4543 Endoscopic ultrasound guided fine needle aspiration for the diagnosis of the gastrointestinal submucosal tumors.

Abstract

Objectives: Careful observation of EUS findings can be of assistance in predicting the histopathological nature of SMTs. However, an exact differentiation between benign and malignant SMTs by EUS alone is impossible. The aim of this study was to evaluate the efficacy of EUS and EUS FNA for the differential diagnosis of SMTs. Materials and Methods: From December 1994 to September 1999, EUS and EUS FNA using the Olympus curved linear array echoendoscope (XGF-UC3 and GF-UC4) were performed for 25 cases (10-200mm in size) resected for suspected malignant myogenic tumors by EUS or EUS FNA. The patients with suspected benign myogenic tumors by EUS and EUS FNA were followed up without operation. Final diagnosis of resected cases were leiomyosarcomas in 15 (high grade 6 and low grade 16), endocrine cell carcinoma, metastatic carcinoma and Glomus tumor each in one. Criteria for assessing myogenic tumor by EUS were as follows: a suspected malignancy ≥4cm or smaller < 4cm with cyst spaces; a suspected benign mass with regular borders, echo-homogeneity and measuring < 3cm. Results: The accuracy rate for EUS and EUS-guided FNA were 40% and 92%, respectively. EUS-FNA could also provide definitive diagnosis of 3 non-myogenic tumors. EUS Malignant Benign Indeterninate Malignant 15 4 5 Benign 0 0 1 Total 15 4 6 EUS FNA Malignant Benign Indeterminate Malignant 22# 0 1* Benign 1 1## 0 Total 23 1 1 *insufficient material #Carcinoid & metastatic carcinoma each in 1 ## Glomus tumor 1 Conclusion: EUS FNA is an effective modality to enhance the specificity of EUS diagnosis for suspected myogenic tumor.