[Tumor like presentation of primitive amyloidosis: amyloidoma]. / Forme pseudotumorale d'une amylose primitive: l'amyloïdome.

INTRODUCTION: AL-amyloidosis is a rare disease due to monoclonal immunoglobulin deposits, secondary to lymphoproliferative disorder or primitive. The deposits of amyloidosis have usually a systemic repartition. We report a tumor like presentation of amyloidosis, so-called amyloidoma. EXEGESIS: A 72-year old woman lost 10 kg within 6 months, associated with epigastric and mediastinal bulks. The biopsy of the abdominal mass showed AL-amyloidosis with kappa light chains. Since no secondary etiology could be found, the final diagnosis of primary AL-amyloidosis in a tumour like presentation, or amyloidoma, was performed. Investigations showed cardiac involvement with MRI findings, as well as kidney and bone marrow involvement. Oral melphalan as monotherapy was administered. The prognosis and the treatment of this unusual disease are discussed. CONCLUSION: Amyloidoma is a rare presentation of amyloidosis which should be evocated in front of a soft tissue mass with no clear etiology.