tenosynovial giant cell tumor (MONDO_0002522, a Monarch Disease Ontology identifier) is a tumor usually arising in the synovium of joints, bursa or tendon sheath. It is characterized by the presence of mononuclear cells, multinucleated osteoclast-like giant cells, hemosiderin-laden macrophages, foam cells, and an inflammatory infiltrate. According to the growth pattern, it is classified as localized or diffuse. Also known as: fibrous histiocytoma of tendon sheath, giant cell neoplasm of Tenosynovium, giant cell neoplasm of tendon sheath, giant cell neoplasm of the Tenosynovium, giant cell tumor of Tenosynovium, giant cell tumor of tendon sheath, giant cell tumor of the Tenosynovium, giant cell tumour of Tenosynovium.