Ruptured mature cystic ovarian teratoma

Case contributed by Dr Owen Kang


Sudden onset acute abdominal pain, with clinical features of peritonism.

Patient Data

Age: 50 years
Gender: Female

In the midline, there is a large bilobed, heterogeneously hyperechoic mass which measures 65 x 57 x 55 mm in maximal dimensions consistent with the known mature cystic ovarian teratoma. Free fluid is demonstrated in the pouch of Douglas and right adnexa.
The appendix measures 5.5 mm and is not significantly hyperemic. Sonographic appearances are not convincing for appendicitis.

There is a bilobed fat containing heterogeneous mass in the pelvis posterior to the uterus, with amorphous calcific foci within it. Within its lower moiety a tooth is simulated. The appearances are consistent with a mature cystic teratoma. Minimal free fluid is demonstrated in the pouch of Douglas.
Furthermore, there is intraperitoneal fat density material similar to that within the pelvic tumor, insinuating in the pelvis, overlying the urinary bladder, extending cephalad over the right iliac fossa reaching the hepatorenal recess and forming a shallow accumulation of the surface of the right liver. The appearances are concerning for intraperitoneal rupture of the cystic teratoma.

The appendix is mildly distended, and there is minimal periappendiceal fat stranding and free fluid. An appendicolith is identified at the appendix ostium. There are a few enlarged lymph nodes in right iliac fossa. All these findings are suggestive of acute appendicitis.

Case Discussion

Upon surgical exploration, a ruptured mature cystic ovarian teratoma was confirmed to be the diagnosis.

Rupture is an uncommon, but known complication of mature cystic ovarian teratoma. On CT, the best clue is fat density within the peritoneal spaces and can be quite subtle. In this case, an abnormal appearing appendix, mimicking equivocal acute appendicitis was also present, but confirmed to be normal surgically.

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Case information

rID: 64640
Published: 4th Dec 2018
Last edited: 14th Aug 2019
System: Gynaecology
Inclusion in quiz mode: Included

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