Yamakawa M, Ikeda I, Masuda A, Enomoto H, Ando A, Kasajima T
Second Department of Pathology, School of Medicine, Tokyo Women's Medical University, Japan.
Am J Surg Pathol. 1999 May;23(5):536-45. doi: 10.1097/00000478-199905000-00007.
Follicular lesions include germinal center (GC) hyperplasia, regressive transformation of GCs, and follicle lysis. The present histologic, electron microscopic, and immunohistochemical study of six autopsy cases after organ transplantation accompanied by the administration of immunosuppressive drugs revealed a peculiar regression of lymph node GCs in two cases, which has not been noted previously. The histologic findings of the regressive GCs were classified into three patterns. In pattern A, the GCs had few or no lymphocytes and were surrounded by a poorly developed mantle zone-like structure. Apoptotic cell death of GC lymphocytes was found in a few GCs, but most GCs lacked tingible body macrophages. In pattern B, the GC lymphocytes and tingible body macrophages were absent, showing crowded follicular dendritic cells (FDCs) in a corpuscular shape. In pattern C, the lymphocytic mantle was absent. The GCs were smaller than those in the other patterns, and the shape was irregular because of disintegration of FDCs. The immunostaining for FDC markers revealed dispersed growth of FDCs. On electron microscopy, the lesions were composed of a dense mass of elliptical and oval cells without prominent cytoplasmic processes, a labyrinthlike structure, and emperipolesis of lymphocytes. The distinct desmosomelike adhesive junctions, specific electron microscopic features of FDCs, were evident. We propose to call these follicular lesions "FDC-only lymphoid follicles." It is speculated that this follicle may be evoked after preceding follicular hyperplasia with a complicated mechanism including increased apoptosis of GC lymphocytes and decreased lymphocyte migration to lymph node GCs caused by immunosuppressive drugs.
滤泡性病变包括生发中心（GC）增生、生发中心的退行性转化和滤泡溶解。目前对6例器官移植后尸检病例进行的组织学、电子显微镜和免疫组织化学研究，这些病例均使用了免疫抑制药物，结果发现其中2例淋巴结生发中心出现了一种特殊的退行性变，这在以前尚未被注意到。退行性生发中心的组织学表现分为三种类型。在A型中，生发中心淋巴细胞很少或没有，周围是发育不良的套区样结构。在少数生发中心发现了生发中心淋巴细胞的凋亡性细胞死亡，但大多数生发中心缺乏吞噬细胞。在B型中，生发中心淋巴细胞和吞噬细胞缺失，可见密集的球状滤泡树突状细胞（FDC）。在C型中，淋巴细胞套缺失。生发中心比其他类型的小，由于滤泡树突状细胞解体，其形状不规则。滤泡树突状细胞标志物的免疫染色显示滤泡树突状细胞呈分散生长。电子显微镜下，病变由密集的椭圆形和卵圆形细胞组成，如果突出的细胞质突起，有迷宫样结构，并有淋巴细胞的入胞作用。明显可见独特的桥粒样黏附连接，这是滤泡树突状细胞的特异性电子显微镜特征。我们建议将这些滤泡性病变称为“仅滤泡树突状细胞的淋巴滤泡”。推测这种滤泡可能是在先前滤泡增生后诱发的，其机制复杂，包括生发中心淋巴细胞凋亡增加以及免疫抑制药物导致淋巴细胞向淋巴结生发中心迁移减少。
