There is an old adage in medicine that says “When you hear hoof beats, think horses. Don’t think zebras.” This phrase can be applied to every patient and case; your eyes don’t tell the whole story. It is usually good advice to confirm the obvious, rather than spending time and resources investigating rare things. Consider the virtue of the “differential diagnosis”. In medicine, the differential diagnosis is a process by which the consideration of diagnosing one disease is distinguished fr...