Proteinaceous (angiocentric sclerosing) lymphadenopathy: a polyclonal systemic, nonamyloid deposition disorder.

Proteinaceous lymphadenopathy with hypergammaglobulinemia (PLWH) is an exceedingly rare disease of unknown etiology. Described primarily as a pathologic entity, relatively little is known about its clinical manifestations or its response to therapy. The disease is often referred to and treated as an unusual form of plasma cell dyscrasia or light chain deposition disease. We have recently encountered a young patient with PLWH who presented with generalized lymphadenopathy, marked liver function abnormalities, hypocomplementemia, cryoglobulinemia, decreased T4/T8 ratio, and ophthalmopathy. Contrary to the notion that PLWH is a clonal disorder, we found no evidence of clonality in this patient. The most characteristic finding in this and in another patient, previously seen at our institution, was marked angiocentric hyaline sclerosis of the small and mid-sized blood vessels of involved lymph nodes and organs. Based on these findings, we propose the term angiocentric sclerosing lymphadenopathy, which more accurately defines this clinicopathologic entity that appears to be distinct from light chain deposition disease and other plasma cell dyscrasias.