ABSTRACT
Chassaignac first described about a benign soft-tissue mass in 1852, characterised by a pleomorphic cell population, which includes lipid-laden foam cells, multinucleated giant cells and round or polygonal stromal cells, often with deposits of haemosiderin in a collagenous stroma. and he overstated their biologic potential in referring to them as fibrous xantoma or Giant-cell tumour of the tendon sheath. They are of two types, Localized (common) and Diffuse (rare) .The rare diffuse form is considered the soft tissue counterpart of diffuse pigmented villonodular synovitis (PVNS) and typically affects the lower extremities1 .Its anatomic distribution parallels that of PVNS, with lesions most commonly found around the knee, followed by the ankle and foot; however, it occasionally affects the hand.