Medina Edward A, Fuehrer Neil E, Miller Frank R, Kinney Marsha C, Higgins Russell A
Department of Pathology, University of Texas Health Science Center, San Antonio, TX, USA.
Department Otolaryngology-Head & Neck Surgery, University of Texas Health Science Center, San Antonio, TX, USA.
Pathol Int. 2016 Sep;66(9):535-9. doi: 10.1111/pin.12446.
Follicular dendritic cell (FDC) proliferations and dysplastic FDCs can be seen in Hyaline-vascular Castleman disease (HVCD). The association between HVCD and FDC sarcoma is well-documented; dysplastic FDCs may be precursors to FDC sarcoma. Herein, we describe a case of HVCD with strikingly large and dysplastic FDCs, which raised the differential of Hodgkin lymphoma and other neoplasms. Scattered dysplastic FDCs were predominantly in germinal centers and mantle zones, and rarely in interfollicular areas. Although occasional germinal centers contained increased FDCs, no mass forming proliferations were present to suggest FDC sarcoma. Immunostaining demonstrated that the atypical FDCs expressed CD21, clusterin and CXCL13, but not CD23, S100, pankeratin or CD30; they aberrantly expressed epidermal growth factor receptor (EGFR). The present case demonstrates that dysplastic FDCs may be present as isolated cells that require immunophenotyping to distinguish them from malignant entities with similar morphologic features. A variety of FDC markers is required to confirm their origin as the expression of any single marker is not assured, as occurred in this case. Pathologists need be aware of FDC proliferations in HVCD because of their association with FDC sarcoma. Aberrant EGFR expression by dysplastic FDCs may indicate that they are pre-neoplastic and necessitate long-term patient follow-up.
在透明血管型Castleman病（HVCD）中可见滤泡树突状细胞（FDC）增殖和发育异常的FDC。HVCD与FDC肉瘤之间的关联已有充分记录；发育异常的FDC可能是FDC肉瘤的前体。在此，我们描述了一例HVCD病例，其中存在显著增大且发育异常的FDC，这增加了霍奇金淋巴瘤和其他肿瘤的鉴别诊断难度。散在的发育异常FDC主要位于生发中心和套区，很少见于滤泡间区域。尽管偶尔生发中心含有增多的FDC，但未发现形成肿块的增殖情况提示FDC肉瘤。免疫染色显示，非典型FDC表达CD21、簇集素和CXCL13，但不表达CD23、S100、全角蛋白或CD30；它们异常表达表皮生长因子受体（EGFR）。本病例表明，发育异常的FDC可能以孤立细胞形式存在，需要进行免疫表型分析以将它们与具有相似形态特征的恶性实体区分开来。由于任何单一标志物的表达都不能确定，因此需要多种FDC标志物来确认它们的来源，本病例就是如此。病理学家需要注意HVCD中的FDC增殖，因为它们与FDC肉瘤有关。发育异常的FDC异常表达EGFR可能表明它们是肿瘤前状态，需要对患者进行长期随访。
