diversity of the morphology encountered in both benign and malignant AME is described. The behaviour of malignant AME seems to be related to the grade of the malignant component.