Necrobiosis lipoidica refers to the degeneration of collagen along with granulomatous response. In addition, the blood vessels are thickened and the fat deposits. The major complication of necrobiosis lipoidica is ulceration secondary to trauma. In few cases, squamous cell carcinoma may develop as a complication. The most common risk factor of necrobiosis lipoidica is diabetes mellitus. Reference: https://emedicine.medscape.com/article/1103467-overview Image via: https://en.wikipedia.org/wiki/Necrobiosis_lipoidica