Breast metastases from extramammary malignancies are rare and usually associated with a poor prognosis with the prevalence fluctuating from 0.5% to 6.6% of all malignant tumours in the breast [1 - 5]. They are however important to diagnose in order to target treatment and determine management strategies. The purpose of this study was to retrospectively identify the incidence and imaging features of breast metastases from extramammary malignancies presenting to an Australian rural practice.

Breast biopsy records from January 2008 to December 2019 were retrospectively reviewed. During this twelve-year period, more than 1,000 breast cancers were diagnosed, nine of which were breast metastases from extramammary malignancies. Secondary breast metastases from lymphoma and malignant intramammary lymph nodes from non-breast primary tumours were also included in this study. Metastases to axillary lymph nodes along with primary tumours of the skin were excluded from the study. All imaging studies were retrospectively reviewed by a consultant radiologist with more than twenty years of...

Patient Data Over the twelve-year period, 1,060 breast cancers were detected and of these nine were identified as being breast metastases from extramammary malignancies. Nine patients were included in this study with females being more commonly affected (6 females, 3 males). Mean and median onset age for breast metastasis was 62 years and 68 years, respectively, with a range of 15 years to 87 years. In this study breast metastases from extramammary malignancies were rare, accounting for only 0.85% of all malignant neoplasms of the...

Breast metastases from extramammary malignancies are unusual, however are important to diagnose in order to determine patient treatment and management. In accordance with the literature, our study demonstrates lymphoma, lung, melanoma and renal metastases are amongst the most frequently cancers to metastasize to the breast. 3. The mammographic and sonographic appearance of extramammary breast metastases are not pathognomonic of metastatic disease and biopsy is required to confirm diagnosis.

P. Neerhut: Nothing to disclose

Bitencourt A G V, et al. Breast metastases from extramammary malignancies: multimodality imaging aspects. Br J Radiol. 2017 Aug: 90(1077): 20170197. Wienbeck S, Nemat S, Lotz J, Surov A. Imaging diagnostics of breast metastases from extramammary tumors. Radiologe. 2017 Jun: 57(6):459-465. Buisman FE, et al. Non-primary breast malignancies: a single institution’s experience of a diagnostic challenge with important therapeutic consequence – a retrospective study. World Journal of Surgical Oncology 2016: 14: 166. Pen Sun, et al. Characteristics of breast metastases from non-breast solid tumours in...