Weidner N, Foucar E
Arch Dermatol. 1985 Aug;121(8):1041-3. doi: 10.1001/archderm.121.8.1041.
Two unusual cases of squamous cell carcinoma (SCCa) metastatic to skin from distant sites occurred. In both metastatic sites, the malignant squamous epithelium fused with benign surface epithelium, and the resulting transition simulated that typically seen in primary cutaneous SCCa. We believe that this previously unreported phenomenon is an expression of the natural tendency of squamous epithelium to "heal" denuded connective tissue surfaces by proliferation followed by epithelial fusion. Because epithelial continuity can be established between benign keratinocytes and metastatic SCCa, one cannot rely on this single morphologic finding to separate primary from metastatic disease.
出现了两例远处部位转移至皮肤的鳞状细胞癌（SCCa）罕见病例。在两个转移部位，恶性鳞状上皮与良性表面上皮融合，由此产生的过渡类似于原发性皮肤SCCa中常见的情况。我们认为，这种先前未报道的现象是鳞状上皮通过增殖继而上皮融合来“修复”裸露结缔组织表面的自然倾向的一种表现。由于良性角质形成细胞与转移性SCCa之间可建立上皮连续性，因此不能仅依靠这一单一形态学发现来区分原发性疾病和转移性疾病。
