What is the differential diagnosis for cystic intra-abdominal masses not arising from solid organs?
Differentials are broad and include: Cystic lymphangioma, lymphocele, mucinous cystadenoma, Müllerian cyst, epidermoid cyst, enteric duplication cyst, enteric cyst, mesothelial cyst, nonpancreatic pseudocyst, pseudomyxoma peritonei, cystic mesothelioma, cystic spindle cell tumour, and cystic teratoma.
CT abdomen with oral and intravenous contrast shows a left lower quadrant cystic mass with rim enhancement and fluid-fluid layering. The mass is apparently separate from solid organs, located in the mesentery. There is no bowel obstruction.