A renal pathologist examining the day's kidney biopsies notes that one biopsy shows amorphous red nodules within the glomerular mesangium in hematoxylin and eosin stained material. Congo red stain of the biopsy demonstrates apple-green birefringence of these nodules. These nodules are most likely to be related to which of the following?
Glomerular nodules may be either the Kimmelstiel-Wilson nodules of diabetes mellitus or may be composed of amyloid. An amyloid origin can be confirmed by staining with Congo red, which causes the nodules to stain red with ordinary light but exhibit a distinctive "apple-green" birefringence when viewed with polarized light. The most common type of amyloid (type AA) is due to deposition of altered immunoglobulin light chains and is seen in diseases with chronic antigenic stimulation, such as tuberculosis. Acute urinary tract infection is an infection of too sho a duration to cause amyloidosis. Diabetes mellitus is associated with glomerular nodules called Kimmelstiel-Wilson nodules, but these will not show apple-green birefringence when viewed with polarized light. Sarcoidosis typically involves the lymph nodes, lungs, spleen, and to a lesser extent, the skin and eye. It is unrelated to amyloidosis. Ref: Wyatt C., Butterwoh IV J.F., Moos P.J., Mackey D.C., Brown T.G. (2008). Chapter 3. Pathology of the Immune System. In C. Wyatt, J.F. Butterwoh IV, P.J. Moos, D.C. Mackey, T.G. Brown (Eds), Pathology: The Big Picture.
Acute urinary tract infection
Diabetes mellitus
Sarcoidosis
Tuberculosis