表达间变性淋巴瘤激酶蛋白的弥漫性大B细胞淋巴瘤的临床病理和免疫表型观察

目的探讨表达间变性淋巴瘤激酶（ALK）蛋白的弥漫性大B细胞淋巴瘤（DLBCL）的临床病理特点。方法根据2001年版WHO淋巴造血组织肿瘤分类收集945例DLBCL,以LSAB法作ALK-11染色。对阳性病例再用EnVision法作ALK-11染色,仅EnVision法阳性病例为最终纳入病例。对纳入病例标本用LSAB法加做CD20、CD3、CD30、上皮细胞膜抗原（EMA）、粒酶B、T细胞胞质内抗原（TIA）-1和浆细胞（PC）抗体等免疫表型检测,进行IgH基因重排检测并收集随访资料。结果945例弥漫性大B细胞淋巴瘤中仅5例表达ALK蛋白。4例男性,1例女性,年龄34—72岁,全部原发于淋巴结。临床分期Ⅰ期1例、Ⅱ期2例、Ⅲ期2例。5例随访最长32个月,最短4个月。随访截止时死亡4例,死亡病例最长存活时间32个月。表达ALK蛋白的DLBCL包括中心母细胞性2例、免疫母细胞性1例、间变性1例、浆母细胞性1例;2例中心母细胞性、1例免疫母细胞性和1例间变性均表达CD20。浆母细胞性表达K轻链而不表达CD20。5例均检测到IgH基因重排。ALK蛋白表达：在CD20阳性4例中,1例免疫母细胞性为胞膜和胞质阳性,2例中心母细胞性和1例间变性为胞质颗粒状阳性;1例浆母细胞性为胞核和胞质弥漫阳性。结论ALK蛋白阳性表达DLBLC是一种罕见的,临床过程具侵袭性且预后较差的淋巴瘤,可见于浆母细胞性、中心母细胞性、免疫母细胞性和间变性的大B细胞淋巴瘤。发现1例ALK蛋白表达于胞膜和胞质。

Diffuse large B-cell lymphoma with expression of anaplastic lymphoma kinase protein: clinicopathologic and immunohistochemical study of 5 cases

OBJECTIVE: To study the clinicopathologic features of diffuse large B-cell lymphoma (DLBCL) with expression of anaplastic lymphoma kinase (ALK) protein. METHODS: Nine hundred and forty-five (945) cases of DLBCL (including 177 consultation cases) diagnosed according to the 2001 World Health Organization classification of tumors of hematopoietic and lymphoid tissues were enrolled into the study. Immunohistochemical study for anti-ALK-11 was performed using LSAB technique. The ALK-positive cases were further confirmed by immunohistochemical study using EnVision technique. Only ALK-positive cases by EnVision technique were further analyzed by immunostaining for antigens including CD20, CD3, CD30, EMA, granzyme-B, TIA-1 and PC. Immunoglobulin heavy chain gene rearrangement study was also performed and follow-up data collected. RESULTS: There were altogether 5 (4 males and 1 female) cases of DLBCL showing expression of ALK protein. The age of the patients ranged from 34 to 72 years. All were primary nodal DLBCL. One case belonged to clinical stage I, 2 in stage II and 2 in stage III. The duration of follow up ranged from 4 to 32 months. Three patients subsequently died and the longest survival was 32 months. Morphologic subtypes included centroblastic 2, anaplastic 1, immunoblastic with plasmacytoid differentiation 1 and plasmablastic 1. Immunohistochemically, 4 cases were CD20 positive (including 2 centroblastic, 1 anaplastic and 1 immunoblastic cases). The plasmablastic case expressed kappa light chain and was negative for CD20. Rearrangement of immunoglobulin heavy chain gene was demonstrated in all 5 cases studied. As for ALK protein staining, a mixed membranous and cytoplasmic (1 immunoblastic case), granular cytoplasmic (2 centroblastic and 1 anaplastic cases) and mixed nuclear and cytoplasmic (1 plasmablastic case) patterns were observed. CONCLUSIONS: Expression of ALK protein is a rare phenomenon in DLBCL and can be seen in centroblastic, anaplastic, immunoblastic and plasmablastic subtypes. It is often associated with aggressive clinical behavior and worse prognosis. A new pattern of ALK protein expression, mixed membranous and cytoplasmic, is reported.