Presentation
Cough for 2 days; chest pain on coughing. No hormonal symptoms.
Patient Data
Left lobe of liver elongated between spleen and left hemidiaphragm: beaver tail liver.
Oval lesion (1 cm) of macroscopic fat density (-78 HU) at anterior limb of right adrenal gland: myelolipoma.
Large triangular pads of fat density at both pericardiophrenic angles: pericardial fat pads.
Enlarged mediastinal lymph nodes at right lower paratracheal (4R), subaortic (5) and para-aortic (6) stations.
Case Discussion
Presence of true/macroscopic fat density (-30 to -90 HU) in an adrenal mass is diagnostic of myelolipoma, and no further workup is required. In the present case, the adrenal mass has densities close to -80 HU.
Nonetheless, the first differential for adrenal masses is adenoma, 80% of which are lipid-rich. CT densities of lipid-rich adrenal adenomas range around -15 HU.
Beaver tail liver is a normal anatomic variant. Its only major implication is that it may be more prone to injury by blunt abdominal trauma than the rest of the liver.