Calciphylaxis: how specific are the pathological features: avoiding false-positives and false-negatives

Calciphylaxis is considered a critical inflammatory dermatosis with potentially devastating clinical consequences. Skin biopsies are expedited for evaluation and are often considered as a gold standard for diagnostic confirmation and exclusion of other conditions. The key histopathological features include a combination of vascular and extra-vascular calcifications, intravascular microthrombi, and changes related to resulting ischemia. The pathological diagnosis of calciphylaxis is not always a straightforward process as it can be influenced by a number of factors. The specificity of pathological diagnosis of calciphylaxis has been questioned and a systematic approach with multidisciplinary collaboration is required to avoid potential errors.