Zalla M J, Winkelmann R K, Gluck O S
Department of Dermatology, Mayo Clinic Scottsdale, AZ 85259, USA.
Dermatology. 1995;191(2):149-53. doi: 10.1159/000246535.
Involutional lipoatrophy is an apparent idiopathic lipoatrophy with characteristic histopathologic features. We report a patient with a distant history of intramuscular injections and subsequent typical involutional lipoatrophy in whom macrophage invasion of the fat was prominent. Light microscopy revealed small, thin lobules of fat with focally prominent blood vessels and a variably hyaline background. Macrophages containing granular acid mucopolysaccharide material were present in direct apposition to lipocytes, around involuting lobules and between collagen fibers in the neighboring dermis. Focal deposits of iron were observed. Electron-microscopic examination revealed macrophages abutting lipocytes and containing lipid droplets, clear vacuoles and lysosomes in varying proportions. Lipocytes varied in size. The lipid appeared normal in most, but scattered cells contained electron-dense granules or needle-shaped clefts within the lipid. We speculate that previous injections in our patient stimulated a macrophage response, with subsequent regression of lipocytes of the neighboring fat lobules.
involutional脂肪萎缩是一种明显的特发性脂肪萎缩，具有特征性的组织病理学特征。我们报告一例有肌肉注射史且随后出现典型involutional脂肪萎缩的患者，其脂肪组织中巨噬细胞浸润明显。光镜检查显示脂肪小叶小而薄，血管局灶性突出，背景透明变性程度不一。含有颗粒状酸性粘多糖物质的巨噬细胞直接与脂肪细胞相邻，围绕退化的小叶，并存在于相邻真皮的胶原纤维之间。观察到局灶性铁沉积。电镜检查显示巨噬细胞与脂肪细胞相邻，含有不同比例的脂滴、清亮空泡和溶酶体。脂肪细胞大小不一。大多数脂肪细胞中的脂质看起来正常，但散在的细胞在脂质内含有电子致密颗粒或针状裂隙。我们推测，该患者先前的注射刺激了巨噬细胞反应，随后相邻脂肪小叶的脂肪细胞发生退化。
