Spleen in amyloidosis. Gross specimen of the spleen of a patient with amyloidosis, a disease in which the protein amyloid accumulates in tissues and organs. This spleen is much larger than a healthy spleen, a condition called splenomegaly. As well as the spleen, the liver, heart and kidneys can be affected by the disease. It sometimes occurs without an obvious cause, but usually it occurs during another disease, such as tuberculosis or rheumatoid arthritis. Symptoms depend on the organ affected, and it can be fatal if heart function is impaired. There is no cure, but treatment of any underlying disorder may halt the process.