[Mixed type amyloidomas, beta2 microglobulin and AL lambda, in a long term hemodialysis patient].

A frequent complication of hemodialysis is deposition of beta 2-microglobulin amyloid in tendons and joints. Soft tissues involvement is exceptional. A 74 year-old woman on hemodialysis for 21 years developed two bilateral and symmetric tumours in gluteal regions causing discomfort when sitting. Histology, immunohistochemistry and electron microscopy showed that deposit consisted of predominant beta 2-microglobulin and lambda light chain. This is an unusual localisation of amyloidosis developing late in the course of hemodialysis. It may be perhaps initiated by chronic traumatism and be promoted by the light chain lambda of immunoglobulin.