Periosteal osteosarcoma of the mandible

Unraveling molecular signatures in rare bone tumors and navigating the cancer pathway landscapes for targeted therapeutics

Rare cancers (RCs), which account for over 20% of cancer cases, face significant research and treatment challenges due to their limited prevalence. This results in suboptimal outcomes compared to more common malignancies. Rare bone tumors (RBTs) constitute 5-10% of rare cancer cases and pose unique diagnostic complexities. The therapeutic potential of anti-cancer drugs for RBTs remains largely unexplored. Identifying molecular alterations in cancer-related genes and their associated pathways is essential for precision medicine in RBTs. Small molecule inhibitors and monoclonal antibodies targeting specific RBT-associated proteins show promise. Ongoing clinical trials aim to define RBT biomarkers, subtypes, and optimal treatment contexts, including combination therapies and immunotherapeutic agents. This review addresses the challenges in diagnosing, treating, and studying RBTs, shedding light on the current state of RBT biomarkers, potential therapeutic targets, and promising inhibitors. Rare cancers demand attention and innovative solutions to improve clinical outcomes.

Parosteal osteosarcoma: Case report and review of the literature

BACKGROUND

The majority of osteosarcoma cases of the head and neck are high-grade lesions. We present a case and discuss the diagnostic and therapeutic implications of a rare low-grade parosteal osteosarcoma of the maxilla.

METHODS

A 32-year-old man presenting to the Head and Neck Surgical Oncology clinic with a 1-year history of a firm palatal mass. Evaluation clinically and radiographically raised the suspicion of an osteosarcoma.

RESULTS

A partial maxillectomy revealed a parosteal osteosarcoma with negative margins. No adjuvant therapy was recommended, and the patient remains without evidence of local recurrence after 3 years.

CONCLUSIONS

Parosteal osteosarcomas of the head and neck region are rare, low-grade variants of osteosarcoma, but have the potential to recur with simple local excision. Clinical and radiographic features are diagnostically helpful. Definitive diagnosis comes from histopathology, and wide local resection should be employed as the optimal treatment.

Imaging of periosteal osteosarcoma: radiologic-pathologic comparison

PURPOSE

To review the imaging appearance of periosteal osteosarcoma, with pathologic comparison.

MATERIALS AND METHODS

Data for 40 pathologically confirmed periosteal osteosarcomas were retrospectively reviewed. Patient demographic data were recorded, and radiographs (n = 40), bone scintigrams (n = 10), angiograms (n = 2), and computed tomographic (CT) (n = 11) and magnetic resonance (MR) (n = 12) images were evaluated for lesion location and size, cortical changes, marrow involvement, and intrinsic characteristics by two musculoskeletal radiologists, with agreement by consensus. Pathology reports were reviewed for presence and predominance of histologic components (fibrous, chondroid, and osteoid), tumor grade, and marrow involvement.

RESULTS

There were 25 male (62%) and 15 female (38%) patients with an age range of 10-37 years (average age, 20 years). The most frequent lesion locations were the diaphysis of the tibia (16 patients) or of the femur (15 patients). Radiographs showed a broad-based soft-tissue mass that was attached to the cortex (all patients) and showed cortical thickening (33 patients), cortical scalloping/erosion (37 patients), and/or perpendicular periosteal reaction (38 patients) extending into the soft-tissue mass. Soft-tissue masses were well defined in 91%-100% of cases and surrounded a median of 50%-55% of the cortex. Lesions commonly showed low attenuation at CT (10 patients) and high signal intensity on T2-weighted MR images (10 patients), reflecting the high water content of these largely chondroblastic lesions. Focal areas of adjacent marrow replacement were common at MR imaging (nine patients) but represented reactive changes unless they were in direct continuity with the overlying soft-tissue mass (this was rare, occurring in only one patient, and represented marrow invasion). Review of pathology reports revealed that all lesions contained chondroid tissue, which predominated in 34 patients.

CONCLUSION

The radiologic appearance of periosteal osteosarcoma is a broad-based surface soft-tissue mass causing extrinsic erosion of thickened underlying diaphyseal cortex and perpendicular periosteal reaction extending into the soft-tissue component. Reactive marrow changes are commonly seen at MR imaging, but true marrow invasion is rare.

Malignant tumors of the mandible and maxilla

Malignant tumors of the mandible and maxilla are grouped into primary tumors that originate within the mandible and secondary lesions, predominantly oral cancers and metastatic lesions, that involve the mandible secondarily. The most common malignant tumors of the mandible represent SCCs of the oral cavity, notably carcinoma of the floor of the mouth and gingiva that invade the mandible secondarily. Metastatic disease, most commonly from the breast and lung, are not an uncommon malignant lesion in the mandible and may be the first manifestation of a malignant lesion outside the head and neck. The osteogenic sarcoma is the most common sarcomatous lesion in the mandible and is suggested when a bone-forming matrix with sclerosis is found within the tumor on CT images. Some benign lesions may mimic a malignant tumor on imaging studies. In such cases, a biopsy is indicated to establish the diagnosis by histopathologic means. CT is indicated for assessment of bone destruction in the mandible before surgery or radiation therapy. MR imaging is the optimal modality for the assessment of marrow involvement and evaluation of the extraosseous soft tissue component. Finally, conventional films, frequently a Panorex view, are the initial radiographic examinations in suspected lesions.