Renal involvement in malignant histiocytosis. An immunoperoxidase marker study.

In two patients who had malignant histiocytosis, renal involvement was present at an early stage of their diseases and consisted clinically of proteinuria and renal failure. The associated renal lesion was characterized by a diffuse and global endocapillary hypercellularity of the glomeruli imputable to atypical cells occluding the capillary loops. Immunoglobulins were absent from this lesion. The atypical cells were positively identified by lysozyme immunoperoxidase study as malignant histiocytes. It is suggested that renal biopsy complemented by marker study could play a role in the diagnosis of malignant histiocytosis.