A 78-year-old woman presented with palpitations and was diagnosed as having fast atrial fibrillation. On routine abdominal examination, a firm, mobile, nontender mass in the central abdomen was palpated. Abdominal computed tomography demonstrated a 10-cm-diameter, well-circumscribed lesion that was part solid and part cystic. It displaced small bowel loops and appeared to be intimately related to the inferior falciform ligament (Figure 1). Based on these findings, the patient underwent laparotomy via an upper midline incision. The mass (Figure 2) was identified and appeared to be attached to the inferior border of the liver. No other intra-abdominal abnormality was found and the mass was excised in toto. The patient made an uneventful recovery and was discharged home 4 days after surgery.