Female teenager with acute onset of right lower quadrant pain and nausea and vomiting

CT of ovarian cystadenoma
Coronal (above left), sagittal (above right) and axial (below) CT with contrast of the abdomen show a large, well circumscribed, homogenous, non-enhancing, fluid density mass that fills the width of the lower abdomen and pelvis and lies superior and separate from the bladder and uterus. Neither ovary was clearly identified.

The diagnosis was ovarian cystadenoma.