Few clinicians are in much doubt as to what a histopathologist's diagnosis of leukocytoclastic vasculitis means. Few histopathologists are in much doubt as to how to make this diagnosis. If one finds, on microscopic examination, that there are neutrophils in and around the walls of cutaneous venules, accompanied by deposits of fibrin in vessel walls and by neutrophilic nuclear dust, there is a clear meaning to these changes. One can look for ancillary clues (eg, fibrosis in the case of erythema elevatum diutinum and granulomas interstitially in Wegener granulomatosis), but the basic path to a specific diagnosis has been laid out many times.
LeBoit PE. The Enigma of Lymphocytic Vasculitis. Arch Dermatol. 2008;144(9):1215-1216. doi:10.1001/archderm.144.9.1215