Chondroblastic osteosarcoma

Abstract

The purpose of this paper is to report a case of chondroblastic osteosarcoma in the region of the maxilla, with 5 months of evolution. The term osteosarcoma refers to a heterogeneous group of malignancies with bone formation or mesenchymal tissue with histopathological evidence of osteogenic differentiation. The pattern of chondroblastic osteosarcoma represents 25% of all reported cases of this neoplasm. Its histopathological diagnosis is based on the predominance of a chondroid matrix formed in the midst of neoplastic cells. A woman patient, 27-year old, melanoderm, presented on extraoral exam with facial asymmetry caused by the a swelling in the premaxillary region with upper lip protrusion. Intraoral exam showed a maxillary tumefaction with involvement of the vestibular and palatine regions. The computerized tomography (CT) analysis exhibited a radiolucent mass with dispersed areas of radiopacity, with poorly defined and indistinct peripheral edges. The patient was subjected to incisional biopsy and histopathological examination showed the presence of a malignant neoplasm of mesenchymal origin characterized by the presence of irregular bone trabeculae dispersed among mildly atypical chondroblastic cells. The World Health Organization (WHO) recognizes several variants that differ in location, clinical behavior and degree of cellular atypia. The conventional or classical osteosarcoma is the most frequent variant, which develops within the medullary bone. This report illustrates the rapid evolution of one of the histological variants of osteosarcoma.

Single-cell RNA landscape of intratumoral heterogeneity and immunosuppressive microenvironment in advanced osteosarcoma

“…It is important to note that there were malignant osteoblastic cells in the chondroblastic OS lesions based on H&E staining examination, which were further supported by the scRNA-seq that the cells expressing both COL1A1 and SOX9 were identified in the chondroblastic OS lesions BC20 and BC22. Previous study suggested that chondrocytes could undergo a direct transdifferentiation process into osteoblasts during the endochondral ossification in bone formation 70 . With the CNV clonal analysis by inferCNV with the scRNA-seq revealed a large scale genomic copy message, we found a great portion of genomic CNV pattern shared between the chondroblastic and osteoblastic malignant subclones in chondroblastic OS lesions.…”

Prognostic factors to survival of patients with chondroblastic osteosarcoma

“…The resection with tumor-free margins and systemic chemotherapy are the standard treatment option. [ 3 , 7 , 21 , 22 ] Osteosarcoma is quite resistant to radiotherapy. However, in special locations where surgery is not feasible or for cases of bone metastases or in multifocal osteosarcoma, radiotherapy can prolong survival, and decrease pain intensity.…”

“…[ 1 – 6 ] It is characterized by predominant presence of chondroid matrix, which tends to exhibit a high degree of hyaline cartilage and is intimately associated with the non-chondroid element (osteoid or bone matrix). [ 7 ]…”

“…It is important to distinguish the COS from other subtypes, as gene expression, chemotherapy response and prognosis of the subtypes of osteosarcoma are different from each other. [ 3 , 8 – 11 ] There have been rare case reports describing diagnosis, treatment strategies and prognosis of COS. [ 3 , 7 , 12 – 16 ] However, its clinical characteristics have never been described due to low incidence. Although features of osteosarcoma have been frequently reported, there is controversial evidence as to whether there is prognostic differentiation among its subtypes.…”

Intraoperative considerations in a patient with chondroblastic osteosarcoma and saddle pulmonary embolism undergoing amputation

“…1 Chondroblastic osteosarcoma represents approximately 25% of all osteosarcoma diagnoses, and its diagnosis is based on the predominance of a chondroid matrix within the neoplastic cells. 2 Patients diagnosed with osteosarcoma typically present with pain and swelling, and the diagnosis can be easily delayed due to other suspected and much more benign disease processes such as trauma, arthritis, or growing pains. 3 Osteosarcoma is typically graded as low grade, high grade, or metastatic.…”