Two cases of resectable pancreatic cancer diagnosed by open surgical biopsy after endoscopic ultrasound fine-needle aspiration failed to yield diagnosis: case reports

BACKGROUND Tumor biopsy for histological diagnosis is required preoperatively and before initiating chemotherapy or radiation therapy for patients with pancreatic cancer (Cancer of the Pancreas: Clinical Practice Guidelines, European Society for Medical Oncology). Endoscopic ultrasound fine-needle aspiration (EUS-FNA) is widely applied to obtain tissue samples for histological examination. However, in some cases, EUS-FNA cannot be performed safely or tissue samples are insufficient to establish a definitive diagnosis. We present two cases of pancreatic cancer diagnosed by open surgical biopsy after EUS-FNA failed to yield a diagnosis. CASE PRESENTATION Case 1 was a 50-year-old man. Computed tomography showed a hypovascular lesion in the uncus of the pancreas. Although EUS-FNA was conducted twice, we could not collect enough quantity of tissue samples to establish a definitive diagnosis. Open surgical biopsy revealed adenocarcinoma, and the patient underwent preoperative chemoradiation therapy followed by curative operation. Case 2 was a 68-year-old man. Computed tomography showed a hypovascular tumor in the uncus of the pancreas. EUS revealed a 14-mm hypoechoic lesion, but we could not perform EUS-FNA because the superior mesenteric vein was located in the puncture line. Open surgical biopsy revealed adenocarcinoma, and the patient underwent preoperative chemoradiation therapy followed by pancreaticoduodenectomy. CONCLUSIONS EUS-FNA is the first choice in the diagnostic modalities of pancreatic neoplasm, but open surgical biopsy is an effective diagnostic method if EUS-FNA is unsuccessful.