Subcutaneous pseudomembranous fat necrosis: new observations/linkr>

Abstract

Our series provides data suggesting that pseudomembranous fat necrosis represents a dynamic process that varies according to the evolution of the lesion at the time of the biopsy. In biopsies taken from early foci of panniculitides pseudomembranes show vescicular or picnotic nuclei. Later, pseudomembranes retain their crenulated appearance but lack nuclear elements. Furthermore, we present histopathologic, histochemical, and immunohistochemical evidence that pseudomembranous fat necrosis results from the interaction of residual products of disintegrated fat cells and macrophages. Histiocytic markers such as CD68 and lysozyme may be used as reliable tools in order to detect pseudomembranes in panniculitides.

An Unusual Case with Membranous Lipodystrophy in a Hypertensive Patient with Transepidermal Elimination

“…Later, similar membranous lipodystrophy and lipodystrophy-like changes were observed in the subcutaneous tissue of patients with chronic arterial disturbances, suggesting that these changes, although not specific to a particular disease, were related to vascular impairment of the fatty tissue 5-8. They can be associated with vascular disease, e.g., arterial vascular insufficiency to the lower legs, varicose veins, thrombophlebitis, deep venous thrombosis and stasis dermatitis.…”

Lipodermatosclerosis: A clinicopathological study of 25 cases

“…In previous reports, lipomembranous fat necrosis was found in roughly decreasing order of frequency, in erythema nodosum, morphea, traumatic panniculitis, lupus panniculitis, and necrobiosis lipoidica among many others. 4,16,18 In these studies, lipodermatosclerosis was the most common diagnosis in which lipomembranes were identified. In addition, when biopsy specimens of lipodermatosclerosis and erythema nodosum were compared, it was noted that the membranocystic fat necrosis in erythema nodosum consisted of small isolated foci that were mainly located in the fibrous septa, often associated with radial granulomas, in contrast to the prominent intralobular changes typically seen in lipodermatosclerosis.…”

“…They are thought to be caused by the interaction of residual products of disintegrated adipocytes and macrophages and may be a result of ischemic injury to adipose tissue. 18,19 Lipomembranes are classic but not definitive for the diagnosis of lipodermatosclerosis and can be found in numerous other conditions, mainly those resulting from arterial ischemia or venous insufficiency. In previous reports, lipomembranous fat necrosis was found in roughly decreasing order of frequency, in erythema nodosum, morphea, traumatic panniculitis, lupus panniculitis, and necrobiosis lipoidica among many others.…”

Lymphocytic panniculitis: an algorithmic approach to lymphocytes in subcutaneous tissue

“…Unfortunately, the characteristic lipomembranous change is not a specific feature and can also be seen in chronic or resolving lesions of EN, deep NL, morphea, LEP, cold panniculitis (CP), postirradiation panniculitis and vascular compromise of multiple causes (calciphylaxis, vasculitis, thrombophlebitis or thromboembolic disease) 3 37 38. If the only histological feature of note on biopsy sample is lipomembranous change, careful correlation with the clinical presentation is required.…”