Zelger B, Sepp N, Schmid K W, Hintner H, Klein G, Fritsch P O
Department of Dermatology, University of Innsbruck, Austria.
Hum Pathol. 1992 Jun;23(6):668-75. doi: 10.1016/0046-8177(92)90323-u.
Sneddon's syndrome is a potentially fatal arterio-occlusive disorder characterized by generalized livedo racemosa and cerebrovascular lesions. Skin biopsies often fail to yield diagnostic arterial lesions. In the present series, affected vessels were found in skin biopsies from 12 of 15 patients with Sneddon's syndrome. Selection of the correct biopsy site (seemingly uninvolved skin at the center of a livedo racemosa area), adequate biopsy size (1 to 2 cm), and serial sections are essential for the detection of relevant vascular pathology. Only small to medium-sized arteries of the dermis-subcutis boundary were found to be involved. Lesions follow a distinct course. The initial stage displays partial detachment of endothelial cells, adhesion of mononuclear cells interspersed with fibrin ("endothelitis"), a marked edema of the surrounding connective tissue with numerous dilated capillaries, and a predominantly lymphohistiocytic infiltrate with polymorphonuclear leukocytes. In the early phase a sponge-like plug is formed from mononuclear cells, fibrin, and red blood cells, leading to partial to complete obstruction. A perivascular inflammatory infiltrate, devoid of polymorphonuclear leukocytes, is located around affected arteries; in the adventitia of the occluded vessel, a very regular corona of dilated capillaries appears that is continuous with more peripheral dilated and branching vessels. Organization of the occluding plug ensues in the intermediate stage by "subendothelial cell proliferation," most likely due to immigrating smooth muscle cells. In the final stage, the occluding artery undergoes fibrosis, shrinkage, and atrophy.
斯内登综合征是一种潜在致命的动脉闭塞性疾病，其特征为全身性网状青斑和脑血管病变。皮肤活检常常无法发现具有诊断意义的动脉病变。在本系列研究中，15例斯内登综合征患者中有12例的皮肤活检发现了受累血管。选择正确的活检部位（网状青斑区域中心看似未受累的皮肤）、足够的活检大小（1至2厘米）以及连续切片对于发现相关血管病变至关重要。仅发现真皮 - 皮下组织交界处的中小动脉受累。病变呈现出独特的发展过程。初始阶段表现为内皮细胞部分脱离、散在有纤维蛋白（“内皮炎”）的单核细胞黏附、周围结缔组织明显水肿伴大量扩张的毛细血管，以及以淋巴细胞和组织细胞为主并伴有多形核白细胞的浸润。在早期，由单核细胞、纤维蛋白和红细胞形成海绵状栓子，导致部分至完全阻塞。受累动脉周围有血管周围炎性浸润，但无多形核白细胞；在闭塞血管的外膜，出现非常规则的扩张毛细血管晕，与更外周的扩张和分支血管相连。在中间阶段，闭塞栓子通过“内皮下细胞增殖”发生机化，很可能是由于平滑肌细胞迁入所致。在最后阶段，闭塞动脉发生纤维化、收缩和萎缩。
