Benign non-GIST tumors may be distinguished from duodenal GIST as they are smaller in size. LR is a viable treatment option for suspected GIST involving the duodenum.

The NIH, modified NIH, and AFIP criteria are useful in the prognostication of GIST, and the AFIP risk criteria provided the best prognostication among the three systems for primary localized GIST. However, remarkable prognostic heterogeneity exists in the AFIP high-risk category, and with our proposed modification, this system provides the most accurate prognostic information.

The occurrence of true EGISTs is rare. Most cases demonstrate some form of communication or contact with the gut wall, and EGISTs are significantly larger than extramural or intra/transmural GIST. These observations suggest that most, if not all, cases of EGISTs are likely to represent mural GISTs with extensive extramural growth with eventual loss of contact with the muscle layer of the gut.

Intraabdominal schwannomas are rare tumors, which are most frequently located within the GIT. GIT schwannomas are difficult if not impossible to diagnose preoperatively as endoscopic and radiologic findings are nonspecific. The treatment of choice is complete surgical excision because of diagnostic uncertainty, and the long-term outcome is excellent as these lesions are uniformly benign.

SOAs and SMAs have similar clinicopathologic features. On the other hand, SOAs differ from MCNs by their relatively higher male/female ratio, higher frequency of tumors occurring in the head of the pancreas, and smaller cyst size. Knowledge of these distinguishing clinical features when used in combination with other diagnostic modalities such as endoscopic ultrasonography/fine-needle aspiration will enable clinicians to better differentiate these two pathologic entities preoperatively.