Ovarian carcinoma in patients with endometriosis: MR imaging findings.
OBJECTIVE
Various types of malignancy can develop in patients with endometriosis. Enhancing mural nodules have been reported as an imaging characteristic of malignant transformations. We evaluated contrast-enhanced MR imaging to determine the optimum sequence to reveal mural nodules and other characteristics of malignant transformations.


METHODS
We examined 10 patients with pathologically proven ovarian adenocarcinoma in endometriosis and 10 patients (the control group) with ovarian endometrioma suggestive of malignant transformation on the basis of sonographic findings. We analyzed the size and nature of the endometriomas in each patient. We compared four types of contrast-enhanced MR imaging to determine which sequence best revealed mural nodules.


RESULTS
In the malignant and control groups, 80% of the cysts with findings suggestive of malignant transformation showed unilateral disease or larger endometrial cysts on the suggestive side than on the contralateral side. High signal intensity on T1-weighted images and low signal intensity on T2-weighted images relative to the myometrium were observed only in two of 10 malignant endometrial cysts and in all control cysts. All malignant endometriomas had small mural nodules with low signal intensity on T1-weighted contrast-enhanced images. Only three benign endometriomas had mural nodules and none of them enhanced. The enhancement of mural nodules was easily seen on dynamic subtraction imaging.


CONCLUSIONS
On the basis of our findings, endometrial cysts with malignant transformation rarely show low signal intensity on T2-weighted images and usually have enhancing mural nodules. Because the enhancement of mural nodules is often difficult to evaluate on conventional T1-weighted images, dynamic subtraction imaging can be valuable.
Tanaka
Y O
YO
Department of Radiology, Institute of Clinical Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
Yoshizako
T
T
Nishida
M
M
Yamaguchi
M
M
Sugimura
K
K
Itai
Y
Y
D000230:Adenocarcinoma / Q000150:complications* / Q000175:diagnosis; D018262:Adenocarcinoma, Clear Cell / Q000150:complications / Q000175:diagnosis; D000328:Adult; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D003287:Contrast Media; D004715:Endometriosis / Q000150:complications* / Q000000981:diagnostic imaging; D004717:Endometrium / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009215:Myometrium / Q000473:pathology; D010048:Ovarian Cysts / Q000150:complications / Q000175:diagnosis; D010049:Ovarian Diseases / Q000150:complications / Q000000981:diagnostic imaging; D010051:Ovarian Neoplasms / Q000150:complications* / Q000175:diagnosis; D013382:Subtraction Technique; D014463:Ultrasonography
D003287:Contrast Media; D019786:Gadolinium DTPA