TUMOR OF THE GASTROINTESTINAL AUTONOMOUS NERVOUS-SYSTEM (GAN-TUMOR ORPLEXOSARCOMA)

GAN-tumors or plexosarcomas, first described by Herrera et al. in 1984 , are uncommon neurogenic stromal spindle cell tumors of the intestina l tract mainly located in the stomac and the small intestine. The dist inctive immunohistochemical pattern is the positive staining for vimen tin and neuron-specific-enolase. Ultrastructural features are neuron-l ike cells with interdigitating cytoplasmic processes, dense-core neuro secretory granules, the lack of basement membranes and the presence of interstitial skeinoid fibers. Pain, chronic and acute bleeding are th e most frequent but. not specific symptoms and the diagnostic delay is reflectet by a large average diameter of these tumors. For even small er tumors and those with a low mitotic rate may metastasize, GAN-tumor s must be considered malignant and need a radical surgical resection.