Amyloid Angiopathy-related Severe Hemorrhage with Multiple Myeloma

A 64-year-old woman newly diagnosed with IgG-λ type multiple myeloma was admitted for induction therapy. At the time of admission, she presented with petechial hemorrhage of the skin despite having no abnormalities in her coagulation or platelet function test results. During hospitalization, she developed severe melena. Small bowel endoscopy revealed multiple small ulcers in the jejunum. During small bowel endoscopy, new submucosal hemorrhages appeared at the site of balloon compression (Picture 1). Jejunal biopsy with Congo red staining revealed the deposition of amyloid protein around the blood vessel wall, which was identified as apple-green birefringence under polarized light (Picture 2). In addition, skin biopsy revealed amyloid protein deposition around the small blood vessels under polarized light (Picture 3). Patients with amyloidosis often have coagulation abnormalities and a bleeding tendency; however, gastrointestinal bleeding is uncommon (1, 2). In this case, blood vessel wall fragility coupled with amyloid deposition caused severe bleeding despite the absence of coagulation abnormalities.