纵隔芯针活检的病理诊断

Pathologic diagnoses of core needle biopsies of the mediastinum

目的 提高纵隔芯针穿刺组织的诊断准确性并做出具体分类。方法 用光镜、免疫组织化学抗生物素蛋白-生物素复合物法(ABC法)回顾性观察65例纵隔穿刺组织的形态和免疫组织化学表型,利用聚合酶链反应(PCR)检测部分非霍奇金淋巴瘤的基因重排状况,并随访。结果 本组标本镜下主要由不同比例的上皮样细胞、淋巴样细胞和纤维组织组成,包括21例淋巴瘤、20例肺癌、14例胸腺瘤、4例胸腺癌、3例精原细胞瘤、1例慢性炎症。2例因穿刺组织过少,无法诊断。本组淋巴瘤依不同类型可表达CD20、CD3、末端脱氧核苷酸转移酶(TDT)、CD30、D15或上皮膜抗原(EMA);除3例肺小细胞癌细胞角蛋白(CK)阴性外,17例肺癌均表达CK;10例肺和1例胸腺小细胞癌突触素、嗜铬粒素A(CgA)、神经元特异性烯醇化酶(NSE)均阳性,CD5阴性;3例肺腺癌甲状腺转录因子阳性,CD5阴性;14例胸腺瘤CK、CD3或CD20可阳性;3例胸腺癌表达CK和CD5;3例精原细胞瘤胎盘碱性磷酸酶阳性、CK阴性。5例淋巴母细胞性淋巴瘤T细胞型的T细胞受体β链的编码基因存在重排,3例大B细胞淋巴瘤和1例大细胞间变B细胞淋巴瘤存在免疫球蛋白重链编码基因的重排。结论 纵隔穿刺组织的镜下诊断需结合临床和影像资料,选择适当的免疫组织化学套餐,才能提高确诊率。

Objectives To assess the diagnostic accuracy and to study the histologic typing of mediastinal lesions using core needle biopsies. Methods The histopathology and immunophenotype of 65 mediastinal core needle biopsy specimens were studied retrospectively by light microscopy and immunohistochemical staining (ABC method). Gene rearrangement studies were performed in some of the non-Hodgkin' s lymphomas cases using PCR. Follow-up records were also analyzed. Results Morphologically, all specimens showed a combination of epithelioid cells, lymphoid cells and fibrous tissue in different proportions. The pathologic diagnoses included lymphoma (21 cases) , pulmonary carcinoma (20 cases) , thymoma (14 cases) , thymic carcinoma (4 cases) , seminoma (3 cases) and chronic inflammation (1 case). Definitive diagnosis was not possible in 2 cases due to insufficient material. The tumor cells in lymphoma (21 cases) expressed CD20, CDS, TDT, CD30, CD15 or EMA, depending on their histologic subtypes. Tumor cells in the 17 pulmonary carcinoma cases expressed cytokeratin(CK) , except 3 cases of small cell carcinoma of lung. Synaptophysin, chromogranin A and neuron-specific enolase were all positive in the 10 cases of small cell carcinoma of lung and 1 case of thymic small cell carcinoma (which was also CD5 negative) . The 3 cases of adenocarcinoma of lung showed positivity for thyroid transcription factor-1 (TTF-1) and they were negative for CD5. The 14 thymoma cases expressed CK,CD3 or CD20. The 3 thymic carcinoma cases expressed CK and CD5. Placental-like alkaline phosphatase (PLAP) was positive in 3 seminoma cases which were CK-negative. Immunoglobulin heavy chain gene was rearranged in the 3 cases of diffuse large B-cell lymphoma and 1 B-cell anaplastic large cell lymphoma case. T-cell receptor β gene was rearranged in 5 T-cell lymphoblastic lymphoma cases. Conclusions Microscopic assessment of tissue samples from mediastinal core needle biopsies should be made in combination with clinical and radiologic information. Ancillary investigations, including immunohistochemical staining and/or gene rearrangement studie, are needed in both non-lymphoma and lymphoma cases of mediastinum.