A 20 Year Retrospective Study Assessing the Percentage Distribution of Submucosal Lesions Along the Gastrointestinal Tract

Abstract

Introduction: We reviewed our experience in the evaluation of submucosal lesions (SML) to better define the incidence of each type of SML based upon their location and endoscopic appearance. Determining the percent of each SML at each section of the gastrointestinal tract may provide valuable information for the practicing endoscopist to enhance pre-test probability prior to referral for endoscopic ultrasound (EUS). Methods: We reviewed all referrals for endoscopic ultrasonographic evaluation for submucosal lesions (SML) from 1993 through 2013 at the University of Louisville. Of the total 4789 cases, 639 (13.3%) were referred for evaluation of SML by EUS. Of these patients referred, 369 (55.1%) were male with an average age of 58.49 (range 18-88 years). SMLs were distributed as follows: 122 Esophageal (18.7%), 353 gastric (54.1%), 105 small intestinal (16.1%), 36 colonic (5.5%), and 35 rectal (5.4%). Data was stratifi ed by location of the SML and by type (table 1/figure 1). Percentages were calculated for each SML at each gastrointestinal location. Hypoechoic lesions included c-kit CD-117 positive GISTs and negative leiomyomas. “Normal” was defined by studies where there was extrinsic compression of the GI tract by a normal organ or structure. “Other” lesions included hypertrophic folds, polyps, involuted appendices, ganglioneuromas, pancreatic rests and abscesses. Paired Pearson correlations were calculated for the different sections of the GI tract, comparing the distribution of types of SML from one section to the next.Figure 1Results: Overall, the incidence of each type of SML at a specific section of the GI tract differed significantly through the GI tract, meaning that contiguous and non-contiguous sections of GI tract had different proportions of each type of SMLs. The incidence of cysts and hypoechoic lesions both decreased when passing distally through the GI tract. In contrast, lipomas increased in incidence distally in passing the GI tract. Extrinsic compression made up a significant portion of cases referred for evaluation of SML (14.7%), with structures varying from one level of the GI tract to another (table 2).Table 1: Percent distribution of SMLs at Different Locations in the GI TractTable 2: Causes of External Compression Throughout the GI TractConclusion: At any level of GI tract, an assortment of other etiologies may create the appearance of true SMLs, such as extrinsic compression of GI tract by normal organs, polyps and hypertrophic mucosal folds. Based on results, location of a SML within the GI tract may help the endoscopist predict etiology of true SMLs prior to referral to EUS.