=Definition.=—A pathological state of the kidney in which there is
a peculiar infiltration into the kidney structure of an albuminoid
material of a waxy appearance.
=Etiology and Pathology.=—This is associated with Bright’s disease
and other wasting diseases. It is most frequently caused by profuse
and long continued suppuration, especially of the bones, by syphilis,
tuberculosis, cancer, lead poisoning and gout.
=Pathologically=, the kidney is large and pale, but it may be normal in
size or even small, pale and granular. The capsule is not adherent, the
surface of the kidney, after removing the capsule, is pale and anemic.
On section the cortex is seen to be enlarged. It is homogeneous,
anemic, pale, waxy and resisting. On microscopic examination there is
found to be an infiltration of a homogeneous or wax-like material. This
progresses until all parts of the organ are infiltrated. As the result
of this pressure the structures of the kidney undergo an atrophic
degeneration, the kidney becoming contracted, smaller, rough and
even distorted in shape. The cortex becomes narrowed and the capsule
adherent. If a section of an amyloid kidney be stained with a solution
of iodine, numerous mahogany red points appear.
=Symptoms.=—There are similar changes in the liver, spleen and often
the intestinal canal. There is a profuse, watery diarrhea, due to
amyloid changes in the intestinal canal, with loss of flesh and
strength, edema of the lower extremities, and ascites. There is an
increased flow of pale, watery urine, of low specific gravity; albumin
is abundant and usually hyaline, often fatty or finally granular tube
casts occur.
=Prognosis.=—As a rule the prognosis is decidedly unfavorable and it
must be controlled by the disease with which it is associated.
=Treatment.=—The primary disease demands attention, otherwise the
measures of treatment indicated are those of chronic parenchymatous
nephritis, with special attention to the general health and
surroundings of the patient. Give a generous diet and be persistent
with the treatment.