Gastritis w/ Gastroesophageal junction nodule

I'm a 52 year old female with a family history of stomach cancer (paternal grandmother) and colon cancer (father). My history has been diagnosed with GERD, hiatal hernia and chronic gastritis of the antrum. I have just had my routine endoscopy w/colonoscopy and a gastroesophageal nodule was found. My physician said it appears to look normal but biopsy was taken. She gave me Nexium to take on a regular basis. My question is: What could have caused this nodule and so nodules of this sort tend to be benign or malignant? Also, what could be the cause of chronic gastritis and is the nexium the right med? thank You