Icahn School of Medicine at Mount Sinai - NYC Health + Hospitals/Elmhurst Elmhurst, NY
Introduction: Abdominal lymphangioma is a rare finding. Most of them arise from the mesentery or omentum, and those arising from the GI tract is extremely rare. Lymphangioma involving the colon is usually asymptomatic and can be encountered during screening colonoscopy. It is characterized by a soft, cystic appearing lesion that contains dilated lymphatic channels. Cecal lesions should be differentiated from appendiceal neoplasms including mucocele and carcinoid tumors.
Case Description/Methods: A 61-year-old male underwent a screening colonoscopy which revealed a soft cystic lesion in the cecum measuring about 20 mm wide, with a positive cushion sign. Appendiceal orifice and the ileocecal valve appeared normal (a). CT of the abdomen showed a low-density cystic lesion arising from the wall of the cecum and separate from the appendix. (b). Endoscopic ultrasound (EUS) exam using a mini ultrasound probe revealed a cystic anechoic subepithelial lesion measuring (18 x 17 mm) with septations arising from the submucosa (c).
Discussion: Lymphangioma of the colon is a rare asymptomatic finding often encountered during screening colonoscopy. It is characterized by a soft, cystic appearing lesion that contains dilated lymphatic channels. It is often solitary and is usually benign in nature. Cecal lesions, especially if in proximity to the appendiceal orifice should be differentiated from appendiceal neoplasms including mucocele and carcinoid tumors. Lymphangioma may be difficult to be differentiated from a lipoma on endoscopic appearance. Signal characteristics on CT imaging differ between the two; Lipomas have characteristics similar to subcutaneous fat and usually have Hounsfield unit measurements between -65 and -120; Lymphangiomas on the other hand are cystic appearing with Hounsefield units corresponding to the fluid density and the average Hounsefield unit of the lesion in our patient was 17. Similarly, endosonographic features vary between the two. Lipomas are hyperechoic lesions arising from the submucosa, whereas lymphangiomas are anechoic. Endoscopic appearance of a cystic lesion often with a bluish hue and a positive cushion/ pillow sign and ultrasonographic features (anechoic subepithelial lesion often with septations and without solid component) aid towards the diagnosis of lymphangioma without the need for invasive tissue diagnosis. Rare cases of intussusception from large cecal lymphangioma have been reported. Given the benignity, surgical intervention is not needed in asymptomatic patients.
