A 22-year-old woman was admitted to this hospital because of hypercalcemia and a pelvic mass. One month before admission, abdominal pain developed, followed by abdominal fullness, anorexia, nausea, vomiting, polydipsia, and nocturia. A computed tomographic scan of the pelvis showed a complex right adnexal mass. The serum calcium level was 17.2 mg per deciliter. A diagnostic procedure was performed.