Abstract: 【Abstract】 Panniculitis is a group of skin diseases involving subcutaneous adipose tissues, including primary and secondary panniculitis associated with tumors and inflammations. According to patterns of inflammation and types of fat necrosis, and combined with the learning experience at Ackerman Academy of Dermatopathology, the authors summarize pathological changes in various types of primary panniculitis, and propose some diagnostic clues, hoping to provide some ideas for the pathological diagnosis of panniculitis.

Key words: Panniculitis, Fat necrosis, Neutrophils, Giant cells, Vasculitis