Spontaneous rupture of the spleen in AL amyloidosis.

The frequency of splenic involvement in AL amyloidosis is not precisely known. However, splenomegaly has been reported in 4-13% of patients. We report four cases of spontaneous splenic rupture in patients with AL amyloidosis. Splenic rupture was the initial manifestation of the disease in one of these patients. The other three experienced splenic rupture during or after high-dose intravenous melphalan with autologous peripheral blood stem cell transplantation (HDM/SCT): one during stem cell mobilization with G-CSF prior to HDM/SCT and two after hematopoietic recovery following treatment. Two of the four patients had Factor X deficiency, the most common coagulation abnormality associated with AL amyloidosis. All four patients underwent splenectomy without significant postoperative complications. Splenic rupture in AL amyloidosis as a complication of aggressive treatment with HDM/SCT has not been reported previously.