Multimodality Imaging Findings of Breast Metastases from Malignant Melanoma: A Case Series

Breast metastases stemming from extramammary malignancies are rare, occurring in approximately 1.3–2.7% of breast malignancies. The most prevalent are metastases belonging to the primary carcinoma of the contralateral breast, followed by lymphoma and malignant melanoma. Breast metastasis is to be suspected in patients with previous history of malignant melanoma who present with a breast mass. Distinguishing metastasis from primary breast neoplasms is a challenging task. Accurate diagnosis is crucial because the prognosis and management differ significantly between primary and secondary malignancies of the breast. Imaging features are non-specific on mammography and ultrasound. There have been several reports on the magnetic resonance imaging (MRI) characteristics of breast metastasis originating from malignant melanoma; however, only few studies have described the diffusion weighted imaging (DWI) feature and the apparent diffusion coefficient (ADC) value. In this study, we report the multimodality imaging features of three cases of breast metastases from malignant melanoma. We particularly focus on MRI findings, such as DWI feature and ADC value and compare them with the MRI features reported in the literature.