Abdom Imaging 19:347-348 (1994) Abdominal Imaging 9Springer-Verlag New York Inc. 1994 Mesenteric Cyst with Milk of Calcium D. Baird, M. G. Radvany, D. J. Shanley, G. A. Fitzharris Department of Radiology, Triplet Army Medical Center, Honolulu, HI 96859-5000, USA Received: 27 April 1993/Accepted: 6 June 1993 Abstract. A mesenteric cyst with milk of calcium in an adult patient is presented. Preoperative evaluation in- cluded plain film, ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI). To our knowledge, the presence of milk of calcium in a mes- enteric cyst has not been previously described. Key words: Mesenteric cyst, milk of calcium--Ultra- sound--Computed tomography--Magnetic resonance imaging. Mesenteric cysts are uncommon intraabdominal lesions, with a reported incidence of 1 per 100,000-250,000 adult hospital admissions [1]. By definition, these cysts are contained within the mesentery, histologically be- nign, and lined by endothelial cells [2]. To our knowl- edge, milk of calcium has not been reported in mesen- teric cysts. We present plain film, ultrasound, computed tomography (CT), and magnetic resonance (MR) find- ings in a patient with a mesenteric cyst containing milk of calcium. Case Report A 33-year-old man presented with recurrent episodes of mid-epigas- tric pain and tenderness associated with nausea and vomiting. Plain films of the abdomen revealed a vague circumscribed area of increased radiographic density in the fight mid-abdomen demonstrating layering of the density consistent with the presence of milk of calcium (Fig. 1). Upper gastrointestinal and small bowel series leading to colon opacification revealed no evidence of communication. Ultrasound demonstrated a cystic collection containing multiple echoes lateral to the second portion of the duodenum, which layered dependently when in the upright position. There was no apparent communication with a normal-appearing gallbladder. Contrast-enhanced CT of the abdomen revealed an oval-shaped mass lateral to the second portion of the du- odenum and abutting the right kidney, containing high-density mate- rial which layered dependently (Fig. 2A). MRI showed a mass of intermediate to high signal on Tl-weighted images and high signal on T2-weighted images, consistent with a cystic structure containing pro- teinaceous fluid (Fig. 2B and C). At surgery, a 9 • 4 cm cystic-appearing mass was identified in the mesentery of the colon at the level of the hepatic flexure. After mobilization of the colon, the mass was easily shelled out from the underside of the mesentery. The remainder of the abdominal explo- ration was unremarkable. The postoperative course was uneventful. Pathologic evaluation of the excised mass confirmed the preop- erative diagnosis of a mesenterie cyst. The cyst was filled with light tan amorphous material and had a smooth tan-pink cyst lining. The cyst wall was 0.6 cm at its thickest point without masses. This ap- pearance is consistent with a mesenteric cyst. Discussion Plain films of the abdomen and barium studies are non- specific in the evaluation of patients with mesenteric cysts [3]. Plain films may show calcification in the cyst wall or a space-occupying lesion. Barium studies may demonstrate bowel displacement. None of these features was demonstrated in the present case. Plain films of the abdomen in this case showed milk of calcium layering dependently within a structure in the right upper quad- rant, which was initially felt to represent milk of calcium layering within the gallbladder. Ultrasound has proven to be a valuable adjunct in the evaluation of mesenteric cysts [4], confirming the cystic nature of these lesions and often demonstrating internal septation. In this case, ultrasound clearly showed the lesion to be entirely separate from the gall- bladder and the biliary tree, excluding a choledochal cyst. However, the exact source of the lesion could not be ascertained from this examination. Cysts that may be encountered in the region include mesenteric or omental cysts, exophytic hepatic cysts, and pancreatic pseudo- cysts [5]. Correspondence to: D. Baird