Systemic amyloidosis associated with pleomorphic sarcoma of the spleen and remission of nephrotic syndrome after removal of the tumor

We report a case of a 57-year-old woman who was diagnosed with a systemic AA amyloidosis associated with a pleomorphic sarcoma of the spleen. Although the association and causality between chronic inflammatory states and systemic AA amyloidosis have been well established, the evidence linking solid malignancies to reactive AA amyloidosis is scarce. Our patient had a significant systemic amyloid deposition including biopsy-proven renal and cardiac AA amyloidosis. Subsequent evaluation uncovered the presence of a large splenic mass, which was treated by splenectomy. Histologically the splenic tumor was classified as pleomorphic sarcoma. The removal of the tumor resulted in a marked decline in proteinuria, stable renal and cardiac functions, and symptomatic improvement at 1-year follow-up. Based on the noted improvements, we speculate that the pleomorphic sarcoma of the spleen caused secondary amyloidosis in our case. Stromal tumors, although rare, may be associated with and should be considered in the differential diagnosis of the cause of AA amyloidosis.