Sa1446 “Touch Preparation” of Jumbo Forceps Biopsies Allows Rapid Adequacy Assessment of Subepithelial Gastrointestinal Masses

Abstract

Although tunnel biopsies using jumbo forceps are useful in evaluating subepithelial masses (SEM), a limitation is the lack of immediate assessment of tissue adequacy. A potential solution is the use of on-site “touch preparation” cytology (TPC) analysis of these biopsy specimens. Our institutional endoscopic database was reviewed for patients who underwent EUS for SEM over a 15-month period. Patients who underwent forceps biopsies with TPC evaluation were indentified. After EUS characterization of the SEM, biopsies were preformed with a Radial Jaw 4 jumbo biopsy forceps (Boston Scientific Corp.) using a standard upper endoscope. Tunnel biopsies were performed until the mass was visualized. A biopsy was then obtained and TPC was performed with the remainder of the tissue submitted in saline. The slide was assessed for adequacy by the cytology staff and attending physician. If inadequate, further biopsies were performed in a similar manner. Forceps biopsies were only performed in endoscopically visible lesions. In select cases, fine needle aspiration (FNA) and core needle biopsy were also performed. Over a 15-month period, jumbo forceps biopsies with TPC were performed on 22 SEMs in 20 total patients. Mean EUS lesion size was 2.6 cm (range 0.9-10.5 cm). In 18 (81.8%) SEMs, TPC was adequate and final histology diagnostic. In 2 (9.1%) SEMs, both TPC and final histology were inadequate. Thus, TPC and final histology were concordant in 20/22 (91.0%) cases. In a single spindle cell neoplasm, tissue obtained on TPC was evaluated as adequate, but cells were insufficient for c-kit staining. In 1 additional SEM, TPC was erroneously reported as adequate with final pathology inadequate (schwannoma at surgery). GISTs (n=12), leiomyoma (n=2), and carcinoids (n=2) were the most common final histologic diagnosis. In 2 SEMs in which needle core biopsy was attempted, tissue was insufficient. TPC and final histology were adequate for both. FNA was attempted in 7 SEMs and performed in 6 (0-3 FNA passes). On-site cytology was nondiagnostic in 4 patients who underwent FNA. TPC and final histology were positive in 4/5 of the patients with failed or nondiagnostic FNA and 6/7 patients overall. TPC using jumbo forceps specimens provided an accurate assessment of tissue adequacy in addition to a preliminary diagnosis in the majority of SEMs. It may also serve as an alternative in procedures with insufficient FNA or needle core biopsy. In patients with endoscopically visible SEMs, “touch preparation” of jumbo forceps biopsies should be considered to ensure tissue adequacy prior to procedure termination.Tabled 1Definitive Diagnosis (n=18)No Definitive Diagnosis (n=4)TPC Adequate182TPC Inadequate02 Open table in a new tab