MALIGNANT-MELANOMA WITH RENAL DENSE DEPOSITS CONTAINING TUMOR-ANTIGENS

Abstract

A patient with disseminated malignant melanoma developed mild renal failure with proteinuria 4 mo. following the diagnosis of his neoplasm. Renal biopsy showed a membranoproliferative glomerulonephritis. EM revealed intramembranous dense deposits in the glomeruli as well as in tubular basement membranes and Bowman''s capsule. Immunofluorescence microscopy demonstrated granular staining for C3 [complement component 3] in these same locations and granular deposits of immunoglobulins in the glomerular capillary loops. Light microscopy and EM of the autopsy kidney obtained 5 mo. later revealed progression of the number, size and density of the deposits. Eluates from both autopsy and biopsy kidney contained melanoma antigen and anti-melanoma antibodies. This case illustrates the association between the dense deposits and neoplasia with the dense deposits representing immune complexes with the tumor as antigen.