Could Duodenal Mass Near Pancreas Be Malignant?

I just had an upper endoscopy and they found erythematous mucosa in the antrum and a duodenal mass near the pancreas which is hidden. The Doctor has order a CT scan and I have lost sixteen pounds in the last year and a half- representing almost 13 of my body weight. How serious could this be? The physician mentioned a possibility of lymphoma. My mother is currently dying of lymphoma and I was also wondering if this increases the likely hood of my having it as well.