Primary malignant giant cell tumor of bone with predominant osteosarcoma morphology:a clinicopathological analysis of seven cases
Purpose To elucidate the clinicopathological characteristics of primary malignant giant cell tumor of bone(PMGCTB)with mainly osteosarcoma-like morphology.Meth-ods Clinicopathologic features of 7 cases of PMGCTB were ret-rospectively analyzed.Results Among 7 patients with PMGCTB,there were 4 females and 3 males,aged between 9 and 66 years(mean age 39.5 years,median age 35 years).The distal femur emerged as the most frequent site to be involved(3/6).The main clinical manifestations included pain and swelling at the original site of the tumor.Radiological findings indicated osteolytic lesions,often combined with sclerotic areas;most ca-ses showed cortical bone destruction and soft tissue masses(5/7).Histologically,the majority of tumors exhibited typical mor-phological features of osteosarcoma with a few or without osteo-clast-like multinucleated giant cells.Positive immunoreaction with H3F3A G34W was confirmed in 6 cases and with H3F3A G34V in 1 case.SATB2 and p63 were positive in all cases,p53 was proved to be wild type,the Ki67 proliferation index ranged approximately from 10%to 50%.H3F3A p.G34W mutation was detected in 6 cases and only 1 case harboring H3F3A p.G34V mutation.Conclusion PMGCTB is exceedingly rare and difficult for accurate diagnosis,especially for those with atypical morphological features.A comprehensive analysis involving ra-diological,immunophenotypic,and molecular detection is neces-sary to rule out other high-grade sarcomas.
malignant giant cell tumor of boneosteosarcomaH3F3A