MALIGNANT GIANT CELL TUMOR OF TENDON SHEATH Report of a Case

Abstract

In a patient with pigmented villonodular synovitis of the right knee joint, there occurred a malignant giant cell tumor of tendon sheath. There was clinical evidence of metastasis after the second local recurrence and the recurrent tumors were studied enzyme cytochemically and electron microscopically. Ultrastructurally, the malignant tumor consisted of three principal cell types; histiocyte‐like cells, fibroblast‐like cells, and intermediate cells, with unique attendance of myofibroblasts. This may be the first report of the presence of myofibroblasts in malignant giant cell tumor of tendon sheath. Enzyme cytochemistry revealed various functional properties of histiocytes. ACTA PATHOL. JPN. 35 : 699–709, 1985.

Primary tumours of the synovium

“…A review of the literature (Table I) shows that there are only a few reported cases. [22][23][24][25][26][27][28] The largest series of eight cases was reported by Bertoni et al 22 in 1997. It may occur as a primary malignancy or may arise in an area of pigmented villonodular synovitis.…”

Multiple separated giant cell tumors of the tendon sheath in a thumb

“…In the case of malignancy, the histology shows pronounced anaplasia of the tumor cells, few giant cells, frequent mitoses, and focal necrosis. 12,13 Although the rapidly growing nature of the masses in our case suggested the possibility of malignancy, the histologic examination did not reveal any findings of malignancy. The diffuse form of GCTTS also has to be differentiated from the localized form.…”

“…Whether GCTTS is a reactive or neoplastic lesion is controversial, 10,11 but rare cases of malignant GCTTS have been reported. 12,13 Malignant GCTTS is composed of a benign giant cell tumor coexisting with frankly malignant areas, or recurrent GCTTS sometimes appears as a malignant transformation. In the case of malignancy, the histology shows pronounced anaplasia of the tumor cells, few giant cells, frequent mitoses, and focal necrosis.…”

Pigmented villonodular synovitis: Monoclonality and metastasis—a case for neoplastic origin?

“…Therefore, it was particularly striking to find tissue consistent with PVNS in a distant nonsynovial site long after the initial diagnosis and subsequent amputation of the primary site. Metastasis has been noted in one previous report of PVNS, but only following malignant change to a malignant giant cell tumor of the tendon sheath on its second recurrence (Ushijima et al 1985).…”