How can you distinguish between a benign and malignant breast mass?

Guessing: Guessing about whether a breast mass is malignant or benign is kind of like playing Russian Roulette. That is why a medical evaluation is warranted for any breast mass.

Clinical: evaluation and imaging studies(mammogram, ultrasound, MRI) help assess whether a mass needs biopsy for definitive diagnosis. Sometimes certain imaging features are specific for a benign cause(for example hamartoma, calcified fibroadenoma, or oil cyst). Other times, imaging features can estimate the probability of malignancy and help indicate what follow-up is needed.