急性非充脂性播散性网织内皮细胞增生症(Letterer-Siwe,勒、雪氏病)是原因未明的进行性致死性疾病。以全身广泛性的网织内皮细胞增生为病变基础。Siwe 氏报告本病之临床病理特征为:(1)肝脾肿大。(2)出血(瘀斑和紫癜)素质。(3)普遍性的轻度淋巴结肿大。(4)进行性贫血,白细胞计数正常。(5)在发生上是非遗传性的。(6)容易被 X 线所显示之骨“肿瘤”。(7)网织内皮细胞普遍增生,在脾、肝、淋巴结、胸腺、皮肤和骨髓内形成灶性肿瘤 Acute non-adipose-disseminated reticuloendothelial disease (Letterer-Siwe, leukemia) is a unexplained progressive fatal disease. Extensive reticular endothelial cell proliferation as the basis for the disease. Siwe’s report of the clinical and pathological features of the disease as follows: (1) hepatosplenomegaly. (2) bleeding (ecchymosis and purpura) quality. (3) The prevalence of mild lymphadenopathy. (4) progressive anemia, normal white blood cell count. (5) Occurs non-genetically. (6) Easily be seen by the X-ray bone “tumor.” (7) reticuloendothelial proliferation, in the spleen, liver, lymph nodes, thymus, skin and bone marrow to form focal tumors