About giant cell tumor, all are true except:
(A) Commonly presents in the 20-40 year age group (B) Matrix consists of proliferating mononuclear cells (C) Osteoclast giant cells constitute the proliferative component of the tumor (D) It is a benign tumor which may have lung metastasis
(C) Ans: C. Osteoclast giant cells constitute the proliferative component of the tumor(Ref: Robbins 9Ie p1204; Apley's 9Ie p202).In giant cell tumors, osteoclast giant cells are the malignant cells, which induce the proliferation of mononuclear macrophage lineage cells, hence the dividing cell population is the mononuclear cells which form the matrix.Osteoclast giant cells do not constitute the proliferative component of the tumor.