There have been many articles on the subject of panniculitis in medical literature. Numerous cases have been reported in which fat and muscle were involved but few in which fat alone was the seat of this painful, inflammatory process. This condition is characterized by the appearance of painful nodules in the subcutaneous fatty tissue, sometimes having the clinical aspects of erythema nodosum and resulting in localized destruction of fat with replacement by fibrous tissue and production of nodules either plainly visible or, if not visible, easily felt. Weber and Gray1 in 1924, Weber in 19252 and Christian3 in 1928 published cases similar to the one that we record here. REPORT OF A CASE History.— Mrs. K. S., aged 41, a Canadian nurse, retired, who had served during the World War, complained that frequently since 1918 painful nodules had appeared on the outer parts of