Lipomembranous fat necrosis of the subcutaneous tissue − a distinct entity with diverse etiologies: A case report with review of the literature

Lipomembranous fat necrosis (LFN) is a term used to describe a distinctive alteration of the fatty tissue, which may be primary or associated with other systemic diseases. It is characterized by fatty cysts of various sizes in the subcutaneous tissue lined by a wavy eosinophilic hyaline membrane, forming pseudopapillary membrane projections into the cysts. This specialized type of necrosis of the adipose tissue has been reported as a focal phenomenon and, rarely, as an extensive one in several pathologies of the subcutaneous tissue. We describe a case of a 41-year-old female with systemic sclerosis who was incidentally also found to have venous insufficiency, who presented with painful dark raised lesions over both legs associated with thickening of the subcutaneous fat tissue. Biopsy and histopathological examination revealed LFN with features of stasis dermatitis. Through this case report, we discuss the clinicopathological features of this phenomenon to highlight this presentation of LFN in association with two predisposing conditions, to review the associated literature and to postulate the pathogenic mechanisms leading to this phenomenon.