A 25-year-old woman presented to her primary care physician for evaluation of abdominal pain. Her discomfort had begun 6 months earlier and was localized to the right upper quadrant of the abdomen. She described a constant pressure unrelated to food intake that was associated with intermittent nausea and vomiting. She reported no change in urine or stools and no hematochezia, melena, dysphagia, anorexia, increase in abdominal girth, early satiety, or change in weight. She also had no lethargy, fatigue, pruritus, jaundice, night sweats, fever, easy bruising, or bleeding.
The patient's medical history was notable for type 1 diabetes mellitus, which had been diagnosed in childhood and was complicated by several episodes of diabetic ketoacidosis, hypothyroidism, psoriasis, and a seizure disorder, as well as juvenile rheumatoid arthritis, which was diagnosed when she was 18 months of age, after the development of arthritis in her right ankle and uveitis in both eyes. Her growth was normal despite eventual involvement of arthritis in both ankles and knees. She had been treated with naproxen, methotrexate, and glucocorticoids. Her current medications included carbamazepine, methotrexate, levothyroxine, and insulin. Her cumulative dose of methotrexate was 1.3 g. She reported no use of over-the-counter medications or herbal supplements. She worked as a nurse, was unmarried, and had no children. She smoked seven cigarettes a day and had done so for 10 years. She said she did not use alcohol or illicit drugs and had no history of blood transfusions, no occupational exposure to blood, and no tattoos. She was not sexually active and had no history of sexually transmitted infections. There was no family history of diabetes, arthritis, autoimmune diseases, or liver disease.
What whould you do next, and what is your differential diagnosis