Histological and clinical characteristics of malignant giant cell tumor of bone

Abstract

Malignant giant cell tumors of bone (MGCTB) are rare, and the diagnosis can be difficult due to the occurrence of a variety of malignant tumors containing giant cells. To better understand its clinicopathological features, we have reviewed our experience with 17 cases of MGCTB. Five cases were primary malignant giant cell tumor of bone (PMGCTB), and 12 cases were giant cell tumors of bone initially diagnosed as benign but malignant in a recurrent lesion (secondary MGCTB, SMGCTB). The patients included six women and 11 men (age ranged from 17 to 52 years; mean, 30.5 years). The tumor arose in the femur (six cases), the tibia (seven cases), the humerus (three cases), and the fibula (one case). Microscopically, PMGCTB showed both conventional giant cell tumor and malignant sarcoma features. SMGCTB were initially diagnosed as conventional giant cell tumor of bone, the recurrent lesion showing malignant features. Histologically, the malignant components included osteosarcoma (11 cases), undifferentiated high-grade pleomorphic sarcoma (two cases), and fibrosarcoma (four cases). SMGCTB cases showed strong expression of p53. Follow-up information revealed that four patients died of lung metastasis, two patients are alive with lung metastases, and 11 patients are alive without tumor. MGCTB should be considered as a high-grade sarcoma. It must be distinguished from GCTB and other malignant tumors containing giant cells. p53 might play a role in the malignant transformation of GCTB.

Prognostic value of p53 protein expression in giant cell tumor of bone

“…Most of the malignant GCTB evolve years after surgery and are associated with previous radiotherapy or occur de novo. On the other hand, cases of sarcomatous transformation in sites of GCTB following surgery alone have also been reported (so-called primary malignant GCTB) [1,12,13,17,29,30]. Usually the malignant transformation of the GCTB has the morphology of osteosarcoma, fibrosarcoma, or so-called malignant fibrous histiocytoma (secondary malignancy in GCTB) [5,29].…”

“…In most cases, the malignant transformation is diagnosed within five years following primary resection. Various oncogenes and tumor suppressor genes, including p53 and H-ras, are thought to affect this transformation [12,13,17,30]. Okubo et al reported that p53 and high GPX-1 expression is of great help in diagnosing malignant transformation in GCTB [12].…”

Treatment and outcome of malignant giant cell tumor in the spine

“…Although GCT is predominantly regarded as benign lesion, it has malignant potential and could completely transform into malignant one [11]. Only 1.4-9.4 % of GCTs appear in the spine and occur most commonly between the ages of 20-40 years, with a male-to-female ratio of 1:2.5 [1,[3][4][5].…”

“…Primary MGCT (PMGCT), which is often diagnosed at the time of first treatment, has a juxtaposition of conventional giant cell areas and pleomorphic spindle cell areas that are clearly malignant [10]. Secondary malignant giant cell tumor (SMGCT) is a high-grade sarcoma occurring as a recurrent lesion at the site of a benign GCT either after surgery, radiotherapy, or both [9,11]. SMGCT is more common than PMGCT and mainly originates after irradiation treatment for the primary lesion [8,[12][13][14][15][16].…”

Histopathological, immunohistochemical, and image analytic parameters characterizing the stromal component in primary and recurrent giant cell tumor of bone

“…There is marked subjectivity in the histopathological grading systems and many reports on the correlation of histological features and prognosis have concluded that it is impossible to judge whether or not a GCT of bone is likely to recur from its histological characteristics. 4,15 At present, no grading system has proved to have prognostic relevance. Recent understanding of the cellular components of GCT and its molecular and cytokine-mediated derivation has shed new light on the nature of GCT.…”