Interdigitating cell sarcoma. A morphologic, immunohistologic, and enzyme-histochemical study.

A 58-year-old man presented with an unusual sarcoma of the cervical lymph node. The tumor also involved the mesenteric lymph node and jejunum. Tumor cells possessed intracytoplasmic S100 protein, Leu-3a (T4), and HLA-DR antigens. The neoplastic cells also showed membranous ATPase activity. LeuM1, T6, Leu1, Leu2a, B1, lysozyme, and immunoglobulin were not recognized. Their fine structure was similar to that of interdigitating cells. These data are consistent with derivation from lymph node interdigitating reticulum cell.