Chronic glomerular microangiopathy and metastatic carcinoma

Two patients with metastatic colonic adenocarcinoma developed deterioration of renal function six and nine months after the diagnosis of malignant disease. A renal biopsy specimen in one case and both postmortem specimens revealed thickening of glomerular capillary loops with focal reduplication of basement membrane-like material. Ultrastructural examination of all three specimens demonstrated a lucent subendothelial zone and no evidence of electron dense deposits. Antifibrinogen staining outlined most capillary loops in one case. It appears that chronic intravascular coagulation induced by the neoplasm was the major pathogenetic process involved in the production of the glomerular lesion in each case.