CASE REPORTS   

Chirurgia 2007 April;20(2):97-100

Copyright © 2007 EDIZIONI MINERVA MEDICA

language: English

Gastroinetstinal stromal tumors: two clinical cases

Donisi M., Salvati V., Sivero L., Romano E., Muto G., Patrone F., Compagna R., Simeoli I., Esposito D., Formisano G., Conte P., Antonino A., Guida F., Rusciano A., Avallone U.

Dipartimento di Chirurgia Generale Geriatrica ed Endoscopia Diagnostica ed Operativa Università degli Studi di Napoli “Federico II”, Napoli

Gastrointestinal stromal tumor (GIST) is a mesenchymal spindle cell (70-80%) or epithelioid (20-30%) neoplasm. “GIST” is relatively new therminology, theese would once have been called leiomyomas, leiomyoblastomas and/or leiomyosarcomas. GISTs occur more often in stomach (50%), followed by small bowel (30%; ileum>jejunum>duodenum), the colon-rectum and the esophagus (20%). The diagnosis is based on a positive c-kit (CD117) stain, which is a tyrosine kinase growth factor receptor. Gain of function mutations of c-kit gene are found in many GISTs and these mutations result in costitutive activation of c-kit protein that stimulates proliferation of GIST tumor cells and may inhibit apoptotic cell death. Some of these tumors respond drammatically to STI571 (Gleevec), which is highly effective in vitro in reducing c-kit tyrosine-kinase activity. The majority are benign, 10-30% are malignant. The differentiation is made according to the number of mitoses counted during hystological examination. Several factor increase the likelihood of malignancy in GISTs. Theese include extragastric location, size greater than 5 cm, central necrosis extention into adjacent organs and metastases (occurring in liver and peritoneum much more frequently than in the lung, bone or lymphonodes). First choice treatment is still nowadays surgical excission though medical progresses will probably change in the future the therapeutic approach.