'Venetian blinds' artifact in dermatohistopathology

The 'Venetian blinds' artifact is an uncommon tissue cutting artifact that leads to the formation of parallel series of strips of tissue separated from one another by narrow clear spaces. It has been attributed to either hardening of the tissue in the paraffin block or defective assembly of the microtome knife. This artifact occurs in both inflammatory and neoplastic conditions in which there are nodular collections of cells and may reflect vibration-induced disintegration of fragile cellular aggregates that lack dermal stromal support. At scanning magnification, it serves to draw the histopathologist's eye to the site of pathology.