DOI: 10.36347/sjmcr.2021.v09i03.027

Pages: 292-294

Clear cell sarcoma (CCS) of soft tissue or soft tissue melanoma is a rare malignant tumor in young adults, preferentially affecting the lower limbs. We report a new observation of a 17-year-old patient, without a significant history, consulted for a nodular lesion of the left ankle, painless, appeared 06 months before, evolving in a context of general impairment. The clinical examination found a purplish nodule, about 2/2 cm, hard, fixed, associated with multiple nodular lesions along the homolateral lower limb, with the presence of homolateral inguinal lymphadenopathy. There was no associated motor or vascular disorder. The nodule ultrasound showed a mass of soft tissue, hypoechogenic, heterogeneous. The computed tomography of the ankle revealed a lesional process of the medial face infiltrating the tendon and ligament structures and encompassing the posterior tibial artery. Histological examination showed round cell malignant tumor proliferation. The immuno-histochemical supplement showed an expression of the S100 protein and monoclonal antibody HMB-45 by tumor cells. The biopsy of an inguinal node affirmed its metastatic nature. The anatomo-clinical confrontation allowed to retain the diagnosis of clear cell sarcoma. The extension assessment made of a chest-abdominal-pelvic computed tomography showed metastatic lymph nodes intra and retroperitoneal. The patient was given chemotherapy (ifosfamide-adriamycin). Sarcoma with clear soft tissue cells or melanoma of the soft parts is a rare malignant tumor. It occurs most often in young adults at the lower limbs. It is a firm subcutaneous mass, slowly progressive, well limited, usually deep attached to tendon and aponeurotic structures. The positive diagnosis is based on histology coupled with immunohistochemistry. It can be helped by molecular biology in case of doubt diagnosis with melanoma. Its poor prognosis requires early and adequate management.