May 11, 2017
A PAS section shows an atheroembolus occluding an artery (arrow) with an adjacent ischemic appearing glomerulus. Atheroemboli appear as slit-like spaces in sections cut from formalin fixed paraffin-embedded sections due to the fact that the cholesterol crystals are dissolved by the lipid solvents during processing. However, as demonstrated here, the crystals can be visualized by their birefringence under polarized light in the cryosections for immunofluorescence evaluation. Atheroembolization is often preceded by in an invasive vascular procedure such as coronary artery bypass or aortic aneurysm repair though they can also be precipitated by trauma and are often idiopathic. Systemic manifestations that sometimes accompany atheroembolic disease including transient eosinophilia, skin lesions (livedo reticularis), and hypocomplementemia.