Desmoplastic fibroma of the mandible: a rare gnathic bone tumor with a review of the literature.

Desmoplastic fibroma (DF) is a rare bone tumor, which is known to involve mostly the gnathic bones. In this setting, the clinical presentation is usually represented by a bulging tumor of the face. Radiologically, the tumor is usually characterized by an expansile lytic bone lesion. The histopathology of the tumor shows a poorly circumscribed hypocellular lesion rich in collagen fibers with interspersed spindle cells having bland nuclear chromatin. Despite the lack of mitoses and nuclear pleomorphism, DF has an aggressive nature, presenting as a destructive growth causing entrapment of neuro-vascular bundles, sinusitis, or trismus. Some cases of DF show mutations in the adenomatous polyposis coli pathway shown by nuclear localization of the β-catenin protein. Few reports showed an association with tuberous sclerosis, though most of these cases were sporadic. We discuss a rare case of desmoplastic fibroma involving the mandible, and a review of the literature of the DF cases involving the gnathic bones.