fibroblastoma that contains giant cells, and is also known as juvenile DFSP. Giant cell fibroblastomas are skin and soft tissue tumors that usually arise in childhood. They are sometimes seen in association with dermatofibrosarcoma protuberans (DFSP, hybrid lesions) or may transform or recur as DFSP. Atrophic DFSP Atrophic DFSP resemble other benign lesions such as morphea, idiopathic atrophoderma, atrophic scar, anetoderma or lipoatrophy. It behaves like classic DFSP. It commonly favours young to middle aged adults. It has a slow infiltrative growth and a high rate of local recurrence if not completely excised. Sclerosing DFSP Sclerosing DFSP is a variant in which the cellularity is low, and the tumor consists of uniform bundles of collagen interspersed with more typical DFSP cells. Granular cell variant is a rare type in which spindle cells are mingled with richly granular cells, the granules being lysosomal, with prominent nucleoli. Fibrosarcomatous DFSP (DFSP-FS) Fibrosarcomatous DFSP, a rare variant of DFSP involving greater aggression, high rates of local occurrences, and higher metastatic potential. DFSP - FS are considered to be intermediate-grade sarcomas, although they rarely metastasize (fewer than 5 percent of cases). Pathophysiology More than 90% of DFSP tumors have the chromosomal translocation t(17;22). The translocation fuses the collagen gene (COL1A1) with the platelet-derived growth factor (PDGF) gene. The fibroblast, the cell of origin of this tumor, expresses the fusion gene in the belief that it codes for collagen. However, the resulting fusion protein is processed into a mature platelet-derived growth factor which is a potent growth factor. Fibroblasts contain the receptor for this growth factor. Thus the cell "thinks" it is producing a structural protein, but it creates a self-stimulatory growth signal. The cell divides rapidly and tumor forms. The tissue is often positive for CD34. Diagnosis DFSP is a malignant tumor diagnosed with a biopsy, when a portion of the tumor is removed for examination. In order to ensure that enough tissue is removed to make an accurate diagnosis, the initial biopsy of a suspected DFSP is usually done with a core needle or a surgical incision. Clinical palpation is not entirely reliable for ascertaining the depth of a DFSP infiltration. Magnetic resonance imaging (MRI) is more sensitive addressing the depth of the invasion on some types of DFSP, particularly large or recurring tumors. Though MRI is less accurate for identifying infiltration to head and neck tumors. Diagnostic delay and misdiagnosis Due to the