Multiple myeloma with primary amyloidosis presenting with digestive symptoms: A case report and literature review.

We present a case of multiple myeloma with primary systemic amyloidosis presenting with digestive symptoms in a 32-year-old male. Initial symptoms included upper abdominal discomfort for 4 months, and stool with mucous and blood for 1 month. Erosive gastritis, Helicobacter pylori infection, haematochezia, and weight loss were noted, but without bone pain, anaemia, or hypercalcaemia. Bone marrow examination showed 18.5% mature monoclonal plasma cells that were λ light chain protein and CD38 positive. Three courses of 28-day PTD therapy (i.e., bortezomib, dexamethasone, and thalidomide) were administered. Gastrointestinal symptoms and laboratory parameters improved. Post-treatment follow-up showed 0.5% plasma cells with normal morphology in bone marrow, urine λ light chain 10.1 mg/L, and negative M protein. Nevertheless, the patient died of multiple organ system failure 8 months after treatment. CONCLUSIONS: Amyloidosis is an uncommon finding in patients with multiple myeloma, especially in younger individuals.