Flaig M J, Schuhmann K, Sander C A
Department of Dermatology, Ludwig-Maximilians-Universitaet, Munich, Germany.
Semin Cutan Med Surg. 2000 Jun;19(2):87-90. doi: 10.1016/s1085-5629(00)80004-8.
The diagnosis and classification of cutaneous lymphomas is a challenge for the dermatopathologist. This is particularly true for determining the distinction between a malignant lymphoma and a benign reactive infiltrate (pseudolymphoma). Recent advances in molecular genetics, as the determination of clonality of lymphoid infiltrates, have emerged as an important tool to overcome these diagnostic dilemmas. In our experience, more than 90% of cutaneous T-cell lymphomas have a rearrangement of the T-cell receptor gamma chain gene, whereas clonal rearrangements in cutaneous T-cell pseudolymphomas could not be found. However, the demonstration of clonality does not necessarily indicate malignancy. There have been several reports that have identified clonal lymphoid proliferations in pityriasis lichenoides et varioliformis acuta, pseudolymphomas, and lichen planus. For this reason one must carefully evaluate the information that is provided by these techniques. The results should always correlate with clinical, histologic, and immunophenotypic data to achieve the correct diagnosis.
皮肤淋巴瘤的诊断和分类对皮肤病理学家来说是一项挑战。在确定恶性淋巴瘤与良性反应性浸润（假性淋巴瘤）之间的区别时尤其如此。分子遗传学的最新进展，如确定淋巴样浸润的克隆性，已成为克服这些诊断难题的重要工具。根据我们的经验，超过90%的皮肤T细胞淋巴瘤存在T细胞受体γ链基因重排，而在皮肤T细胞假性淋巴瘤中未发现克隆性重排。然而，克隆性的证明并不一定意味着恶性。有几份报告指出，在急性痘疮样苔藓样糠疹、假性淋巴瘤和扁平苔藓中发现了克隆性淋巴样增殖。因此，必须仔细评估这些技术提供的信息。结果应始终与临床、组织学和免疫表型数据相关联，以实现正确诊断。
