[385] Comparative Study for Diagnosis of Gastrointestinal Submucosal Lesions (GISML) Using Standard EUS-Fine Needle Aspiration (FNA) Versus EUS-Fine Needle Biopsy (FNB)

Patricia Jimenez, Abu-Suboh Abadia Monder, Margarita Alberola, Maria Carme Dinares, Carmela Iglesias, Joan Dot, Ana Benages, Santiago Ramon-y-Cajal, Natalia Tallada. Vall Hebron Hospital, Barcelona, Spain

Background: GISML are difficult to diagnose with EUS-FNA (sensitivity: 61-91%; specificity: 61-100%). The mesenchymal nature of most of these lesions makes it difficult to obtain reliable samples for cytological diagnosis with the standard FNA needle. A new EUS-guided biopsy needle with side fenestration (ProCore) was developed to enable EUS-FNB. Our aim was to compare results using the standard FNA 19G needle with those using the new FNB 19G device (ProCore).
Design: 20 consecutive patients who underwent EUS for evaluation of GISML were enrolled in a pilot study (June 2011-February 2012), using the standard 19G FNA needle and the new 19G FNB ProCore device. Previous radiological diagnoses were: 9 GISTs, 6 leiomyomas, 3 lipomas and 2 heterotopic pancreas. For every case, FNA and FNB with on-site-evaluation (OSE) were performed (1-3 passes each). For all cases, FNA smears and touch preps of FNB were obtained; cell blocks (CB) from FNA were available in 13/20 and tissue core (TC) from FNB in 20/20. IHC was performed when appropriate.
Results: Size of GISML was 25 ± 14 mm (mean ± SD). 5 were located in the oesophagus, 12 in gastric camera, 3 in duodenum. Cytological diagnosis with FNA was possible for 6/20 patients, and for 4/20 with FNB. Histological diagnosis was possible for 6/13 CB (FNA) and for 9/20 TC (FNB). Combining cytology and histology from both devices, a total of 10/20 patients were diagnosed: 6 GISTs, 3 leiomyomas, and 1 neuroendocrine tumor (NET), confirmed by IHC stains and surgical biopsy. Remaining cases (10/20) were reported “unsatisfactory” with both needles. FNA was diagnostic for 8/20 patients and FNB for 9/20. Both devices were coincident in diagnosis for 7/20 patients. Of the remaining 3, 2 were diagnosed as leiomyoma by FNB and 1 as NET by FNA. Previous radiological diagnoses by EUS were confirmed in 9/10 cases (6 GISTs, 3 leiomyomas); NET was diagnosed as GIST by previous EUS.
Conclusions: Although diagnosis remains difficult in GISML, mostly of mesenchymal origin, FNB seems to have a slight advantage over FNA. With the same caliber, FNB provides superior tissue samples. Our results show an overall diagnostic yield of 50% for the combined technique of EUS-FNA-FNB with specificity of 100%. 7/10 lesions that remain undiagnosed had a size between 10-18 mm that could explain the low sensitivity in this series. In our experience, improvement in results can be achieved through choosing the appropriate device, and combining cytology, histology and OSE.
Category: Cytopathology

Monday, March 4, 2013 1:00 PM

Poster Session II # 69, Monday Afternoon

 

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