"Double Bubble" Sign: An Uncommon Radiologic Manifestation of a Metastatic Lobular Carcinoma of the Breast to Retroperitoneum. Issue 5 (14th July 2013) - Atmatzidis, Stefanos; Chatzimavroudis, Grigoris; Dragoumis, Dimitris; Katsiba, Daphni; Makris, John; Atmatzidis, Konstantinos