Stromal tumors of the stomach. Review of our experience and reclassification of a series of patients

OBJECTIVE: to retrospectively review a series of 12 patients operated on in our department for stromal tumor of the stomach. Clinical and morphologica l data, and the patients' postoperative course, were analyzed. METHODS: medical records for 12 patients (mean age 63.3 years) were retrosp ectively reviewed to obtain data on clinical presentation, diagnosis and tr eatment. Surgical morbidity and mortality were analyzed. A pathologist revi ewed the resected specimens to determine the morphological factors of progn ostic value. The biological nature of the tumor was reclassified based excl usively on mitotic index, and all tumors were staged according to the TGM s ystem. Recurrence and survival rates were also calculated. RESULTS: the most frequent clinical presentation was abdominal pain and gas trointestinal bleeding. The most sensitive diagnostic methods were computer ized tomography and echographic endoscopy. Operability and resectability ra tes were 100% and 91.6% respectively. Local resection was done in 5 patient s, partial gastrectomy in 5, and extended total gastrectomy in 1. Histologi cally, 6 cases were muscular tumors (2 leiomyomas, 3 low-grade leiomyosarco mas and 1 high-grade leiomyosarcoma), 2 were gas trointestinal autonomic ne rve (GAN) tumors, and 4 were pure stomal tumors. The morbidity rate was 33. 3% and the mortality rate was 8.3% (1 patient). All patients were followed up: 1 patient each died after 9 months and 4 years, 1 developed liver metas tases after a disease-free interval of 14 months, and the other 9 patients were still alive and free of disease after intervals ranging from 4 months to 7 years. CONCLUSIONS: stromal tumors include a group of tumors which may present mus cular differentiation (the most frequent type), neural differentiation (GAN tumors) or no differentiation at all (pure stromal tumors). The mitotic in dex is the most valid parameter to determine biological nature, considering that classification as a benign tumor requires the total absence of mitose s. Treatment was mostly surgical, and local resection with adequate safety margins was effective. Prognosis was relatively good, but long-term followu p is needed to assess the malignant potential of these tumors.