nodular parenchymal pattern is a vague way of saying dense lumpy breast tissue. It's not a sign of anything to worry about.
Dear kat1950, BI-RAD scale is used be radiologists in an attempt to standardize the readings of a mammogram, and help to determine what findings need to be followed up on. The scale goes from 1-5 with 1 being Negative (nothing to comment on), 5 being Highly suggestive of malignancy. Your reading 2 is a benign finding (a definitely benign finding. Recommendation is routine screening). Nodular parenchymal pattern, is a description of what your breast tissue looks like, and has not changed. Based on the report the recommendation would be to continue with routine screening, no further evaluation is necessary at this time. You would follow up with your doctor sooner if breast changes occur that concern you, for example, a new lump.