Abstract: Congenital dermatofibrosarcoma protuberans (DFSP) is rare and its clinical manifestations can mimick vascular lesions. Myxoid DFSP is a unique type with characteristic pathological changes whose biological behavior belongs to borderline malignancy/potential low malignancy. Congenital myxoid DFSP is more rare, with only two sporatic case reported abroad. Herein, we report a case and review related literature. The patient was an one year and nine months old female who had a tumor on her back since she was born. She was misdiagnosed as hemangioma in other hospitals and was treated with external medication of timenol hydrochloride eyedrops for 1 year with poor results. The tumor gradually increased. Combined with histopathological and immunohistochemical changes, a diagnosis of congenital myxoid DFSP was made in our hospital. Considering the closest distance of the bottom margin was only 0.25mm, she was treated with 1cm wide resection of the margin according to the protocols. No recurrence or metastasis was found in the 2 years of follow-up.

Key words: dermatofibrosarcoma protuberans, congenital dermatofibrosarcoma protuberans, myxoid dermatofibrosarcoma protuberans