Case 306.

A 61-year-old woman was admitted to our institution to characterize an incidentally found mass in the porta hepatis. An episode of pulmonary embolism (18 months ago) and a pulmonary abscess (15 months ago) were reported. The patient had no history of known liver disease, previous cancer diagnosis, or trauma. She underwent total thyroidectomy for goiter several years ago, with initial iatrogenic hypothyroidism treated with levo-thyroxine hormone replacement therapy. During follow-up, this therapy was adjusted (50 µg per day) to induce euthyroidism and to achieve a target serum thyroid-stimulating hormone concentration of 1-2 mIU/L. Physical examination findings were unremarkable. Admission laboratory data were entirely normal, including tumor markers, such as carcinoembryonic antigen and carbohydrate antigen 19-9. Unenhanced (Fig 1) and multiphasic contrast-enhanced CT imaging was performed in arterial (Fig 2A), portal venous (Fig 2B), and delayed (3 minutes after injection) (Fig 2C) phases. Axial and coronal maximum intensity projection reconstructed CT images were obtained in the arterial (Fig 3) and portal venous (Fig 4) phases. Because of the imaging findings of the mass in the porta hepatis and concerns about malignancy, the patient underwent endoscopy. Therefore, endoscopic US-guided fine-needle biopsy was performed in the same session. The patient also underwent whole-body iodine 131 scintigraphy (Fig 5).