Objective: To retrospectively review a series of 12 patients operated on in our department for stromal tumor of the stomach. Clinical and morphological data, and the patients' postoperative course, were analyzed.
Methods: Medical records for 12 patients (mean age 63.3 years) were retrospectively reviewed to obtain data on clinical presentation, diagnosis and treatment. Surgical morbidity and mortality were analyzed. A pathologist reviewed the resected specimens to determine the morphological factors of prognostic value. The biological nature of the tumor was reclassified based exclusively on mitotic index, and all tumors were staged according to the TGM system. Recurrence and survival rates were also calculated.
Results: The most frequent clinical presentation was abdominal pain and gastrointestinal bleeding. The most sensitive diagnostic methods were computerized tomography and echographic endoscopy. Operability and resectability rates were 100% and 91.6% respectively. Local resection was done in 5 patients, partial gastrectomy in 5, and extended total gastrectomy in 1. Histologically, 6 cases were muscular tumors (2 leiomyomas, 3 low-grade leiomyosarcomas and 1 high-grade leiomyosarcoma), 2 were gastrointestinal autonomic nerve (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 metastases 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 muscular differentiation (the most frequent type), neural differentiation (GAN tumors) or no differentiation at all (pure stromal tumors). The mitotic index is the most valid parameter to determine biological nature, considering that classification as a benign tumor requires the total absence of mitoses. Treatment was mostly surgical, and local resection with adequate safety margins was effective. Prognosis was relatively good, but long-term follow-up is needed to assess the malignant potential of these tumors.