Ovarian torsion refers to rotation of the ovary and portion of the fallopian tube on the supplying vascular pedicle. 

It can result in venous, arterial and lymphatic stasis. It is a gynecological emergency and requires urgent surgical intervention to prevent ovarian necrosis. 

Ovarian torsion occurs due to two main reasons

• hypermobility of the ovary
• ovarian cyst or mass such as this case induced by corpus luteum cyst