The pathological examinations revealed dedifferentiation from low-grade DFSP to higher grade fibrosarcomatous features in the recurrent and metastatic lesions.

• 病理切片检查发现在复发及转移肿瘤细胞出现退行性分化，从低度恶性之隆凸性皮肤纤维肉瘤转变为较恶性的纤维肉瘤。