Usefulness of endoscopic ultrasonography in the preoperative diagnosis of submucosal digestive tumours.

INTRODUCTION: The preoperative diagnosis of submucosal lesions in the gut may be complicated. Conventional endoscopy does not allow to clearly establishing a diagnosis, and does not adequately assess lesion size. Furthermore, endoscopic biopsy is usually not diagnostic. Cytology as performed by means of fine-needle puncture does not have enough sensitivity and specificity to be considered the gold standard in the diagnosis of these lesions. We will now assess the usefulness of endoscopic ultrasonography in the study of submucosal digestive tumors. MATERIALS AND METHODS: We have prospectively collected ultrasonographic studies from all the patients with submucosal tumors who were treated surgically. We assessed the sensitivity and specificity of this technique in the diagnosis of malignancy in said lesions, alongside factors that predict malignant behavior with the highest reliability. We also valued the reliability of ultrasound endoscopy in the assessment of lesion size and the wall layer where lesions are located. The results of histological studies were considered the gold standard. RESULTS: The average size of lesions as measured by ultrasound endoscopy was 37.42 mm, with no significant differences in surgical piece: 38.98 (p = 0.143). However, conventional endoscopy underestimates the size of lesions. Endoscopic ultrasonography was able to adequately establish the origin layer of lesions in all cases. Sensitivity, specificity, positive predictive value, and negative predictive value of ultrasound endoscopy in the diagnosis of malignancy were 89.5, 90.9, 89.5, and 90.9%, respectively. In the univariate analysis, the ultrasonographic characteristics associated with a diagnosis of malignancy included presence of ulceration (p = 0.043), size above 4 cm (p = 0.049), irregular edges of lesion (p = 0.0001), a heterogeneous ultrasonographic pattern (p = 0.002), and the presence of cystic areas above 2 mm (p = 0.012). In the multivariate analysis, the last three factors were considered independent predictive factors for malignancy. CONCLUSIONS: Endoscopic ultrasonography has a great sensitivity and specificity in the diagnosis of malignancy regarding submucosal lesions. The irregularity of lesion borders, a heterogeneous ultrasonographic pattern, and the presence of cystic areas above 2 mm in size were considered independent predictive factors for malignancy.