粒细胞肉瘤的诊断与鉴别诊断

目的 探讨粒细胞肉瘤(granulocytic sarcoma,GS)的诊断与鉴别诊断。方法 对12例GS的组织形态学及免疫表型特征进行研究，并结合外周血、骨髓涂片检查及骨髓活检对全部病例进行FAB分型诊断。结果 12例患者均以淋巴结肿大、结外骨及软组织肿块为首发症状。组织学上瘤细胞核呈圆形、卵圆形或不规则形，胞浆少，核分裂易见，呈弥漫分布。骨髓活检示11例有幼稚细胞弥漫单一性增生，形态与髓外浸润的瘤组织相似。1例没有白血病的形态学改变。免疫组化显示瘤细胞表达CD45 100％阳性、溶菌酶100％阳性、MPO 92％阳性、CD68 83％阳性、CD34 42％阳性、TdT 17％阳性。CD15和Mac387仅表达在分化较成熟的粒细胞。CD3、CD45RA，、CD20、CD45RA、CD79A及CD30阴性。结合 外周血及骨髓涂片检查结果确诊1例为孤立性粒细胞肉瘤(非白血病性粒细胞肉瘤)，11例为急性髓系白血病髓外浸润(白血病性粒细胞肉瘤)，11例中1例为AML-Mo，2例为AML-M1，8例为AML-M2。结论 GS在石蜡切片上因其形态学与非霍奇金淋巴瘤极其相似而容易造成误诊，免疫表型及全面的临床检查，特别是外周血、骨髓涂片检查及骨髓活检对明确诊断有很大帮助。

Diagnosis and differential diagnosis of granulocytic sarcomas

Objective To investigate the diagnosis and differential diagnosis of granulocytic sarcoma(GS). Methods The morphological and immunological characteristics of 12 cases of GS were studied. FAB classification was made by peripheral blood,bone marrow picture and bone marrow biopsy assay. Results All of the 12 cases presented with lymphadenopathy and soft tissue mass. Histologically, the tissue infiltration of GS was composed of blastic cells with round to oval nuclei showing an even, pale chromatin pattern. Some with cleaved or notched nuclei. There were prominent nucleoli and scant cytoplasm in the cells and mitosis was easily found. Immunohistochemically, CD_ 45 and lysozyme were positive in all of the cases, MPO in 11 (92%), CD_ 68 in 10 (83%), CD_ 34 in 5 (42%), and TdT in 2 cases (17%). CD_ 15 and Mac387 were mainly expressed in mature granulocytes. Examination of bone marrow sections and marrow aspirate smears showed that out of the 11 cases tested 8 were AML-M_2, 2 AML-M_1 and 1 AML-M_0. Only 1 case was nonleukemic, ie. solitary granulocytic sarcoma. Conclusion Granulocytic sarcomas are difficult to identify in routine paraffin-embedded tissue sections and usually misdiagnosed as non-Hodgkin's lymphomas. Immunohistochemistry study with a panel of antibodies in combination with bone marrow and peripheral blood examination are helphful in identification of granulocytic sarcoma.