[Clinicopathologic features and prognosis of inflammatory pseudotumor-like follicular dendritic cell sarcomas in liver and spleen: an analysis of seven cases].

Objective: To investigate the clinicopathological features and prognostic parameters of the inflammatory pseudotumor-like follicular dendritic cell sarcoma (IPT-like FDCS) of liver and spleen. Methods: Ninteen cases of inflammatory pseudotumor (IPT) and 5 cases of IPT-like FDCS of the liver and spleen were collected at the First Affiliated Hospital, Army Medical University from 2006 to 2016. HE sections, immunohistochemical staining, and Epstein-Barr virus encoded nuclear RNA (EBER) in situ hybridization were reviewed along with a summary of the literature. Results: Among the previously diagnosed 19 cases of IPT of the liver and spleen, 2 cases were misdiagnosed (the ratio of 2/19). Among 7 new cases including 3 males and 4 females, 3 cases involved the liver and 4 cases involved the spleen. The age range was 37-64 years (mean 53 years). The maximum tumor diameter ranged from 3.0 to 11.0 cm (mean 6.5 cm). Surgical resections were performed in all patients with follow-up time ranging from 3 to 84 months.All patients were disease-free.7 new cases were all positive for EBER, and showed the expression of at least one of the FDC markers, including CD21, CD23, and CD35. The rest of 17 cases of IPT were all negative for EBER and essentially negative for FDC markers, but were all positive for SMA. Conclusions: IPT-like FDCS of the liver and spleen is a rare low-grade malignant tumor morphologically mimicking inflammatory pseudotumor, and is easy to be misdiagnosis due to under-recognition. EBER in situ hybridization and FDC markers are indispensable for confirming the diagnosis.目的： 探讨肝脏/脾脏炎性假瘤样滤泡树突细胞肉瘤(FDCS)的临床病理特征、诊断及预后相关因素，以加强对该少见肿瘤的认识。 方法： 收集2006至2016年解放军陆军军医大学第一附属医院诊断的19例肝脏/脾脏炎性假瘤和5例炎性假瘤样FDCS，对其进行组织形态观察、免疫组织化学染色和EB病毒原位杂交检测，并结合文献报道的炎性假瘤样FDCS病例进行分析。 结果： 复核19例先前诊断为肝脏/脾脏炎性假瘤的病例，发现其中2例为未被识别的炎性假瘤样FDCS(漏诊比例2/19)。调整后的7例肝脏/脾脏炎性假瘤样FDCS中，发生于肝脏3例，脾脏4例；男性3例，女性4例。患者年龄37～64岁(平均53岁)，肿瘤最大径3.0～11.0 cm(平均6.5 cm)。7例患者均行单纯手术切除治疗，随访时间3～84个月，均无瘤生存。7例炎性假瘤样FDCS EB病毒编码的小RNA(EBER)阳性，并不同程度地表达CD21、CD23、CD35等滤泡树突状细胞标志物；17例炎性假瘤则均显示EBER阴性，平滑肌肌动蛋白阳性，滤泡树突状细胞标志物基本为阴性。 结论： 肝脏/脾脏炎性假瘤样FDCS是一种少见的低度恶性肿瘤，组织形态与炎性假瘤非常相似，对其认识不足时很容易误诊或漏诊，EB病毒及滤泡树突状细胞相关免疫标志物检测对其诊断及鉴别诊断具有重要作用。.