Rare presentation of primary (AL) amyloidosis as gastrointestinal hemorrhage without systemic involvement

Figure 1 Small bowel biopsies with multiple immunostains confirming amyloid deposition. A: Duodenal Biopsy; Congo Red (× 20); Infiltration and expansion of the lamina propria and submucosa by amyloid deposition staining positive for Congo-Red; B: Small Bowel Biopsy; Crystal Violet (× 40); Marked acute duodenitis with blood, fibrin, and acute inflammatory exudates, suggestive of bleeding site. Crystal Violet stain positive for amyloid.

Figure 2 Second segment of the duodenum demonstrating notched mucosal appearance.

Figure 3 Colon Biopsy; Congo Red (× 40). Fragments of colonic mucosa and separate fragments of submucosa with eosinophilic material deposited around blood vessels, consistent with amyloid deposition. Congo Red stain positive.