Parosteal Osteosarcoma of the skull: Pathophysiological and imaging review

Parosteal osteosarcoma of the temporal bone: Case report

“…Osteosarcoma is a type of sarcoma; further subclassification is done based on its location within the bone and histological features ( Fig. 1 ) [3] . POS is the most well differentiated low-grade variant, when compared to the other surface osteosarcomas.…”

“…The first case of POS in the craniofacial region was reported 10 years later [2] . POS of the temporal bone is exceeding rare with only 4 cases found in modern literature [3] . Presentation of POS can range from an asymptomatic mass to a severely painful lesion causing reduced joint mobility, skin ulcerations, and lymphadenopathy [4] .…”

“…Presentation of POS can range from an asymptomatic mass to a severely painful lesion causing reduced joint mobility, skin ulcerations, and lymphadenopathy [4] . A broad differential diagnosis is essential which includes benign and malignant tumors, metastatic lesions, and sequalae of injury [3] . Clinical features, laboratory testing, imaging, and histopathological examination are all used to reach a diagnosis [2] .…”

“…Characteristic features of POS on imaging include sunburst appearance and the so-called string sign. Both CT scan and MRI are used for clinical staging of the tumor [ 2 , 3 ]. CT scan is used initially due to its faster image acquisition, differentiates benign from malignant lesions based on their architecture, and rules out metastasis [ 3 , 4 ].…”

“…Both CT scan and MRI are used for clinical staging of the tumor [ 2 , 3 ]. CT scan is used initially due to its faster image acquisition, differentiates benign from malignant lesions based on their architecture, and rules out metastasis [ 3 , 4 ]. MRI is used to rule out recurrence of malignancy, bone marrow infiltration, or any soft tissue component of the lesion [5] .…”