Gastro-intestinal stromal tumor (GIST) complicating a colonic interposition: a novel case report

Clinicopathological features and prognosis of colonic gastrointestinal stromal tumors: evaluation of a pooled case series

Background

Due to the extremely rare incidence, data about colonic GISTs are limited. Therefore, aim of the present study was to explore clinicopathological characteristics and prognosis of colonic GISTs.

Patients and Methods

Colonic GISTs cases were obtained from our center and from case report and clinical studies extracted from MEDLINE. Clinicopathological features and survivals were analyzed.

Results

There were 79 colonic GISTs patients with a female predominance. The median age was 66 years (range 0.17-84). The median tumor size was 5.8 cm (range 0.5-29). The most common location was sigmoid colon (45.8%), followed by transverse colon (19.5%). The majority of colonic GISTs were high risk (70.8%). Mitotic index was correlated with gender (P = 0.002) and tumor size (P = 0.005), and tumor location was correlated with age (P = 0.017). The five year DFS and DSS were 57.4% and 61.6%, respectively. Mitotic index and NIH risk classification were associated with prognosis of colonic GISTs. However, mitotic index was the only independent risk factor. The distribution of tumor size and NIH risk classification were significantly different between colonic and gastric GISTs (both P = 0.000). The DFS and DSS of colonic GISTs were significantly lower than that of gastric GISTs (P = 0.012 and P = 0.002, respectively).

Conclusions

The most common location for colonic GISTs was sigmoid colon. Most tumors were high risk. Mitotic index was the only independent risk factor for prognosis of colonic GISTs. Colonic GISTs differ significantly from gastric GISTs in respect to clinicopathological features. The prognosis of colonic GISTs was worse than that of gastric GISTs.

Capsule endoscopy in the diagnosis of an exophytic gastrointestinal stromal tumor in the small intestine of a young adult woman: A case report

Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors that mainly arise in the gastrointestinal tract. They are usually asymptomatic and are incidentally discovered during endoscopy or surgery. Diagnosis is confirmed by histological examination of the specimen. This is the case report of an asymptomatic GIST of the small intestine diagnosed by wireless capsule endoscopy. The tumor was initially suspected to be a leiomyoma, as GISTs in young adults are rare and are mainly discovered incidentally during colorectal cancer screening. The patient was a 35-year-old woman with occult gastrointestinal bleeding, with a normal medical history. An endoscopic assessment of the upper and lower GI tract (gastroscopy and colonoscopy) was performed, but did not reveal any abnormalities. Subsequently, an exophytic tumor initially suspected as leiomyoma or external pressure was detected in the small intestine by capsule endoscopy. A computed tomography scan was suggestive of a soft tissue tumor arising from the small intestine. A surgical specimen was obtained and the immunohistochemical examination revealed that the tumor was positive for CD117 and discovered on GIST-1 markers, while the markers of carcinoma, melanoma and lymphoma were negative, which was consistent with a diagnosis of a low-risk GIST with a mitotic count of <5/50 high-power fields. In this study, we aimed to present in detail the capsule endoscopic and radiological characteristics, as well as the findings of the histological examination of the surgical specimen. In conclusion, when occult blood is detected in the stool, even when gastroscopy and colonoscopy reveal no abnormal findings, small intestinal lesions should be suspected. Exophytic small intestinal GISTs, although rare, particularly in younger patients, they should be considered by physicians in the differential diagnosis of obscure GI bleeding of unknown origin, in order to reduce morbidity and mortality. Capsule endoscopy may be considered to be the first choice as a diagnostic tool for obscure GI bleeding.