Gong Qi-Xing, Fan Qin-He, Zhou Zhi-Shao, Zhang Zhi-Hong, Yu Mei-Ning, Wang Zhen, Wang Cong, Zhang Wei-Ming
Department of Pathology, First Affiliated Hospital, Nanjing Medical University, Nanjing 210029, China.
Zhonghua Bing Li Xue Za Zhi. 2008 Jan;37(1):40-4.
To study the clinicopathologic features of inflammatory pseudotumor-like follicular dendritic cell tumor of spleen.
One case of inflammatory pseudotumor-like follicular dendritic cell tumor of spleen was examined macroscopically and microscopically. Immunohistochemical study for CD21, CD23, CD35, clusterin, S-100 protein, vimentin, smooth muscle actin, CD1a, CD68, ALK protein, CD30, CD31, CD34, CD3 and CD20 was performed on formalin-fixed, paraffin-embedded sections by standard EnVision method. In-situ hybridization for Epstein-Barr virus (EBV)-encoded RNA was also carried out.
Macroscopically, inflammatory pseudotumor-like follicular dendritic cell tumor was large in size, tan-colored, soft to rubbery in consistance and associated with central hemorrhage and necrosis. Histological examination showed scattered follicular dendritic cells admixed with abundant lymphocytes and plasma cells in the background, simulating inflammatory pseudotumor. On high-power magnification, the follicular dendritic cells possessed a moderate amount of pale to lightly eosinophilic cytoplasm, with indistinct cell borders. The nuclei were ovoid or spindly, with vesicular or stippled chromatin and small distinct, often centrally located, nucleoli. Some of the tumor cells showed nuclear pleomorphism and contained irregular foldings of nuclear membrane, coarse chromatin and prominent eosinophilic nucleoli. Mitotic figures were rarely identified. Immunohistochemical study showed that the tumor cells were positive for vimentin, clusterin, smooth muscle actin and CD68. They were weakly and focally positive for CD35 and S-100 protein, but negative for CD21, CD23, CD1a, ALK protein, CD30, CD31 and CD34. Most of the background lymphocytes were of T-lineage (CD3-positive) ,some were CD20 (B-cell marker)-positive. EBV RNA was demonstrated in the tumor cells by in-situ hybridization analysis.
Inflammatory pseudotumor-like follicular dendritic cell tumor is a rarely encountered low-grade malignancy with distinctive morphologic pattern. It is associated with EBV infection.
研究脾脏炎性假瘤样滤泡树突状细胞肿瘤的临床病理特征。
对1例脾脏炎性假瘤样滤泡树突状细胞肿瘤进行大体及显微镜检查。采用标准的EnVision法对福尔马林固定、石蜡包埋切片进行CD21、CD23、CD35、clusterin、S-100蛋白、波形蛋白、平滑肌肌动蛋白、CD1a、CD68、间变性淋巴瘤激酶（ALK）蛋白、CD30、CD31、CD34、CD3和CD20的免疫组化研究。还进行了爱泼斯坦-巴尔病毒（EBV）编码RNA的原位杂交。
大体上，炎性假瘤样滤泡树突状细胞肿瘤体积较大，呈棕褐色，质地软至橡皮样，伴有中央出血和坏死。组织学检查显示，背景中有散在的滤泡树突状细胞，混有大量淋巴细胞和浆细胞，类似炎性假瘤。高倍镜下，滤泡树突状细胞有中等量淡至轻度嗜酸性细胞质，细胞边界不清。细胞核呈卵圆形或梭形，有泡状或点彩状染色质，小而明显，常位于中央的核仁。部分肿瘤细胞显示核多形性，核膜有不规则折叠、粗染色质和明显的嗜酸性核仁。很少见到有丝分裂象。免疫组化研究显示，肿瘤细胞波形蛋白、clusterin、平滑肌肌动蛋白和CD68呈阳性。它们CD35和S-100蛋白呈弱阳性且局灶阳性，但CD21、CD23、CD1a、ALK蛋白、CD30、CD31和CD34呈阴性。大多数背景淋巴细胞为T细胞系（CD3阳性），部分为CD20（B细胞标志物）阳性。原位杂交分析在肿瘤细胞中检测到EBV RNA。
炎性假瘤样滤泡树突状细胞肿瘤是一种罕见的低级别恶性肿瘤，具有独特的形态学模式。它与EBV感染有关。
