CT of the mesocolon. Part 2. Pathologic considerations.

The anatomy of the mesocolon can be seen on computed tomographic (CT) scans, and its CT anatomy can be described by using the vessels in the mesocolon as anatomic landmarks. Knowledge of this anatomy is the basis to understanding pathologic processes involving the mesocolon. Common pathologic conditions usually occur due to spread of disease between organs to which the mesocolon is attached, primarily the colon and pancreas. The disease may be a malignant lesion, a benign inflammatory process, or, rarely, a primary tumor of the mesocolon; the mode of spread may be via the lymphatic vessels, direct extension, vascular invasion, or vascular involvement. The authors demonstrate various pathologic conditions and modes of spread, as seen on CT scans, with emphasis on disease of the colon and pancreas. The pathway for the spread of disease and its progression in these organs can be predicted in patients with a known disease. More important, identification of abnormalities in the mesocolon leads to careful evaluation of the organs to which the mesocolon is attached.