Ritter J H, Wick M R, Adesokan P N, Fitzgibbon J F, Zhu X, Humphrey P A
Lauren V. Ackerman Laboratory of Surgical Pathology, Washington University School of Medicine, St Louis, Missouri, USA.
Am J Clin Pathol. 1997 Jul;108(1):60-8.
Determination of the biologic potential of cutaneous lymphoid infiltrates may be difficult by standard histologic or immunohistologic examination. The polymerase chain reaction (PCR) has been used to document clonal rearrangements of the immunoglobulin heavy chain gene in paraffin-embedded fixed tissues. To explore the value of PCR in evaluation of cutaneous lymphoid infiltrates, 93 archival nonmycotic lymphoid lesions (28 small or mixed lymphocytic lymphomas, 15 large cell lymphomas, 40 benign infiltrates, and 10 with atypical features) were analyzed. These cases had been previously immunophenotyped on paraffin sections, and clinical follow-up from 7 to 20 years was gathered. DNA products were generated using a seminested PCR technique, separated by 5% polyacrylamide gel electrophoresis, stained with ethidium bromide, and visualized under UV light. Cases with a 100- to 120-base pair band were scored as positive. Of the 28 small or mixed cell lymphomas, 23 had a B-cell immunophenotype or consisted of a mixture of B and T cells; of these, seven (30%) demonstrated a monoclonal pattern, and three (13%) were indeterminate. Twelve large cell cases were B-cell or mixed; five (42%) of these were positive for a monoclonal band, while four (33%) were indeterminate. None of five T-cell small cell or three T-cell large cell lymphomas demonstrated a monoclonal band. In contrast, 39 of the 40 benign cases were T-cell predominant or mixed lesions. Nevertheless, 18 of these 40 cases on initial testing suggested possible monoclonality. Six were indeterminate, and 12 demonstrated apparent monoclonal bands, of which four were reproducible on repeat testing. No histologic or clinical features of lymphoma were present in 17 of these 18 cases, suggesting that they represent false-positive results. Most of the latter lesions showed sparse perivascular infiltrates, with very few B cells. This suggests that amplification of the immunoglobulin heavy chain gene from a small number of lymphocytes may produce a monoclonal band. In summary, PCR may provide adjunct information about clonality in selected lymphoid skin lesions, but is rather insensitive in this setting. Such data must be carefully considered in the context of the histologic, immunohistologic, and clinical findings, particularly when assessing sparse infiltrates, because of the potential for false-positive results.
通过标准组织学或免疫组织学检查来确定皮肤淋巴细胞浸润的生物学潜能可能存在困难。聚合酶链反应（PCR）已被用于记录石蜡包埋固定组织中免疫球蛋白重链基因的克隆重排。为了探讨PCR在评估皮肤淋巴细胞浸润中的价值，我们分析了93例存档的非真菌性淋巴细胞病变（28例小细胞或混合性淋巴细胞淋巴瘤、15例大细胞淋巴瘤、40例良性浸润以及10例具有非典型特征的病变）。这些病例之前已在石蜡切片上进行过免疫表型分析，并收集了7至20年的临床随访资料。使用半巢式PCR技术生成DNA产物，通过5%聚丙烯酰胺凝胶电泳进行分离，用溴化乙锭染色，并在紫外光下观察。出现100至120个碱基对条带的病例被判定为阳性。在28例小细胞或混合细胞淋巴瘤中，23例具有B细胞免疫表型或由B细胞和T细胞混合组成；其中，7例（30%）显示出单克隆模式，3例（13%）结果不确定。12例大细胞病例为B细胞或混合性；其中5例（42%）单克隆条带呈阳性，4例（33%）结果不确定。5例T细胞小细胞淋巴瘤或3例T细胞大细胞淋巴瘤均未显示单克隆条带。相比之下，40例良性病例中有39例以T细胞为主或为混合性病变。然而，在这40例病例中，18例在初始检测时提示可能存在单克隆性。6例结果不确定，12例显示明显的单克隆条带，其中4例在重复检测时可重现。这18例病例中有17例不存在淋巴瘤的组织学或临床特征，表明它们代表假阳性结果。后者中的大多数病变显示血管周围浸润稀疏，B细胞极少。这表明从少数淋巴细胞中扩增免疫球蛋白重链基因可能产生单克隆条带。总之，PCR可能为选定的淋巴细胞性皮肤病变的克隆性提供辅助信息，但在这种情况下相当不敏感。由于存在假阳性结果的可能性，在结合组织学、免疫组织学和临床发现进行评估时，尤其是在评估稀疏浸润时，必须仔细考虑这些数据。
