Primary systemic amyloidosis with sole cutaneous involvement

which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. A 60-year-old woman showed blackish pigmentation around both eyes for 2 years, with clinical examination revealing waxy hyperpigmentation and small nodules (A). 12.7 mg/dL; and 24-hour urinary protein, 75 mg. A peripheral blood smear showed normocytic, normochromic RBCs with rouleaux formation. Serum protein electrophoresis showed a monoclonal band in the gamma globulin region; serum immunofixation electrophoresis showed monoclonal lambda light chain immunoglobulin. Serum kappa and lambda light chain levels were 6.34 and 626.24 mg/L, respectively, with an altered kappa/lambda ratio (0.01; reference: 0.26–1.65). Radiographic results were negative. Abdominal ultrasonography revealed normal renal corticomedullary differentiation; echocardiography findings were normal. Nerve conduction velocity was normal in all limbs. Punch biopsies from periocular lesions showed amorphous pale pink dermal deposits (hematoxylin-eosin staining; B, lower magnification; C, higher magnification); Congo red staining showed apple-green birefringence on polarizing microscopy. The bone marrow plasma cell proportion was 49%. Conventional cytogenetics indicated a normal karyotype. Thus, primary systemic amyloidosis may present as isolated skin lesions.