Department of Pathology, Fudan University Shanghai Cancer Center.
Department of Oncology, Shanghai Medical College, Fudan University, Shanghai.
Am J Surg Pathol. 2021 Jun 1;45(6):765-772. doi: 10.1097/PAS.0000000000001632.
EBV+ inflammatory follicular dendritic cell (FDC) sarcoma is an indolent malignant neoplasm of spindled FDCs with a rich lymphoplasmacytic infiltrate and a consistent association with Epstein-Barr virus (EBV). It occurs exclusively in the liver and spleen, with the exception of a few colonic examples. In this study, we report 9 extrahepatosplenic cases, including 4 occurring in previously undescribed sites, but all apparently anatomically related to the aerodigestive tract. The cases included 5 gastrointestinal tumors all presenting as colonic pedunculated polyps, 2 presenting as mesocolon mass, and 2 involving the palatine or nasopharyngeal tonsils. One patient with a colonic tumor was complicated by paraneoplastic pemphigus. The patients had a median age of 58 years, with female predominance (female:male=7:2). A favorable outcome was observed in 7 patients. Histologically, EBV+ inflammatory FDC sarcomas arising from these anatomic sites were similar to their hepatosplenic counterparts. Spindled to oval neoplastic cells with ill-defined cell borders were dispersed or formed loose whorled fascicles in a dense lymphoplasmacytic background. They had vesicular nuclei with distinct nucleoli and typically exhibited a range of nuclear atypia in the same case. The neoplastic cells showed variable expression of FDC markers and were labeled for Epstein-Barr virus-encoded RNA on in situ hybridization. These 9 cases thus broaden the clinicopathologic scenarios of EBV+ inflammatory FDC sarcoma. Recognition of the potential existence of this tumor type in extrahepatosplenic sites permits a correct diagnosis to be made.
EBV+ 炎症性滤泡树突状细胞（FDC）肉瘤是一种惰性恶性肿瘤，由富淋巴细胞浆细胞浸润的梭形 FDC 组成，与 Epstein-Barr 病毒（EBV）密切相关。它仅发生于肝脏和脾脏，除了少数结肠病例外。本研究报告了 9 例肝脾外的病例，包括 4 例发生在以前未描述的部位，但均与呼吸道和消化道解剖位置有关。这些病例包括 5 例胃肠道肿瘤，均表现为结肠有蒂息肉，2 例表现为结肠系膜肿块，2 例累及腭扁桃体或鼻咽扁桃体。1 例结肠肿瘤患者并发副肿瘤天疱疮。患者的中位年龄为 58 岁，女性居多（女性：男性=7:2）。7 例患者预后良好。从这些解剖部位发生的 EBV+ 炎症性 FDC 肉瘤在组织学上与肝脾相应肿瘤相似。边界不清的梭形至椭圆形肿瘤细胞在致密的淋巴细胞浆细胞背景中呈分散状或形成疏松的漩涡状束。它们具有泡状核，有明显的核仁，在同一病例中通常表现出一定程度的核异型性。肿瘤细胞表达 FDC 标志物的程度不同，原位杂交显示 EBV 编码的 RNA 阳性。这 9 例病例拓宽了 EBV+ 炎症性 FDC 肉瘤的临床病理表现。认识到这种肿瘤类型在肝脾外部位的存在，可以做出正确的诊断。
