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Currently filtering by tag: Macrophages

A source of myoglobinuria…

rhabdomyolysis
The image shows a frozen cross section of skeletal muscle from a patient with rhabdomyolysis, which included the full clinical syndrome of muscle pain, weakness, dark urine, and markedly elevated serum creatine kinase.  The image shows three necrotic fibers engulfed by macrophages (arrow).  So what causes such muscle injury?  The broad differential diagnosis includes trauma, drugs (e.g. statins, alcohol, heroin, cocaine), toxins (e.g. metabolic poisons, animal venom), inflammatory myopathy, immune-mediated necrotizing myopathy (e.g. anti-HMG CoA reductase associated myopathy), infection (e.g. EBV, influenza), paraneoplastic myopathy, and metabolic myopathy (e.g. disorders of glycolysis, lipid metabolism, mitochondria).

Adenovirus

Adenovirus, interstitial hemorrhage and edema
This allograft biopsy shows the characteristic features of adenovirus infection. There is prominent interstitial hemorrhage and edema (Fig. 1), acute tubular injury with viral cytopathic effect and positive immunohistochemical cytoplasmic and nuclear staining for adenoviral antigen (Fig. 2), and foci of tubular necrosis (Fig. 3). The differential diagnosis for this morphology in the transplant setting includes other viral infection (e.g. polyomavirus, CMV, HSV), acute rejection, and drug-related acute interstitial nephritis.

Diagnose This! (October 9, 2017)

Malakoplakia
What is your diagnosis?     ​   ​ ​   ​   ​ ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​ ​   ​ ​   ​ ​   ​ ​     ​   ​   ​...

Malakoplakia

Malakoplakia
An adult patient in the mid-fifties with a deceased donor renal transplant for three years (primary disease “hypertensive nephrosclerosis”) presented with a low-grade fever and a rising creatinine. Urinalysis showed hematuria and proteinuria. A transplant biopsy was performed. 1. Low power showing one relatively intact core and a second core showing diffuse replacement of the usual renal parenchyma by inflammation and fibrosis (Trichrome, 40x) 2. Mixed inflammatory cell infiltrate (Jones Silver, 400x) 3. Macrophages with PAS-positive granules (PAS, 400x) 4. Michaelis-Gutmann body (H&E, 400x 5. Michaelis-Gutmann body (H&E, original magnification 600x) 6. Von Kossa Positive Michaelis-Gutmann bodies (von Kossa, 400x)...

Diagnose This! (June 19, 2017 )

What’s your diagnosis in this renal transplant?     ​   ​ ​   ​   ​ ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​ ​   ​ ​   ​ ​   ​ ​     ​  ...