Not Your Typical Cyst: A Periduodenal Chylous Cyst Diagnosed via Endoscopic Ultrasound.

Chylous mesenteric cysts represent a subgroup of uncommon, mostly benign intra-abdominal masses often identified incidentally on radiographs. Diagnosis is often challenging because these lesions cannot be reliably distinguished from hematomas or other cystic lesions without direct tissue sampling. In addition, data remains scarce regarding nonsurgical diagnostic and therapeutic options for these cysts. This case describes an endoscopic option for a uniquely located chylous cyst.