His primary areas of study are Surgery, Pancreaticoduodenectomy, Pancreatic disease, Internal medicine and Adenocarcinoma. His work deals with themes such as Multivariate analysis and Intraductal papillary mucinous neoplasm, which intersect with Surgery. The Pancreaticoduodenectomy study combines topics in areas such as Resection margin, Gastric emptying, Pancreatic cancer and Hazard ratio, Confidence interval.

As a part of the same scientific family, he mostly works in the field of Pancreatic disease, focusing on Pancreatitis and, on occasion, Pathology, High morbidity and Intensive care medicine. His study in Internal medicine is interdisciplinary in nature, drawing from both Gastroenterology and Oncology. The various areas that Michael B. Farnell examines in his Adenocarcinoma study include Radiation therapy and Pancreas.