Two Cases of Nodular Cystic Fat Necrosis Possibly Related to Previous Trauma

Nodular cystic fat necrosis, first described by Przyjemski and Schuster, is a peculiar form of encapsulated necrosis of subcutaneous fat characterized by totally or near-totally encapsulated necrosis of fatty tissue in which clusters of nonviable adipocytes are surrounded by condensed fibrous tissue. We report two cases of nodular cystic fat necrosis associated with history of trauma about the site of the lesion. Each lesion was a subcutaneous movable nodule on buttock (case 1) and shin (case 2) which has evolved over months. Both cases showed possible relation to multiple intramuscular injection or direct trauma injury. Pathologically, encapsulated nodule showed a characteristic feature of nodular cystic fat necrosis which composed of the ghosts of anucleated adipocytes showing fairly well-preserved outline.

A Case of Encapsulated Fat Necrosis / 대한피부과학회지

Encapsulated fat necrosis is a distinct, benign subcutaneous lesion characterized by histologically non-viable adipose cells surrounded by thin fibrous capsules. We report a case of encapsulated fat necrosis in a 30-year-old woman who had one mobile, subcutaneous nodule on her left shin for 3 years without previous history of trauma. Histopathologically the nodule showed strong PAS positive necrotic adipose tissues encapsulated by fibrous tissue.