Sex cord tumor with annular tubules is a rare ovarian neoplasm that accounts for <6% sex cord stromal tumors 
. It is seen mostly in reproductive period and less commonly in pediatric population 
. One-third of cases are associated with hyperestrogenism and Peutz- Jegher’s syndrome.
Case report: A 26 years old unmarried girl came in gynaecology OPD with pain abdomen and abdominal lump since 4 months. After necessary investigations, she was planned for elective surgery but was lost to follow-up then. After 2 months, she presented in emergency with acute pain abdomen with shock. On examination, abdominopelvic mass was felt palpable corresponding to 20 weeks. Exploratory laparotomy with left sided salpingo-oopherectomy was performed. Hemoperitoneum of around 2 litres and a left-sided ovarian tumor 15x10cm in size with necrosis, hemorrhage and ruptured capsule was found. On histopathology report it was confirmed to be as sex cord tumor with annular tubules (SCTAT).
Conclusion: We describe for the first time to the best of our literature search the incidental detection of SCTAT in a patient previously thought to be case of germ cell tumor. Meticulous histological staining and awareness is required for detection of such unusual incidental lesions.