Clinicopathologic and immunohistochemical features of gastrointestinal stromal tumors: a single-center experience

Abstract

IntroductionHere we present our 10-year experience regarding gastrointestinal stromal tumors (GISTs) in terms of clinicopathologic features and immunohistochemical staining patterns.Material and methodsIn this single-center retrospective study, during 2008–2018, data of 26 patients with histologically confirmed diagnoses of GISTs were collected. All patients included in the study underwent surgical resection. The Mann-Whitney U test was used for continuous variables.ResultsThe mean age of the patients was 60.7 ±10.4 (35–79) years. The most common GIST location was the stomach (88.5%). The mean tumor size was 5.8 cm (1–13 cm) and the most common histologic type of GIST was spindle cell (61.5%). CD 117(c-kit) was positive in 96% of GIST cases, while CD34 was positive in 84.6%, discovered on GIST-1(DOG1) in 46.2%, smooth muscle actin (SMA) in 26.9%, S100 in 19.2%, and desmin in 7.7%. In one CD117 negative patient, DOG1 was positive. Four patients had metastases (15.4%). The mean follow-up time was 56.5 ±36.2 month. The length of hospital stay was significantly longer in patients who had small intestinal GIST (p = 0.010). In immunohistochemical staining, SMA was significantly more common among spindle cell type (p = 0.032).ConclusionsGISTs are very rare tumors of the gastrointestinal tract, but the accurate diagnosis with immunohistochemical staining is vital for the treatment. So, large scale, prospective and randomized multicenter trials are needed to reduce the misdiagnosis rate of GISTs.