淋巴结纤维母细胞性网状细胞肿瘤2例临床病理分析

Fibroblastic reticular cell tumor:a clinical and pathologic analysis of 2 cases

目的分析纤维母细胞性网状细胞肿瘤(fibroblastic reticular cell tumour,FRCT)的临床病理学特征。方法回顾性分析2例淋巴结FRCT的临床病理资料,并复习相关文献。结果 2例患者均行肿大淋巴结活检术。镜检:淋巴结结构破坏,大量梭形细胞增生,呈结节状或膨胀性生长。梭形细胞呈席纹状排列,瘤细胞之间常穿插纤细的胶原纤维,并可见大量炎性细胞浸润。梭形细胞较肥胖,细胞边界不清,空泡状核,核膜薄且有褶皱,核仁明显,核分裂可见。免疫表型:例1瘤细胞actin、SMA和CD68均阳性,S-100弱阳性,CD30、PAX-5、ALK、desmin、CK(AE1/AE3)、CD21、CD35、CD23和CD1a均阴性,EBER原位杂交检测阴性;例2瘤细胞CK(AE1/AE3)、desmin、CD68和SMA均阳性,CD21、CD35、CD23和CD1a均阴性,EBER原位杂交检测阳性。结论 FRCT是一种罕见的肿瘤,多发生于淋巴结,可分为CK阳性和CK阴性两类,其诊断主要依赖于病理学形态和免疫表型,例2EBER原位杂交检测阳性,提示FRCT的发生可能与EBV感染有关。

Purpose To analyze the clinical and pathological characteristics of fibroblastic reticular cell tumor （FRCT）. Methods Two cases of FRCT involving the lymph nodes were collected, their clinical and pathological features investigated with review of the re- lated literatures. Results The enlarged lymph nodes in both patients were removed and presented for pathologic examination. Micro- scopically, the normal lymph node structure was destructed, replaced by spindle cells with nodular or swelling growth pattern. The spindle cells were arranged in storiform, interspersed with fine collagen. The tumor cells were plump, with unclear boundary. The nu- clei were vesicular, with irregular folded thin nuclear membrane, and obvious nucleolus. The mitoses were remarkable. A large number of inflammatory cells infiltrated in the stroma. As for the immunohistochemical staining, tumor ceils in case one were positive for actin, SMA, CD68, weakly positive for S-100, and negative for CD30, PAX-5, ALK, desmin, CK（AE1/AE3）, CD21, CD35, CD23 as well as CDla. Tumor cells were negative for EBV-ISH detection. Tumor cells in case two were positive for CK （AE1/AE3）, desmin, CD68 and SMA, but negative for CD21, CD35, CD23, and CDla, whereas positive for EBER. Conclusion FRCT is a rare tumor, commonly involved the lymph nodes. It can be divided into two categories according to the expression of CK. Its diagnosis mainly de- pends on the comprehensive analysis of pathological morphology and immunohistochemistry. One case in our study shows EBER positiv- ity, indicating that tumor might be associated with EBV infection, which is worthy to be further investigated.