[Abdominal pain: It still can be a zebra].

We describe the case of a 51-year-old patient with acute lower abdominal pain, in whom CT imaging revealed thrombosis of the superior mesenteric vein. Due to nephrotic proteinuria, elevated free lambda light chains, and echocardiographic findings consistent with cardiac amyloidosis, a bone marrow biopsy was performed. Collectively, the findings established a diagnosis of multiple myeloma with AL amyloidosis and subsequent nephrotic syndrome as the primary cause of the splanchnic thrombosis.