This biopsy shows glomerular arteriolar and capillary thrombi characteristic of thrombotic microangiopathy (TMA). Immunofluorescence studies (not shown) are negative for significant glomerular or tubulointerstitial immune complex deposits.
#TeachingPoints #kidneypath #renal #pathology
Some patients with membranous glomerulopathy also have associated focal segmental glomerulosclerosis (FSGS) lesions.
#TeachingPoints #kidneypath #renal #pathology
As published decades ago by Bonsib et al. (see reference), fluorescence microscopy of eosin-stained frozen section slides can be a valuable tool in providing diagnostic clues in kidney biopsies.
#TeachingPoints #kidneypath #renal #pathology
1/ This allograft biopsy shows the characteristic features of adenovirus infection.
#TeachingPoints #kidneypath #renal #pathology
2/ Predominantly subepithelial deposits, in contrast, would be expected in most cases of membranous glomerulopathy.
#TeachingPoints #kidneypath #renal #pathology
The differential diagnosis for interstitial hemorrhage includes hemorrhagic necrosis in the setting of renal artery thrombosis, infection (e.g. herpes simplex virus, adenovirus, hantavirus, Rickettsia),...(1/2)
#TeachingPoints #kidneypath #renal #pathology
(1/3) Chronic active T cell-mediated rejection (TCMR) was included in the 2017 Banff classification system for the evaluation of kidney allografts (see reference).
#TeachingPoints #kidneypath #renal #pathology
Collapsing glomerular lesions are aptly named, given the prominent “collapse” of glomerular tuft capillary loops. There is also hyperplasia and hypertrophy of overlying epithelial cells, and protein resorption droplets may be abundant (see arrow).
#TeachingPoints #kidneypath #renal #pathology
Prominent interstitial eosinophils (see arrow) are most often associated with allergic-type acute interstitial nephritis (AIN).
#TeachingPoints #kidneypath #renal #pathology
1/ This kidney biopsy is from an elderly adult patient with acute renal failure and a history of non-steroidal anti-inflammatory medication (NSAID) use.
#TeachingPoints #kidneypath #renal #pathology
(1/2) The picture shows tissue submitted for routine immunofluorescence (fibrinogen stain is shown). Careful inspection confirms that this is an artery cross section which contains abnormal intraluminal tissue elements with numerous cleft-like spaces (see arrow).
#TeachingPoints #kidneypath #renal
(1/2) The presence of peritubular capillaritis (see arrow Fig. 1) is an important component of microvascular inflammation, along with glomerulitis, in the diagnosis of active antibody-mediated rejection (ABMR).
#TeachingPoints #kidneypath #renal #pathology #nephsky #pathsky
1/ This biopsy shows the characteristic features of uric acid nephropathy (commonly known as gout), which results from precipitation of uric acid in the kidney parenchyma.
#TeachingPoints #kidneypath #renal #pathology
(1/3) Paying close attention to morphologic detail can sometimes suggest etiologic clues in cases of severe chronic renal injury. The glomerulus in this image, for example, shows near complete global glomerulosclerosis.
#TeachingPoints #kidneypath #nephsky #pathsky #renal
Cholesterol emboli involving the kidney may manifest clinically as acute kidney injury, hematuria, proteinuria (both non-nephrotic and nephrotic range), and even new onset hypertension.
#TeachingPoints #kidneypath #renal #pathology #nephx #pathx
However, the prominent IgG deposits also involving the associated arteriole in this case are an important clue that helps argue for a secondary etiology. This patient, in fact, was found to have systemic lupus erythematosus. (2/2)
#TeachingPoints #kidneypath #renal
1/ Knowing whether a patient has clinical nephrotic syndrome and knowing the degree of podocyte foot process effacement can be helpful diagnostic clues in separating “primary” from “secondary” forms of focal segmental glomerulosclerosis (FSGS).
#TeachingPoints #kidneypath #pathology #pathsky
1/ Electron microscopy can be helpful in the diagnosis of cryoglobulinemic glomerulonephritis.
#TeachingPoints #kidneypath #renal #pathology
1/This glomerulus is large! Glomerular enlargement, or glomerulomegaly, may be diagnosed when a glomerulus sectioned through the hilum fills greater than 50% of a 40x microscopic field. It is thought to be a morphologic marker of glomerular hyperfiltration.
#TeachingPoints #kidneypath #pathology
4/ Authorship of the black and white image is attributed to Rudolf Virchow [from the online digital image archive of the National Library of Medicine (resource.nlm.nih.gov/101436770)].
#TeachingPoints #kidneypath #renal #pathology
2/ They are found in patients with neurofibromatosis type 2 (NF2). The black and white clinical photograph, in contrast, shows a patient with neurofibromatosis type 1 (NF1), in which renal sclerosing peritubular nodules have not been described.
#TeachingPoints #kidneypath #renal #pathology
1/ Bile cast nephropathy is one cause of acute or chronic kidney injury in patients with liver disease (especially obstructive cholestasis). Figure 1 shows two paraffin blocks containing kidney biopsies from two different patients.
#TeachingPoints #kidneypath #renal #pathology
1/ This image (Jones silver stain) shows prominent glomerulitis in an allograft kidney biopsy, characterized in this case by increased mononuclear cells and segmental endothelial cell swelling within glomerular capillary loops.
#TeachingPoints #kidneypath #renal #pathology #pathsky
4/Evidence of light chain cast nephropathy and/or monoclonal immunoglobulin deposition disease may also be present in a given biopsy.
#TeachingPoints #pathsky #kidneypath
2/The crystals represent precipitated nephrotoxic monoclonal light chains, and unlike cases without crystals, pronase-digested immunofluorescence may be helpful in proving light chain restriction when routine immunofluorescence is negative.
#TeachingPoints #kidneypath #pathology
1/ This biopsy from a patient with massive proteinuria showed diffuse and near-global involvement of glomeruli by amorphous deposits (Fig. 1) which were Congo red positive (not shown).
#TeachingPoints #kidneypath #renal #pathology #pathsky
1/ While the trichrome stain is best known for assessing the extent of interstitial fibrosis, it is a versatile stain with many applications.
#TeachingPoints #kidneypath #renal #pathology #pathsky
1/ The differential diagnosis of acute renal failure in patients with multiple myeloma includes light chain cast nephropathy, amyloidosis, and monoclonal immunoglobulin deposition disease, among other possibilities.
#TeachingPoints #kidneypath #renal #pathsky #nephropath
1/ The image shows numerous crystalline-type mitochondrial inclusions. Morphologic abnormalities of mitochondria include abnormal size (usually enlargement), branched or concentric cristae, and various types of inclusions.
#TeachingPoints #kidneypath #renal
1/ This renal biopsy was taken from an 82-year-old man with acute renal failure and nephrotic range proteinuria. His past medical history included chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL).
#TeachingPoints #kidneypath #renal
