Sajjadeh Movahedinia; Tina Shooshtarizadeh; Hassan Mostafavi
Abstract
The malignant transformation of conventional giant cell tumor of bone (GCTOB) is rare and usually occurs with irradiation. Here we report two neglected cases of conventional GCTOB with spontaneous malignant transformation at 11 and 16 years after initial diagnosis. In the former case, the patient refused ...
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The malignant transformation of conventional giant cell tumor of bone (GCTOB) is rare and usually occurs with irradiation. Here we report two neglected cases of conventional GCTOB with spontaneous malignant transformation at 11 and 16 years after initial diagnosis. In the former case, the patient refused to receive any treatment following the incisional biopsy, and in the latter, the first recurrence that occurred 5 years after initial treatment, was neglected. Although rare, the occurrence of sarcomatous changes in these cases indicates that secondary malignant transformation may be part of the natural course of this tumor. In addition, in both cases, immunohistochemistry showed diffuse and strong p53 expression in the malignant tumor but not in the primary lesion. It suggests that p53 overexpression may play a key role in the malignant transformation of GCTOB and that investigating for p53 expression in recurred lesions may help in predicting cases of giant cell tumor, prone to malignant transformation.
Reza Ataei; Alireza Khooei; Mohammad Gharedaghi
Volume 5, Issue 2 , March 2010, , Pages 53-59
Abstract
Background and Objectives: Giant cell Tumor of bone (GCT) is often regarded as a benign tumor, but its clinical course is unpredictable, has a high rate of recurrence, and even can metastases and transform to a malignant tumor. Histological features of the tumor often could not predict its future ...
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Background and Objectives: Giant cell Tumor of bone (GCT) is often regarded as a benign tumor, but its clinical course is unpredictable, has a high rate of recurrence, and even can metastases and transform to a malignant tumor. Histological features of the tumor often could not predict its future biologic behavior, so it is just called ''Giant cell tumor'' without indicating malignancy or benignicity. Several methods are suggested to predict the biologic behavior of this tumor. This study evaluated the relation between Bax & bcl-2 as proteins involved in cell proliferation and death (apoptosis) with histopathologic features and clinical course of GCT. Materials & Methods: Paraffin- embedded tissue specimens of 40 GCTs of conventional, aggressive, recurrent, malignant, & metastatic types were evaluated by immunohistochemistry for Bax & bcl-2 markers. Clinicopathologic features and immunohistochemical results were statistically analyzed and presented in tables & diagrams. Results:Age, sex, and pattern of skeletal involvement were the same as other worldwide reports. Expression of Bax & bcl-2 markers were significantly higher in malignant GCTs but no statistically significant difference was found in other subtypes for bcl-2 while there was statistically significant difference between subgroups for Bax. Conclusion:Considerable expression of Bax & bcl-2 markers in a GCT could signal its malignant course, but low expression is not valuable in predicting the clinical course. In addition, it seems that secondary tumor nodules in lung are just simple implantation not true malignant metastases