Coexistence of giant cell fibroblastoma and encephalocele.

Giant cell fibroblastoma (GCF) is a rare soft tissue tumour that occurs almost exclusively in children younger than 10 years of age and is mostly located in the superficial soft tissues of the back and thighs. We present a rare case of GCF with encephalocele in a 1.5-year-old boy who presented with a swelling in the occipital area of the scalp since birth. CT scan suggested encephalocele without any suspicion of a mass lesion. On histopathology, an ill-defined proliferation of fibroblasts in a heavily collagenised and focally myxoid stroma was seen containing numerous multinucleated cells having a floret-like appearance along with mature glial tissue bordering a cystic space. Immunohistochemically, the stromal cells were positive for both, vimentin (diffuse) and CD34 (focal) thereby confirming the histological diagnosis of GCF. This case highlights the unusual coexistence of GCF with congenital defects and its histogenetic resemblance to dermatofibrosarcoma protuberans.