明細胞肉腫の1例

概要

論文の詳細を見る
We reported a case of 58-year-old woman of clear cell sarcoma on the lateral side of the left knee. About 8 years ago, she had a small verrucous tumor on the left knee and tumor was excised by a local doctor. Histological examination was not performed.She noticed a subcutaneous tumor on the lateral side of previous operation scar around December 1996. The tumor was excised by same doctor at July 1997. Histological examination, fibrous tissue septa divided the tumor into well-defined nests and groups of pale-staining tumor cells. Immnunohistochemically, The tumor was positive for S-100 protein but negative for HMB45 staining. The tumor reccurented on the same place at November 1997, the patient was referred to our department. At this time, tumor measured 2cm under the previous operation scar. We performed an extended excision and inguinal lymphonodes resection. Histologically, we got same findings. But immnunohistochemically, The tumor was partially positive for HMB45 staining.In electron microscopy, some melanosomes were found in tumor cells. Although it is difficult to distinguish between clear cell sarcoma and metastatic amelanotic melanoma, we diagnosed this tumor as clear cell sarcoma.