Angiodysplasia of colon revisited: pathologic demonstration without the use of intravascular injection technique

The recognition of angiodysplasia either at the time of surgery or at the time of routine gross and microscopic examination has often been difficult. Until now the primary methodology used in defining the lesion has been the intravascular injection of radiopaque dyes and other compounds. This technique, however, is prohibitively time consuming and expensive, and does not encourage routine use in surgical pathology practice. We report two cases of angiodysplasia, both occurring in unlikely areas, in which the pathologic lesion was demonstrated without the use of an intravascular injection technique. One case involved 35 cm of proximal transverse colon and the other involved 23 cm of colon distal to the ileocecal valve. A simple method of demonstrating angiodysplasia by intraluminal formalin fixation (37% concentrated, unbuffered), with tying of both resected ends for 3 hours, followed by dissection of the mucosa from the muscle wall, is described. Areas of ectatic, pericryptal, thin-walled blood vessels with adjacent dilated, engorged submucosal veins are readily seen on gross direct inspection highlighted by transillumination. Histologic sections taken from these areas show early lesions of angiodysplasia characterized by ectatic, engorged submucosal veins and some dilated venules and capillaries in the mucosal lamina propria.