Hudnall S D, Berenson J R
Department of Pathology, UCLA School of Medicine, Jonsson Cancer Center.
Hum Pathol. 1993 Jul;24(7):796-801. doi: 10.1016/0046-8177(93)90018-c.
We describe an unusual case of small lymphocytic lymphoma with multiple prominent pseudofollicular proliferation centers in which immunohistochemistry reveals that the small cells are surface IgM kappa positive and the large pseudofollicular cells are surface IgA kappa positive. We further show by genomic DNA analysis that the tumor tissue contains two JH rearrangements, one Cmu rearrangement, one C alpha rearrangement, and a single C kappa rearrangement, strongly suggesting that the large cells within the proliferation centers have arisen from the small cells via a clonal heavy chain immunoglobulin isotype switch. Isotype switching in human lymphoma and leukemia appears to be an uncommon event. However, there are reports that strongly support isotype switching in pre-B-cell leukemia, Richter's syndrome, lymphoid blast crisis of chronic myelogenous leukemia, and multiple myeloma. To our knowledge, there have been no previous reports demonstrating isotype switching within the proliferation centers of small lymphocytic lymphoma. We present evidence of in vivo intratumoral isotype switching within the proliferation centers of a small lymphocytic lymphoma documented at the level of immunohistochemistry and DNA rearrangement.
我们描述了一例罕见的小淋巴细胞淋巴瘤病例，其具有多个显著的假滤泡增殖中心，免疫组织化学显示小细胞表面IgM κ阳性，而大的假滤泡细胞表面IgA κ阳性。我们通过基因组DNA分析进一步表明，肿瘤组织包含两个JH重排、一个Cμ重排、一个Cα重排和一个单一的Cκ重排，强烈提示增殖中心内的大细胞是由小细胞通过克隆性重链免疫球蛋白同种型转换产生的。人类淋巴瘤和白血病中的同种型转换似乎是一个不常见的事件。然而，有报告有力地支持了前B细胞白血病、里氏综合征、慢性粒细胞白血病的淋巴细胞母细胞危象和多发性骨髓瘤中的同种型转换。据我们所知，以前没有关于小淋巴细胞淋巴瘤增殖中心内同种型转换的报道。我们提供了在免疫组织化学和DNA重排水平记录的小淋巴细胞淋巴瘤增殖中心内体内肿瘤内同种型转换的证据。
