Journal of Ultrasound in Medicine, Vol 19, Issue 12 857-861, Copyright © 2000 by American Institute of Ultrasound in Medicine
Sonographic and clinical characteristics of struma ovarii
Y. Zalel, D. S. Seidman, M. Oren, R. Achiron, W. Gotlieb, S. Mashiach and M. Goldenberg
Department of Obstetrics and Gynecology, The Chaim Sheba Medical Center, Sackler School of Medicine, Tel Aviv University, Tel Hashomer, Israel.
Our objective was to evaluate the preoperative clinical, laboratory, and
sonographic characteristics of struma ovarii in comparison to ovarian
dermoid cysts. A retrospective review of gynecologic patients operated on
for mature cystic teratoma over a 10 year period identified 12 cases of
struma ovarii. These cases, combined with 4 additional cases from an
earlier report, were the subject of this study. Results were compared to 32
cases of ovarian dermoid cysts. Ovarian struma ovarii occurred in 12 (4.8%)
of 251 cases of ovarian dermoid cysts. Most patients were premenopausal,
and the mean lesion diameter was 57.3 mm (range, 30-95 mm). Struma ovarii
occurred more frequently (68.8%) in the right adnexa and was seen with a
normal CA-125 level. Blood flow, assessed by Doppler ultrasonography, was
located in the center of the lesion in all cases of struma ovarii. Rare
cases were seen with elevated tumor markers and low resistance blood flow.
With regard to dermoid cysts, blood flow had a higher resistive index. In
addition, no blood flow could be detected from the center of the echoic
lesion in dermoid cysts (P < 0.0001). In summary, it is difficult to
distinguish between struma ovarii and dermoid cysts on the basis of their
sonographic appearance. Nevertheless, Doppler flow may aid in the
preoperative diagnosis of struma ovarii. Blood flow signals, detected from
the center of the echoic lesion, and low resistance to flow may be more
common in struma ovarii.
