Diagnostic yield of EUS-FNA for gastroduodenal submucosal tumors (SMTs)

Background and aim:

It's difficult to diagnose the etiology of submucosal tumors (SMTs) by radiological or endoscopic images alone, and therefore we used EUS-FNA to obtain a pathological diagnosis. The aim of this retrospective study was to evaluate the diagnostic yield of EUS-FNA for gastroduodenal SMTs, the frequency of adequate specimens for pathological evaluation, and to compare the results with post-surgical specimens.

Methods:

We included 155 consecutive patients (Male/Female=74/81) with gastroduodenal SMTs, who underwent EUS-FNA at Aichi Cancer Center Hospital, Nagoya, Japan, between January 2002 and December 2008. All SMTs were <5cm in size. The median age of patients was 58.4 years. Immunohistochemical staining with KIT, CD34, Actin, and S-100 antibodies was performed in addition to Hematoxylin-Eosin staining, in both EUS-FNA and resected specimens.

Results:

The location of the SMTs was in the upper stomach in 52.2%, middle stomach in 20.0%, lower stomach in 21.3%, and duodenum in 6.4% cases. Mean tumor size was 23.0±10.4mm (6–49mm). 57% of tumors were <2cm in diameter. Adequate specimen by EUS-FNA was obtained from 126 (81%) SMTs, and were diagnosed as: Gastrointestinal stromal tumors (n=50), Leiomyomas (n=18), Shwannomas (n=3), spindle cell tumors (unclassifiable mesenchymal tumors, n=29), malignant tumors (gastric cancers etc., n=12), and benign tumors (ectopic pancreas etc., n=14). 75 lesions were resected, and the concordance rate between EUS-FNA and resected specimen was 86.6% (65 cases). There were no severe procedure-related complications.

Conclusion:

EUS-FNA is an effective and accurate method for diagnosis of gastroduodenal SMTs less than 5cm.