The comma after "ultrasound" in the sentence "Palpable breast mass > 30 y.o. woman → do mammogram OR ultrasound, and core needle biopsy to exclude cancer" is important for clarity and to indicate that there are two distinct actions being recommended:
1. "do mammogram OR ultrasound"
2. "core needle biopsy to exclude cancer"
The comma separates these two actions, making it clear that they are separate steps in the diagnostic process. Without the comma, the sentence might be interpreted as "do mammogram OR ultrasound and core needle biopsy," which could lead to confusion about whether the biopsy should be performed after both mammogram and ultrasound or after just one of them. The comma helps avoid ambiguity and ensures the correct interpretation of the sentence.
