肺黏膜相关淋巴组织型淋巴瘤的表型和IgH基因重排的检测价值

目的探讨肺黏膜相关淋巴组织型淋巴瘤（MALTLoma）的免疫表型和免疫球蛋白重链（IgH）基因重排检测的意义。方法对12例肺MALTLoma患者的临床病理资料进行回顾性分析和免疫组化研究，7例进行IgH和T细胞受体γ链（TCRγ）基因重排检测，并对治疗后结果随访。结果12例中，开胸肺活检7例，经电视胸腔镜肺活检2例，细针肺穿刺活检3例。病理组织检查结果：瘤细胞主要由中心细胞样淋巴细胞、小淋巴细胞样瘤细胞组成；12例有淋巴上皮病变，11例有反应性淋巴滤泡，10例有淋巴滤泡的克隆化，9例有血管受侵，4例有胸膜受侵；瘤细胞表达B细胞相关抗原。7例行IgH基因重排检测，FR2阳性6例，FR3A阳性5例。TCRγ1和TCRγ2基因重排检测均为阴性。12例患者单纯化疗3例，手术切除8例，其中术后化疗6例，对症治疗1例；随访11例，随访时间1—12年，复发1例，死亡2例。结论组织病理学结合免疫组化检查能对大多数具有典型病变的肺MALTLoma进行诊断；在肺MALTLoma与肺良性淋巴组织增生性疾病的鉴别诊断上，IgH基因重排检测有重要的辅助价值。

The value of detection of gene rearrangement of immunoglobulin heavy chain and immunohistochemistry in pulmonary mucosa-associated lymphoid tissue type lymphoma

OBJECTIVE: To investigate the features of gene rearrangement of immunoglobulin heavy chain (IgH) and immunophenotypes of pulmonary mucosa-associated lymphoid tissue type lymphoma (MALTLoma). METHODS: The clinical and pathological data of 12 cases with pulmonary MALTLoma and follow-up information were retrospectively reviewed, and the paraffin-embedded samples were examined with immunohistochemistry staining (12 cases) and semi-nested polymerase chain reaction (PCR) for IgH and T-cell receptor gamma (TCRgamma) gene rearrangement (7 cases). RESULTS: The patients included 9 cases confirmed by open or video-assisted thoracoscopic lung biopsy and 3 cases by needle lung biopsy. Histopathologically, the tumors were composed of a spectrum of cell types that included mainly centrocyte-like cells and small lymphocytes. Lymphoepithelial lesions were identified in 12 cases, reactive folliculus lymphaticus in 11 cases, follicular colonization in 10 cases, vascular infiltration in 9 cases, and pleura involvement in 4 cases. All cases showed immunoreactivity for B-cell correlative markers. Positivity for FR2 and FR3A primers in MALTLoma were found in 6 case and 5 case respectively. The detection of TCRgamma1 and TCRgamma2 was negative in 7 cases. The combined positive rate was 100%. Chemotherapy alone was administered in 3 patients, surgery alone was performed in 8 patients, and chemotherapy after operation was carried out in 6 patients. Follow-up data were available in 11 patients. Eight of them were alive and stable, one experienced relapse and two died of the disease within 11 years and 12 years after diagnosis respectively. CONCLUSIONS: Most of the cases of pulmonary MALTLoma can be diagnosed with morphology and immunohistochemistry staining if the lesions are typical. PCR detection of IgH gene rearrangement would be helpful in differential diagnosis from benign lymphoplasia of the lung.