The differential of a spontaneous hemoperitoneum in a young female is between ruptured corpus luteum cyst or ruptured ectopic pregnancy, with the beta HCG test being an important differentiator as they can look identical on imaging studies. At surgery, a ruptured corpus luteum cyst was confirmed.

HISTOLOGY REPORT

Clinical history: Bleeding right ovarian cyst. Right salpingo-oophorectomy.

Macroscopic description: Right ovary and Fallopian tube. Ovary 49x35x12mm and contains ruptured cystic area 25x20mm. Attached Fallopian tube 50x5x5mm

Microscopic description: The ovary contains an enlarged, degenerate corpus luteum, amounting to a luteal cyst. The background ovary and Fallopian tube are unremarkable.

Conclusion: Right ovary and Fallopian tube - luteal cyst