Requena L, Yus E S
Department of Dermatology, Fundación Jiménez Díaz, Universidad Autónoma, Madrid, Spain.
J Am Acad Dermatol. 2001 Aug;45(2):163-83; quiz 184-6. doi: 10.1067/mjd.2001.114736.
The panniculitides represent a group of heterogeneous inflammatory diseases that involve the subcutaneous fat. The specific diagnosis of these diseases requires histopathologic study because different panniculitides usually show the same clinical appearance, which consists of subcutaneous erythematous nodules on the lower extremities. However, the histopathologic study of panniculitis is difficult because of an inadequate clinicopathologic correlation, and the changing evolutionary nature of the lesions means that biopsy specimens are often taken from late-stage lesions, which results in nonspecific histopathologic findings. In addition, large-scalpel incisional biopsies are required. However, we believe that by obtaining appropriate biopsy specimens and with adequate clinicopathologic correlation, a specific diagnosis may be rendered in most cases of panniculitis. It must be accepted that all panniculitides are somewhat mixed because the inflammatory infiltrate involves both the septa and lobules; however, in general the differential diagnosis between a mostly septal and a mostly lobular panniculitis is straightforward at scanning magnification. Mostly septal panniculitides with vasculitis include leukocytoclastic vasculitis involving the small blood vessels of the septa; superficial thrombophlebitis resulting from inflammation and subsequent thrombosis of large veins of the septa; and cutaneous polyarteritis nodosa, which is a vasculitis involving arteries and arterioles of the septa of subcutaneous fat with few or no systemic manifestations. Often septal panniculitides with no vasculitis are the consequence of dermal inflammatory processes extending to the subcutaneous fat, such as necrobiosis lipoidica, scleroderma, subcutaneous granuloma annulare, rheumatoid nodule, and necrobiotic xanthogranuloma. However, in other cases, the inflammatory process is primarily located in the fibrous septa of the subcutis with or without involvement of the overlying dermis. The most frequently seen septal panniculitis is erythema nodosum, which, in fully developed lesions, is characterized histopathologically by Miescher's radial granulomas in the septa.
脂膜炎是一组累及皮下脂肪的异质性炎症性疾病。这些疾病的明确诊断需要进行组织病理学研究，因为不同的脂膜炎通常表现出相同的临床外观，即下肢出现皮下红斑结节。然而，由于临床病理相关性不足，脂膜炎的组织病理学研究存在困难，而且病变不断演变的性质意味着活检标本往往取自晚期病变，这导致组织病理学结果缺乏特异性。此外，需要进行大刀切取活检。不过，我们认为，通过获取合适的活检标本并进行充分的临床病理相关性分析，大多数脂膜炎病例都可以做出明确诊断。必须承认，所有脂膜炎都存在一定程度的混合，因为炎症浸润同时累及间隔和小叶；然而，一般来说，在扫描放大倍数下，主要为间隔性脂膜炎和主要为小叶性脂膜炎之间的鉴别诊断并不困难。伴有血管炎的主要为间隔性脂膜炎包括累及间隔小血管的白细胞破碎性血管炎；由间隔大静脉炎症及随后血栓形成导致的浅表血栓性静脉炎；以及皮肤结节性多动脉炎，这是一种累及皮下脂肪间隔动脉和小动脉且很少或没有全身表现的血管炎。通常无血管炎的间隔性脂膜炎是真皮炎症过程扩展至皮下脂肪的结果，如类脂质渐进性坏死、硬皮病、皮下环状肉芽肿、类风湿结节和坏死性黄色肉芽肿。然而，在其他情况下，炎症过程主要位于皮下组织的纤维间隔，可伴有或不伴有上层真皮受累。最常见的间隔性脂膜炎是结节性红斑，在完全发展的病变中，其组织病理学特征为间隔内出现米舍尔氏放射状肉芽肿。
