Dermatofibrosarcoma Protuberans in a 12-Year-Old Child: A Rare Case.

Dermatofibrosarcoma protuberans (DFSP) is an uncommon soft tissue tumor involving the dermis and subcutaneous fat that rarely occurs in children, manifested as a slowly growing firm plaque on the trunk. A 12-year-old girl patient presented with dark patch on the nasal root after finishing 25 sessions of radiotherapy. Initially, patient came to Oncology Surgery Clinic at Hasan Sadikin General Hospital Bandung with the chief complaint of a large exophytic mass located in the nasal area, which was neither itchy nor painful. A large, firm, painless mass with no sign of localized heat or redness was found on physical examination. There were no palpable cervical or axillary lymph nodes. Wide local excision and frontal flap procedure were performed by Oncology Surgery Department leaving a pedicle with 2×1.5×1 cm on size was observed. Upon histopathological examination, tumor mass was found in the subepithelium and consisted of oval to spindle-shaped cells that were hyperplastic, compacted, diffuse, forming fasciculus, whorled, and cartwheel. Cell nuclei were pleomorphic (oval to wavy), hyperchromatic, with clear nucleolus, and occasion mitotic figures. Hyalinisation was seen between the tumor masses. On immunohistochemical stains, there were diffuse positivity for epithelial membrane antigen (EMA) and vimentin. Based on the histological and immunohistochemical findings, the diagnosis of stage II DFSP was made. Until now, there is no established algorithm for treatment of DFSP. Wide local excision and radiotherapy for 25 sessions was performed on this patient, resulting in complete tumor mass removal. After three months of observation, the second surgery was done to remove a pedicle; however, there is no recurrence of tumor growth. Despite its rarity, DFSP should be considered as a differential diagnosis to avoid underdiagnosis or misdiagnosis.