Gastrointestinal stromal tumors--a recently defined entity. Literature data and personal case report.

Stromal tumors of the gastrointestinal tract are controverted tumoral entities which were recently delimited. They were initially identified by immunohistochemical investigation and processing of the gastrointestinal muscular tumors and of the malignant and benign nervous tumors. Those investigations were subsequently amplified by electronmicroscopic studies and observations during the patient's prognostic follow-up. Within these circumstances, monoclonal tumors responsive to smooth muscular antigens (actin, SMA), to polyclonal antigens reacting to S-100, PGP 9.5, NSE and GEAP were identified. Thus, tumors with a nervous origin known as a gastrointestinal nerve tumors or plexosarcomas were differentiated, taking into account the difficulty of their distinguishing from gastrointestinal tumors (GIST) which also shows multinucleated great cells. There were also difficulties in defining bidirectionally differentiated tumors or those nonresponsive to any antigen, all these elements proving their origin from nondifferentiated mesenchymal cells. These data are presented in a personal case report of a 28-year old woman with an acute anteroenteral invagination due to a gastrointestinal stromal tumor, favorably removed by surgery and with a postoperative outcome.