noun
Refers to the medical specialty as a field of study or academic subject, distinct from a surgical operation (手術).
彼は大学で外科学を専攻している。
He is majoring in surgery at university.
外科学の進歩は目覚ましい。
Advances in surgery are remarkable.
外科 is the general term for surgery or a surgical department, whereas 外科学 specifically denotes the academic field.
Compound of 外科 (surgery) and 学 (study, -ology).