Mature cystic ovarian teratoma

Case contributed by Dr Adam Krajewski


Abdominal pain, nausea and vomiting.

Patient Data

Age: 40 years
Gender: Female

Cystic mass within the pelvis arising from the right adnexa with a fat fluid level measures 18 x 17 x 23 cm. Fatty contents measure -150 Hounsfield units. There is a soft tissue nodule centered at the fat-fluid interface of the cystic mass is consistent with a Rokitansky nodule (dermoid plug).

Large volume ascites with selective sparing of the bowel and mesentery and scalloping of the liver contour suggesting peritoneal carcinomatosis.

Annotated image

Ovarian cystic teratoma containing a fat fluid level and a Rokitansky nodule (dermoid plug) which has been described to resemble a "Poké Ball" as illustrated.

The patient underwent total abdominal hysterectomy, bilateral salpingo-oophorectomy and appendectomy.


Keratinizing moderately differentiated squamous cell carcinoma arising in an ovarian cystic teratoma/dermoid cyst. Involvement of ovarian surface, fallopian tube surface, uterus, pelvic peritoneum and appendix.

Case Discussion

  • malignant degeneration of mature ovarian cystic teratoma with a fat-fluid level and a Rokitansky nodule within the cyst lumen. The CT appearance is characteristic of a mature ovarian cystic teratoma
  • malignant transformation of ovarian teratomas occurs in 0.17-2% of cases 1,3
  • squamous cell carcinoma, as seen in this case, is the most common type of histology seen in malignant degeneration (80% of reported cases) 4
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Case information

rID: 77026
Published: 4th May 2020
Last edited: 3rd Jan 2021
System: Gynaecology
Inclusion in quiz mode: Included
Institution: Hartford Hospital