Figure 2.

Isolated primary amyloidosis of the intestine (case report): (a - e) Colonic mucosa with deposition of pale eosinophilic amorphous material (star) in the submucosa with abundant deposits of pink amorphous materials with some cracking artifacts, characteristic of amyloid. Focal surface mucosal ulceration is noted. The background mucosa shows focal active inflammation, including cryptitis (arrow), and there is patchy crypt distortion. No granulomas are seen (hematoxylin and eosin: (a) × 20, (b) × 40, (c, d) × 200, and (e) × 400). (f, g) Congo red stain which reveals the characteristic salmon-pink color, confirming the presence of amyloid deposits (Congo red, (f) × 200 and (g) × 400). (h, i) The deposits exhibit characteristic apple-green birefringence under polarized light (Congo red under polarized light ((h) × 200 and (i) × 400).