The cytopathology of a lipogranuloma of external origin is reported in the eyelid of a 32-year-old man excised 1 year following regional exposure to an explosion of hydraulic oil under high pressure. The foreign lipids were still present in chronic lipogranulomas with intercellular lipidfilled cysts surrounded by macrophages and giant cells containing intracellular lipid-filled vacuoles. These indicate efforts in storage and very slow digestion. Secondary fibrosis in the region of the lipogranuloma was an important associated process. In view of the widespread technical use of hydraulic oily fluids under high pressure, it is recommended that these fluids be biodegradable.