“…Malignant PRCL such as mucinous cystadenoma and cystadenocarcinoma, pseudomyxoma retroperitonei and solid neoplasms with cystic transformation (leiomyosarcoma, paraganglioma), are rare [5], [7], [8], [9], [10]. On the contrary, a wide variety of benign retroperitoneal cystic lesions has been described [5], [8], [9], [10], [11], [12], [13], [14], [15], such as müllerian cyst, hydatid cyst, lymphangioma, cystic mesothelioma, cystic teratoma, tailgut cyst, epidermoid cyst, post-traumatic pseudocyst, lymphocele following abdominal surgery, urinoma, hematoma and bronchogenic subdiaphragmatic cyst.…”