A cell line termed LC 89 was established from a peritracheal lymph node metastasis removed from a 54-year-old patient who underwent surgery for pulmonary adenocarcinoma. Chromosomal analyses demonstrated structural and numerical aberrations, with a mode of 54 chromosomes per cell and several nonrandom abnormalities. The localization of intermediate filament antigens, low-molecular-weight (LMW) cytokeratins and vimentin, demonstrated a switch from LMW cytokeratins, predominantly expressed in primary tumor cells, to vimentin detected in LC 89 cells that were grown in vitro or transplanted into nude mice. In view of the phenotypic and chromosomal features, LC 89 should provide a useful addition to the cell lines currently available for in vitro and in vivo studies of lung cancer.