Giant cell fibroblastoma in a child misdiagnosed as a dermatofibroma.

We report a 9-year-old African-American boy with a giant cell fibroblastoma of the shoulder that was incorrectly diagnosed as a keloid and dermatofibroma. Initial misdiagnosis led to a delay of 4 years in the correct diagnosis, with the tumor producing significant local destruction. We review herein the clinical manifestations, histologic findings, histogenesis, relationship to dermatofibrosarcoma protuberans (DFSP), treatment, and differential diagnosis of giant cell fibroblastoma (GCF). This information is important in correctly diagnosing this uncommon, benign, but locally aggressive and recurrent tumor of childhood. The clinician should consider GCF and DFSP when the pathologic diagnosis of dermatofibroma is made in lesions more than 2 cm in diameter, or when this diagnosis is made in a prepubertal child.