Oyama Noritaka, Kaneko Fumio
Dermatology and Dermato-Allergology Clinic, Research Institute for Neuroscience, Southern Tohoku General Hospital, Fukushima, Japan.
J Dermatol. 2008 Dec;35(12):782-5. doi: 10.1111/j.1346-8138.2008.00569.x.
The secondary skin malignancies arising in seborrheic keratosis (SK) are uncommon, and the causal association between the pre-existing lesion and subsequent malignant transformation remains uncertain. Among these enigmatic conditions, trichilemmal differentiation and/or neoplasms in SK have rarely been reported thus far. Herein, we describe a case of invasive trichilemmal carcinoma arising in a long-standing SK of the abdominal skin, and clinicopathologically review this rare complication with a computerized medical published work search (PubMed) and citations from earlier reports. To our knowledge, only four cases of trichilemmal tumors arising in SK have been observed, and, interestingly, all cases, including ours, were Japanese. Four of five cases (80%) developed the tumors in non-sun-exposed SK, and indeed had no apparent actinic damage in the histology. The pre-existing SK itself is more likely to act as the primary pathogenic event for developing the secondary trichilemmal tumors than a coincidental phenomenon and a consequence of skin damage by cumulative sun exposure.
脂溢性角化病（SK）中发生的继发性皮肤恶性肿瘤并不常见，先前存在的病变与随后的恶性转化之间的因果关系仍不确定。在这些难以解释的情况中，SK中的毛囊分化和/或肿瘤迄今为止鲜有报道。在此，我们描述了一例发生于腹部皮肤长期存在的SK的侵袭性毛囊癌病例，并通过计算机化医学文献检索（PubMed）和早期报告的引用对这一罕见并发症进行临床病理回顾。据我们所知，仅观察到4例起源于SK的毛囊肿瘤，有趣的是，包括我们的病例在内，所有病例均为日本人。5例中有4例（80%）在非阳光暴露部位的SK中发生肿瘤，且组织学上确实没有明显的光化性损伤。先前存在的SK本身更有可能是继发性毛囊肿瘤发生的主要致病因素，而非偶然现象以及累积阳光照射导致皮肤损伤的结果。
