脾脏B细胞边缘区淋巴瘤侵犯骨髓的病理学特点与鉴别诊断

Clinicopathologic features and differential diagnosis of splenic B-cell marginal zone lymphomainvolving bone marrow

目的探讨脾脏B细胞边缘区淋巴瘤（SMZL）侵犯骨髓的病理学特点与鉴别诊断。方法回顾性分析了22例SMZL侵犯骨髓患者的临床病理档案资料，并行骨髓活检标本的形态学及免疫组织化学EliVision法染色检查。其中18例行全血细胞计数以及外周血涂片、骨髓穿刺涂片和流式细胞学检查。结果18例患者中11例外周血涂片可见绒毛淋巴细胞；骨髓涂片15例淋巴细胞比例增高（〉20．0％）；6例可见绒毛淋巴细胞。18例患者的流式细胞学检测（FCM）结果显示18例为CD19^＋CD20^＋FMC7^＋CD22^＋CD10-CD2-CD3-CD7-。22例患者的骨髓活检切片示22例（100％）出现骨髓侵犯，4例（18．2％）轻度侵犯，11例（50．0％）中度侵犯，7例（31．8％）为重度侵犯。分布方式：16例（72．7％）血窦内分布，14例（63．6％）为间质型分布，11例（50．0％）为灶性分布，1例（4．5％）为弥漫型分布；2例（9．1％）可见反应性生发中心，CD23染色示滤泡树突状细胞网阳性，bcl-2染色示生发中心阴性。22例免疫组织化学染色结果示瘤细胞抗原表达均为CD20^＋PAX5^＋CD3-CD5-CD10-cyclin D1-CD23-CD43-AnnexinA1-CDllC-CD25-。2例（9．1％）CD38^＋，2例（9．1％）CD138^＋。结论SMZL侵犯骨髓具有多种侵犯方式，单纯窦内型罕见，免疫表型缺乏特征性，需要与多种小B细胞淋巴瘤鉴别。

Objective To study the clinicopathologic features and differential diagnosis of splenic B-cell marginal zone lymphoma （SMZL） involving bone marrow. Methods The clinical and pathologic features of 22 patients with SMZL were retrospectively studied. Immunophenotypic analysis was carried out by flow cytometry and immunohistochemistry. Immunoglobulin heavy chain rearrangement study was performed using polymerase chain reaction-based method. Results Villous lymphocytes were found in peripheral blood smears of 11/18 of the patients. In bone marrow aspirates, lymphocytosis （ 〉 20% ） was demonstrated in 15 cases （15/18） and villous lymphocytes in 6 cases （6/18）. Flow cytometry showed CD19＋ CD20＋ FMC7＋ CD22＋ CD10- CD2- CD3- CD7- in 18 cases. Bone marrow biopsies of all the22 patients revealed various degrees and patterns of neoplastic infiltration, as follows： mild （4 cases, 18.2% ） , moderate （11 cases, 50.0%） or severe （7 cases, 31.8%）; intrasinusoidal （16 cases, 72.7%）, interstitial （ 14 cases, 63.6% ）, nodular （ 11 cases, 50. 0% ） or diffuse （ 1 case, 4. 5% ） . Reactive germinal center formation （ CD23＋ bcl-2 - ） was found in 2 cases （ 91.0% ）. Immunohistochemical study showed the following results： CD20＋ PAX5＋CD3- CD5- CD10- cyclin D1- CD23- CD43- Annexin A1- CDllC- CD25- in all the 22 cases, CD38＋ in 2 cases （9. 1%） and CD138＋ in 2 cases （9. 1%）. Conclusions Different and overlapping patterns of bone marrow involvement are observed in SMZL. As the histologic and immunophenotypic features are not specific to SMZL, distinction from other types of mature B-cell lymphomas is necessary.