A 62-year-old nulligravida woman presented with a 10-month history of progressive abdominal distension and diffuse abdominal pain associated with a 25-kg weight gain. Results of upper endoscopy and colonoscopy performed 1 week prior to presentation were normal. She reported dyspnea on exertion but had no fevers or chills, nausea or vomiting, hematochezia, or change in the caliber or consistency of her stools. On physical examination, she had normal vital signs, no abnormalities on pelvic and rectal examination, and a large abdominal mass extending from the epigastrium to the pelvis. Laboratory testing showed a normal complete blood cell count, erythrocyte sedimentation rate, and comprehensive metabolic panel and normal levels of serum carcinoembryonic antigen (CEA), cancer antigen 125 (CA-125), and cancer antigen 19-9 (CA19-9). Computed tomography (CT) of her chest, abdomen, and pelvis revealed a large mass occupying the entire abdominal cavity (Figure 1).