Department of Dermatology, Asahikawa Medical College, Asahikawa, Japan.
Clin Exp Dermatol. 2011 Jan;36(1):57-62. doi: 10.1111/j.1365-2230.2010.03841.x.
Subungual keratoacanthoma (SUKA) is a rare cutaneous tumour with several features distinct from ordinary KA. SUKA may not show spontaneous regression and sometimes grows progressively, resulting in phalangeal bone destruction. This makes its distinction from digital squamous cell carcinoma (SCC) difficult. Aim. To investigate differences in molecular expression between SUKA and digital SCC.
In addition to immunohistochemical analysis of Ki-67, one of the markers differentiating KA from SCC, we investigated the copy numbers of various oncogenes by multiplex ligation-dependent probe amplification (MLPA) using two cases of SUKA and three cases of periungual SCC.
Ki-67 was moderately or strongly positive in SCC but negative in SUKA. The MLPA analysis showed that the nuclear factor (NF)κB1 and cortactin (CTTN; formerly known as EMS1) genes are amplified in SUKA but not in digital SCC. This increase in NFκB1 was confirmed by immunohistochemical analysis.
NFκB1 could be a novel marker to differentiate between SUKA and SCC. Although this study was performed on limited numbers of patients with SUKA, MLPA analysis could be applied to differentiate other benign tumours from their malignant counterparts.
甲下角化棘皮瘤（SUKA）是一种罕见的皮肤肿瘤，与普通角化棘皮瘤有几个不同的特征。SUKA 可能不会自发消退，有时会逐渐生长，导致指骨破坏。这使得它与指部鳞状细胞癌（SCC）难以区分。目的：研究 SUKA 和指部 SCC 之间分子表达的差异。
除了用 Ki-67（区分 KA 和 SCC 的标志物之一）进行免疫组织化学分析外，我们还使用两种 SUKA 病例和三种甲周 SCC 病例，通过多重连接依赖性探针扩增（MLPA）检测各种癌基因的拷贝数。
SCC 中 Ki-67 呈中度或强阳性，而 SUKA 则为阴性。MLPA 分析显示，核因子（NF）κB1 和皮质肌动蛋白（CTTN；以前称为 EMS1）基因在 SUKA 中扩增，但在数字 SCC 中不扩增。NFκB1 的增加通过免疫组织化学分析得到证实。
NFκB1 可能是区分 SUKA 和 SCC 的新标志物。尽管本研究对 SUKA 患者的数量有限，但 MLPA 分析可用于区分其他良性肿瘤与其恶性对应物。
