A cell line with multinucleated giant cell formation established from a human giant cell tumor of tendon sheath--preliminary report.

We first established a cell line with unique giant cell formation properties from a human giant cell tumor of tendon sheath (GCTTS) arising in the right ankle of a 7-year-old girl. The specimen for cell culture taken from the tumor was heterotransplanted into the back of a BALB/c (nu/nu) nude mouse. An in-vitro cell line was established from a tumor that grew after this heterotransplantation. Only mononuclear cells were observed in the primary culture, and these remained constant in growth. Multinucleated giant cells appeared at passage 3 and were constantly observed thereafter. The fusion of mononuclear cells into giant cells was verified by light and phase-contrast microscopy. This cell line was confirmed to be derived from a human by karyotype analysis and DNA fingerprinting. The cell-doubling time was 150 h. This cell line should be useful for studies of the mechanism of multinucleation in giant cell tumors.