Fig. 1.

43-year old man with small bowel volvulus induced by mesenteric lymphangioma.

A. Erect abdomen image at second visit to emergency room shows inverted U-shaped and markedly distended small bowel with air-fluid level in upper abdomen. Paucity of colonic gas is also noted.

B. Axial CT scan at pelvis level shows lobulated, fluid-attenuating mass (arrows). Mass closely abuts on small bowel loops. Note engorged mesenteric vessels.

C, D. Serial axial CT images at level of iliac artery bifurcation show whirling of small bowel and mesenteric vessels around superior mesenteric artery (solid arrows). Small bowel loop at left side tapers with beaked appearance and there are collapsed bowel loops within whirling (open arrow on D).

E-G. Serial, 3 mm thick, reformatted coronal images clearly demonstrate closed-loop obstruction caused by small bowel volvulus. Marked dilatation of fluid-filled small bowel loop in epigastric area is tapered with beaked appearance (solid arrow on E) and this eventually collapsed (open arrows on E and F). This collapsed bowel continued to bowel loops abutting on cystic mass in pelvic cavity (long arrows on F and G). Mesenteric aspect of mass (asterisk on F) invaginates into whirling, with intervening thin fatty layer (arrowheads on F).

H. Clinical photograph taken during laparotomy reveals large lobulate mass arising from mesentery of small bowel loops. Torsion of mass and resultant volvulus of connected mesentery and small bowel are seen.

I. Photomicroscopy (Hematoxylin & Eosin staining, ×40) of representative section shows multiple loculi with endothelial linings and thin fibrous walls. Mass was diagnosed as mesenteric lymphangioma.