Keratoacanthoma (KA) is a common cutaneous neoplasm which often resembles typical squamous cell carcinoma (SCC) in both its clinical and historical presentation. Several studies have attempted to identify methods for distinguishing between KA and SCC, however, none of these have proven to play any obvious roles in these tumors. Given this we went on to evaluate mitochondrial microsatellite instability (mtMSI) in KA and SCC in an effort to understand these tumors better. DNA was isolated from paired normal and tumoral tissues donated by 57 KA patients and 43 SCC patients. MtMSI was then analyzed using eight microsatellite markers and was observed in 2 (3.5%) of the 57 KA patients and 8 (18.6%) of the 43 SCC patients, respectively. MtMSI was also shown to affect different locations depending on tumor type. In KA patients, mtMSI was detected at mitochondrial D514 D-loop and presented with (CA) n repeats, in contrast, all of the SCC patient experienced mtMSI at the D310 with (C)n repeats of the D-loop region. These differences in location were found to be significant, which may support the hypothesis that KA and SCC have different pathogenetic pathways. Our results also suggest that mtMSI may be a candidate for developing novel differential diagnostic methods for KA and SCC.

角化棘皮瘤 (KA) 是一种常见的皮肤肿瘤，其临床和历史表现通常类似于典型的鳞状细胞癌 (SCC)。几项研究试图确定区分 KA 和 SCC 的方法，然而，这些方法都没有被证明在这些肿瘤中发挥任何明显的作用。鉴于此，我们继续评估 KA 和 SCC 中的线粒体微卫星不稳定性（mtMSI），以更好地了解这些肿瘤。从 57 名 KA 患者和 43 名 SCC 患者捐赠的配对正常和肿瘤组织中分离出 DNA。然后使用八种微卫星标记分析 MtMSI，分别在 57 名 KA 患者中的 2 名（3.5%）和 43 名 SCC 患者中的 8 名（18.6%）中观察到。MtMSI 还被证明会影响不同的位置，具体取决于肿瘤类型。在 KA 患者中，Ñ重复，与此相反，所有的SCC患者中的与（C）n中的d-环区的重复的D310经历将MTMSi。发现这些位置差异是显着的，这可能支持 KA 和 SCC 具有不同致病途径的假设。我们的结果还表明，mtMSI 可能是开发新的 KA 和 SCC 鉴别诊断方法的候选者。