Tissue acquisition for comprehensive genomic profiling of gallbladder cancer using a forward-viewing echoendoscope in a patient who underwent Roux-en-Y reconstruction.

A 50-year-old man with a history of total gastrectomy, distal pancreatectomy, splenectomy, and Roux-en-Y reconstruction was admitted to our hospital with a gallbladder tumor that had infiltrated the liver and abdominal wall. Because malignant cells were not collected during the percutaneous biopsy, we planned to perform an endoscopic ultrasound-guided fine-needle biopsy with a 22-G Franseen needle using a forward-viewing echoendoscope. Using intermittent manual compression, the forward-viewing echoendoscope reached the duodenum under fluoroscopic guidance. Endoscopic ultrasound-guided fine-needle biopsy was performed using a 22-G needle and 20-mL syringe and yielded a sufficient specimen with a single puncture. Malignant cells were promptly identified during on-site evaluation. The composition of the specimen (> 20% cancer cells and tissue area exceeding 25 mm2) enabled comprehensive genomic profiling. Subsequently, high-tumor mutational burden was diagnosed based on comprehensive genomic profiling, and pembrolizumab was initiated as a second-line therapy. Even in cases involving Roux-en-Y reconstruction, endoscopic ultrasound-guided fine-needle biopsy using a forward-viewing echoendoscope can result in collection of a high-quality specimen.