A 52-year-old man was admitted to hospital because of declining renal
function. Some months previously, biopsy from a mediastinal lymph node
had shown Castleman's disease (angiofollicular lymph node hyperplasia
!. By now, a renal biopsy showed massive interstitial infiltration of
predominantly plasma cells without significant atypia. On immunostaini
ng, the plasma cells showed cytoplasmic reaction for IgG and kappa and
lambda light chains, which had also been the case with the mediastina
l lymph node. These findings were interpreted as interstitial renal in
volvement of Castleman's disease. The patient was treated with prednis
one, upon which the renal function was stabilized, but not improved. T
he attention is drawn to Castleman's disease as a possible, although r
are, cause of renal interstitial cellular infiltration.