A New Method to Assess the Adequacy of Trucut Core Biopsy Specimens

Abstract

Aim: We sought to develop a simple touch prep method for evaluating trucut core biopsy (TCB) specimens that can be used during EUS to determine specimen adequacy and preliminary diagnoses. Methods: We performed 40 ex-vivo TCBs of fresh surgical specimens under direct visual guidance with the 19 guage Quick-Core needle (Wilson-Cook). A touch-prep was then made using one of four methods: 1) touching the biopsy lightly twice to a glass slide while keeping the specimen on the needle (“touch”), 2) pushing the biopsy 3cm along a slide while keeping the tissue on the needle (“push”), 3) dragging the specimen 3cm along the slide while keeping the tissue on the needle (“drag”), and 4) rolling the specimen 2cm along the slide after removing it from the needle with a toothpick (“roll”). Slides were stained with a Diff-Quik stain and biopsies were processed for histology. For each organ biopsied, the sequence of touch prep method was “touch”, “roll”, “push”, and “drag”. Ease of touch prep was rated on a Likert-type scale (1=easy, 5=cumbersome). Biopsy length and fragmentation were documented. Slides were blindly classified as malignant, suspicious, atypical, benign, or inadequate. Results: TCBs were taken of two normal stomachs, two ampullary adenocarcinomas, a normal pancreas, a thyroid adenoma, a uterine leiomyoma, a colon adenocarcinoma, a lung adenocarcinoma, and a lung metastasis of transitional cell carcinoma. Touch prep ease, adequacy, and accuracy are shown in the table. Cytologic interpretation could be made in 34/40 (85%) cases and was correct in 25/34 (74%) cases. Histologic interpretation could be made in 39/40 (98%) cases and was correct in 32/39 (82%) cases. Fragmentation (45% of biopsies) was not associated with a correct cytologic (p=0.7) or histologic (p=0.1) diagnosis. Biopsy length (median 10mm) was not associated with a correct cytologic (p=0.19) or histologic (p=0.96) diagnosis. Conclusions: Touch preps can be made with TCB samples and can predict specimen adequacy and diagnosis. The “touch” method was significantly easier than three other tested methods.