Besides forming one of the lesions in acute Bright's disease, this is liable to occur in acute febrile diseases. There is a general enlargement of the renal epithelium with infiltration of fine granules in the midst of which minute fat drops are scattered (Fig. 437). The pyramidal tubules as well as those of the cortex are involved, the affection being usually homogeneously distributed. It is important to note that this condition may produce considerable enlargement of the kidney without obvious change in its structure to the naked eye.