A retroperitoneal mass confirmed as a pancreatic adenosquamous carcinoma by endoscopic ultrasound-guided fine-needle aspiration

Adenosquamous carcinoma is a rare subtype of pancreatic adenocarcinoma, accounting for less than 4 % of all exocrine pancreatic malignancies and representing a ductal adenocarcinoma mixed with at least 30 % of malignant squamous cells [1] [2] [3]. Herein, we report a patient with a retroperitoneal mass in whom endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and immunohistochemical evaluation confirmed a pancreatic adenosquamous...