RESUMO
INTRODUCTION: AL amyloidosis is the most common type of systemic amyloidosis and is caused by the deposition of an amyloidogenic protein composed of immunoglobulin light chains produced by a clonal population of plasma cells. CASE REPORT: We report the case of a 77-year-old woman with arterial hypotension, peripheral edema and renal failure. Electrocardiogram reveals low voltage on peripheral leads. Echocardiogram shows normal values for left ventricle size with increased wall thickness and cardiac wall reflectance with ground glass appearance. Serum immunofixation electrophoresis (IFE) is negative while urine IFE detects type monoclonal light chains. Abdominal Fat Pad biopsy is positive for Congo red with typical apple green birefringence after polarization under optical microscopy (OM) while ultrastructural analysis does not show presence of amyloid deposition. Two months later, the patient undergoes further worsening of general clinical condition and development of purpura in the periorbital area, at the base of the neck and in the anterior chest wall. DISCUSSION: This clinical case presents classic signs of AL amyloidosis, such as cardiac and renal involvement with the presence of a urine monoclonal component. Periorbital purpura is a pathognomonic sign of AL amyloidosis but it appears late. Final diagnosis is "AL amyloidosis with prevalent cardiac, renal and soft tissue involvement".
