What is your diagnosis?

A 68-year-old woman with a history of pulmonary sarcoidosis, chronic lymphocytic thyroiditis, hyperlipidemia, and osteopenia was evaluated for elevated liver enzymes. Liver enzymes were found to be elevated 7 months earlier. Routine laboratory tests showed aspartate aminotransferase of 57 U/L (upper limit, 39 U/L), alanine aminotransferase of 54 U/L (upper limit, 52 U/L), alkaline phosphatase of 175 U/L (upper limit, 117 U/L), and total bilirubin of 0.5 mg/dL (upper limit, 1.3 mg/dL). She was on prednisone 5 mg/d, methotrexate 17.5 mg/wk, and atorvastatin 40 mg/d. Methotrexate and atorvastatin were stopped and prednisone increased to 10 mg/d.
Two months later, repeat laboratory tests showed aspartate aminotransferase of 213 U/L, alanine aminotransferase of 93 U/L, alkaline phosphatase of 1,472 U/L, and total bilirubin of 6.0 mg/dL. The initial ultrasound scan was normal. On further assessment, she complained of malaise, weight loss, shortness of breath, dry eyes, dry mouth, and insomnia. She denied any significant alcohol use. No new medications or supplements were started recently. Vital signs were normal. Physical examination was unremarkable. Viral hepatitis serologies were negative. Antinuclear antibody, anti-smooth muscle antibody, and antimitochondrial antibody were negative. She had a magnetic resonance cholangiopancreatography, which showed splenomegaly but was otherwise unremarkable. She had a liver biopsy (Figure A), which showed non-necrotizing granulomas (yellow arrows) with a chronic inflammatory lymphocytic infiltrate.
Given these findings, prednisone was increased to 20 mg. In the interim, the patient was admitted with acute acalculous cholecystitis. She had a laparoscopic cholecystectomy and an intraoperative liver biopsy. She developed respiratory failure postoperatively and was transferred to intensive care. Stress dose steroids and antibiotics were initiated. Laboratory tests showed a white blood cell count of 13.8 × 109/L, hemoglobin of 9.4 g/dL, platelets at 223 × 109/L, aspartate aminotransferase of 97 U/L, alanine aminotransferase of 63 U/L, alkaline phosphatase of 1,607 U/L, total bilirubin of 5.8 mg/dL (direct 3.3), and albumin of 2.4 g/dL. Pathology from the gallbladder (Figure B) and the intraoperative liver biopsy (Figure C) showed cells pathognomonic for the condition (green arrows).

On the basis of these findings, what is the final diagnosis?