Idiopathic AL amyloidosis and biclonal paraproteinemia: a case report and review of the literature

A case of 79 year-old man suffering from nephrotic syndrome, infiltrative cardiomyopathy and sensitive neuropathy of the lower limbs, associated with biclonal gammopathy (IgG kappa and IgA lambda), is described There was a history of non-insulin dependent diabetes mellitus and of two lung nodules considered as benign lesions on the basis of cytologic, hematologic and instrumental examination. A rectal biopsy positive for amyloid deposition (Congo red histology and immunofluorescence study) led to the diagnosis of AL amyloidosis. Considering that the patient did not fulfill diagnostic criteria for lymphoproliferative diaseases (myeloma, lymphoma or Waldenstrom's macroglubulinemia), nor for secondary malignant paraproteinemia, a diagnosis of idiopathic AL amyloidosis with biclonal gammopathy was made. Very few cases of idiopathic AL amyloidosis with double component are reported in the literature. Our review suggests that idiopathic AL amyloidosis with biclonal gammopathy is similar to idiopathic AL amyloidosis with monoclonal paraproteinemia in terms of clinical features, response to therapy and prognosis. Further studies, however, are necessary to clarify the trite incidence and the clinical features of idopathic AL amyloidosis associated with biclonal gammopathy.