The mass was surgically removed from the left liver with clean margins. Surgery was the treatment of choice because of the slow-growing and expansive nature of this type of tumor, which does not tend to metastasize. It was essential to define the portal hilus in this case to define the resectability of the mass. Even though the mass was of considerable size, the portal hilus was impinged on, but not invaded, and enough right liver was available to the patient to continue to maintain metabolic needs. The US-guided biopsy defined the mass as a slowly growing cystadenoma that rendered surgery the correct method of therapy with a good prognosis. However, given the solitary nature of the lesion, direct biopsy after surgical resection would have been a viable option as well. The patient was lost to follow up.