Diagnostic Significance of Endoscopic Ultrasonography in Patients with Lower Gastrointestinal Submucosal Tumors

Objectives: The aim of this study was to evaluate the diagnostic significance of endoscopic ultrasonography (EUS) in patients with lower gastrointestinal submucosal tumors. Methods: Study subjects were 33 lesions of submucosal tumor in the lower gastrointestinal tract examined by EUS. All lesions were also diagnosed histopathologically by endoscopic biopsy, endoscopic polypectomy, or surgical operation. We examined the internal echo levels and echo patterns, as well as the sites of tumors in the intestinal wall by EUS. Results: 1) Lower gastrointestinal submucosal tumors included 9 malignant lymphomas, 9 lipomas, 5 gastrointestinal stromal tumors or leiomyomas, 5 mucoceles of the appendix, 3 lymphangiomas, and 2 granular cell tumors. 2) Six malignant lymphomas (67%) involved all layers of the intestinal wall. The internal echo was hypoechoic to isoechoic, with a homogeneous pattern. 3) All lipomas were present in the third layer (submucosa). Eight lipomas (89%) had a hyperechoic internal echo, with a homogeneous pattern. 4) As for gastrointestinal stromal tumors or leiomyomas, 4 lesions (80%) were seen mainly in the fourth layer (muscularis propria). The internal echo was hypoechoic in all lesions. Four (80%) of these lesions showed punctual or macular hyperechoic patterns. 5) Most mucoceles of the appendix involved mainly the third layer. The internal echo was hypoechoic to isoechoic. Four (80%) of these lesions showed punctual or macular hyperechoic patterns. 6) All lymphangiomas were situated mainly in the third layer. The internal echo was anechoic, with septums. 7) Granular cell tumors were seen mainly in the third layer. The internal echo was hypoechoic. Conclusions: EUS may be useful for the qualitative assessments of lower gastrointestinal submucosal tumors, as well as the evaluation of tumor location in the intestinal wall.