We report a case of reticulum cell sarcoma in the right cervical lymph node of a 42-year-old male. It was a slowly growing, non-tender movable mass of 8 months duration. Microscopically, the lymph node was effaced by proliferating spindle cells arranged in broad sheets, bands, or fascicular patterns in paracortical area sparing of B-cell region. The tumor component was divided by fibrous band. The individual cells had oval to round or elongated nuclei, with inconspicuous nucleoli and moderate amounts of cytoplasms with indistinct cell borders. Pleomorphic large cells with binucleated, or multinucleated bizarre nuclei with prominent nucleoli, were partly admixed. In immunohistochemical stain, the tumor cell was strong positive for S-100 protein, HLA-DR, Mac387 and weakly positive for Leukocyte common antigen and equivocal for Vimentin. But it was negative for CD21, Ki-1, Desmin, Epithelial membrane antigen and Cytokeratin. These immunohistochemical findings suggested that the neoplastic cell was originated from the interdigitating reticulum cell of lymph node. The patient was treated by radiation therapy, and alive well at 37 months of follow-up.