Recurrent adult-type fibrosarcoma of the frontal bone in a child

Primary, adult-type bone fibrosarcoma is an uncommon, malignant spindle-cell tumor of fibroblastic origin, rarely affecting children. Most frequently diagnosed among bone malignancies in the past, improved diagnostic techniques and further restrictive classification criteria have currently made the diagnosis of fibrosarcoma very unusual.We hereby report the case of a 7-year-old child with a right frontal swelling mass. A computed tomography scan showed an osteolytic lesion of the right frontal bone, involving the diploe and the outer table of the skull. An en bloc surgical excision, followed by a thorough immunohistological evaluation, led to the diagnosis of fibroblastic proliferation, with low cellularity and minimal atypias. The patient had four recurrences during the 4-year follow-up. With an increasing histological grade at recurrences, a diagnosis of adult-type fibrosarcoma was made.To the best of the authors’ knowledge, this is the first reported case of an adult-type fibrosarcoma arising in the frontal bone of a child

Desmoplastic Fibroma of the Mandible: A Series of Three Cases and Review of Literature

The desmoplastic fibroma (DF) is a rare, fibroblastic lesion of bone that histologically resembles the desmoid tumor of soft tissue. Although classified as benign, it frequently demonstrates aggressive behavior, often causing tooth mobility, extensive bone destruction, and has a moderate to high recurrence rate. We present three cases of DF in the mandible: the first in a 13 year old female involving the mandibular body in the region of teeth #s 27–#28, the second in a 57 year old female with a lesion apical to tooth #30, and the third in a 20-year-old female involving the left posterior mandible. Clinical, histologic, immunohistochemical (IHC) and radiographic features of this rare neoplasm are discussed. The challenges encountered in establishing an accurate diagnosis due to significant microscopic overlap with other spindle cell lesions are also detailed. Additionally, the findings of IHC stains including vimentin, smooth muscle actin, S-100 protein, β-catenin, HHF-35 and proliferation marker, Ki-67 on 3 cases are reported. The potential for misdiagnosis is high, especially in early lesions, since immunohistochemistry has been reported in literature to be inconsistent when differentiating DFs from other spindle cell lesions. A comparative review of DF and similar entities in the jaws with current considerations in treatment and prognosis is presented