Congenital infantile fibrosarcoma mimicking a cutaneous vascular lesion: a case report and review of the literature.

Congenital infantile fibrosarcoma (CIFS) is a rare neoplasm of infancy that occurs most frequently in the extremities, and when presenting in the skin, may sometimes resemble infantile hemangiomas or other vascular lesions. Clinically, these tumors differ from hemangiomas in the time of onset, morphology, and growth pattern and must be evaluated histologically for definitive diagnosis. We describe an infant with a neoplasm involving the distal left forearm initially presumed to be a vascular lesion after evaluation by two separate ultrasound studies. He presented at seven weeks of life with a multinodular lesion that had enlarged significantly since birth, and the skin biopsy revealed a fibrosarcoma. This case highlights an unusual cutaneous presentation of CIFS, which varies in appearance from the previous 12 cases reported in the literature. We review the clinical manifestations of these congenital masses and emphasize early diagnosis for conservative therapy and improved prognosis.