An unexpected diagnosis in a renal-transplant patient with proteinuria treated with everolimus: AL amyloidosis.

Proteinuria is an expected complication in transplant patients treated with mammalian target of rapamycin inhibitors (mTOR-i). However, clinical suspicion should always be supported by histological evidence in order to investigate potential alternate diagnoses such as acute or chronic rejection, interstitial fibrosis and tubular atrophy, or recurrent or de novo glomerulopathy. In this case we report the unexpected diagnosis of amyloidosis in a renal-transplant patient with pre-transplant monoclonal gammapathy of undetermined significance who developed proteinuria after conversion from tacrolimus to everolimus.