A man in his 60s had a 6-month history of back pain and abdominal distension. He was referred to our hospital with suspected colorectal cancer as his previous doctor had identified a wall thickening in the descending colon on computed tomography as well as anemia.
Colonoscopy showed a 5-cm long submucosal tumor-like elevated lesion. A biopsy revealed amyloid deposits, and due to a lack of obvious damage in the other organs, a diagnosis of localized AL (amyloid light-chain) amyloidosis was made. Subsequently, a bone marrow biopsy revealed multiple myeloma, and the patient was transferred to the Department of Hematology for systemic chemotherapy.
In AL amyloidosis, amyloid is deposited mainly in the submucosal layer and presents characteristic endoscopic findings. In the present case, colorectal amyloidosis triggered the diagnosis of multiple myeloma.
