Low-magnification examination of a desmoplastic fibroblastoma is shown. The lesion is a well-circumscribed ovoid or fusiform mass. The characteristic hypocellularity is apparent at low power.
Although most desmoplastic fibroblastomas are subcutaneous, some involve skeletal muscle
, to which this lesion closely abuts.
High magnification shows stroma that is densely collagenous and contains spindle and stellate fibroblasts in patternless distributions. The vessels are inconspicuous.
This image of desmoplastic fibroblastoma shows the sparsely cellular nature of the lesion. The stroma can be myxoid
in some cases. Although cells may be plump, no true atypia is seen, and mitotic figures are rare or absent.
