Kaposiform lymphangiomatosis is an uncommon generalized lymphatic anomaly with distinctive clinical, radiologic, histopathologic, and molecular findings. Herein, we document the pathology in 43 patients evaluated by the Boston Children’s Hospital Vascular Anomalies Center from 1999 to 2020. The most frequent presentations were respiratory difficulty, hemostatic abnormalities, and a soft tissue mass. Imaging commonly revealed involvement of some combination of mediastinal, pulmonary, pleural, and pericardial compartments and most often included spleen and skeleton. Histopathology was characterized by dilated, redundant, and abnormally configured lymphatic channels typically accompanied by dispersed clusters of variably canalized, and often hemosiderotic, spindled lymphatic endothelial cells that were immunopositive for D2-40, PROX1, and CD31. An activating lesional NRAS variant was documented in 9 of 10 patients. The clinical course was typically aggressive, marked by hemorrhage, thrombocytopenia, diminished fibrinogen levels, and a mortality rate of 21%.

卡波西样淋巴管瘤病是一种罕见的全身性淋巴管异常，具有独特的临床、放射学、组织病理学和分子发现。在此，我们记录了 1999 年至 2020 年波士顿儿童医院血管异常中心评估的 43 名患者的病理情况。最常见的症状是呼吸困难、止血异常和软组织肿块。影像学检查通常显示纵隔、肺、胸膜和心包室的某些组合受累，最常见的是脾脏和骨骼。组织病理学的特征是扩张、多余和异常构造的淋巴管，通常伴有分散的不同管化的、通常含铁血黄素的梭形淋巴管内皮细胞簇，这些细胞对 D2-40、PROX1 和 CD31 呈免疫阳性。10 名患者中有 9 名记录了激活性病变NRAS变异。临床病程通常呈侵袭性，表现为出血、血小板减少、纤维蛋白原水平降低，死亡率为 21%。