I am a 1st year and having trouble coming up with diagnoses on my autopsy kidneys. It seems they often have cysts, scarring, granular appearance, stones, etc. A provided loose outline of what I am thinking and was hoping for some input. Thanks!
1. cyst with compressed parenchyma, lymphocytes, sclerosed glomeruli = renal cyst
2. patches of depressed parenchymal areas with thinned cortex or stones, sclerosed glomeruli, thyroidization, dilated tubules, lymphocytic infiltrate = chronic pyelonephritis or pyelonephritic scars if no infiltrate
3. granular apprearance, diffuse sclerosed glomeruli, hylanized arterioles = ateriolonephrosclerosis (is it always diffuse, do you ever get lymphocytic infiltrates?)
4. patchy depressed areas, lymphocytic infiltrate, fibrosis, thyroidization, sclerotic glomeruli = chronic intersitial nephritis (or would this be more diffuse instead just a few scarred inflammed areas?)
5. what about chronic glomerulnephritis? --it seems like it looks like end-stage kidney like 2 or 4?
Things to keep in mind:
1. cyst, etc: Thin-walled unilocular cortical cysts filled with urine-like fluid and having smooth interior linings -- so-called "simple renal cysts" -- are so common that I have come to consider them a variation of normal. Occasionally the fluid is cloudy or dark; sometimes you see little fibrous streaks on the interior; and these cysts can be quite large, even what some might call humongous. The adjacent kidney parenchyma may appear compressed, may have a few sclerosed gloms, may have some lymphocytes. Regardless, call them simple cysts and move on.
2. patches, etc: Sounds like small coritical scars. Also very common. I've always thought of them as small infarcts associated with hypertension and subsumed them under that heading in my autopsy diagnoses. So far that has not gotten me in trouble. The other alterternative is small infarcts associated with small emboli. Possible. But without a clear history or other indicators of such, why complicate things?
3. granular, etc: Sounds like ateriolonephrosclerosis, as you say. Often a background for (1). HTN again. Can have associated lymphocytic infiltrates. This also is very common in autopsy kidneys, esp elderly patients hospital cases who have been sick for a while. I've wondered about it too. Yet to get a clear answer. I've used the diagnosis "focal interstitial nephritis". Has worked so far.
4. patchy, ect: Sounds like a repeat of (2), just further along on the pathologic continuum.
5. what about, ect: Sounds like a repeat of (3), also further along. The older kidneys get the rattier they look. They can look pretty blown out but still function adequately. Probably age-related changes with a little superimposed "focal interstitial nephritis". Without a history of renal failure or something like that, don't overcomplicate things.
A few other things to keep in mind:
Kidneys, esp the tubules, autolyze fast and furious, second only to pancreas and maybe adrenals. So you have to look through that. (don't start giving everyone ATN.)
Small stones and occasional microscopic areas of parenchymal calcification are also pretty common. The former, if I can see them grossly, I would give a dx "renal lithiasis"; the latter I'd ignore.
If a person has been in the hospital a while, or has had a decent work up in the recent past, and their renal function was more or less OK, it is highly doubtful they will have anything seriously wrong (at least diffusely) with their kidneys. An elderly person with mild-moderate renal impairment? HASCVD associated ateriolonephrosclerosis until proven otherwise.
One other common thing to look out for is diabetes associated nephropathy. You know what that looks like, right?
