CASE 1209 Published on 30.07.2001

MRI appearance of an ovarian fibroma

Section

Genital (female) imaging

Case Type

Clinical Cases

Authors

JF. Deux, C. Balleyguier, E. Thibaud, O. Hélénon, Y. Menu

Patient

47 years, female

Categories

No Area of Interest ; Imaging Technique MR, MR, MR

No Procedure ; No Special Focus ;

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Clinical History

Pelvic pain with fast growing pelvic mass.

Imaging Findings

Frequent pelvic pain. Endovaginal ultrasonography revealed a 10 cm solid hypoechoic mass close to the uterus, with marked attenuation. Three months before, the mass was 3 cm smaller. Diagnosis between solid ovarian mass or pedunculated leiomyoma was not possible. MRI examination showed a 10 cm pelvic mass with well defined margins. On T2-weighted images the mass showed a heterogeneous signal with areas of high intensity. A well defined margin was seen between the mass and the uterus. On T1-weighted images the lesion showed a homogeneous signal. Fat-suppressed axial T1-weighted images obtained after gadolinium injection demonstrated extensive heterogeneous enhancement. There was a different enhancement between the mass and the uterus. Only the left ovary was visible. A large amount of peritoneal fluid was located in the pouch of Douglas. A primary ovarian lesion of gonadal stromal cell origin was considered: an ovarian fibroma or fibrothecoma were suggested because of the middle age of the patient, echographic appearance, well defined margin and signal intensity. Surgery confirmed the diagnosis of right ovarian fibroma.

Discussion

Fibromas and fibrothecomas are the most common solid primary tumors of the ovary, accounting for 4 % of all ovarian tumors. They are almost always benign and encountered in middle-aged women. These gonadal stroma cell origin tumors contain spindle cells, collagen, and theca cells for fibrothecomas. They may be associated with endometrial hyperplasia and endometrial polyps. Ascite or pleural effusions (Meig syndrome) may be present. At US these lesions are generally hypoechoic with posterior wall attenuation. Diagnosis between a pedonculated leiomyoma and an ovarian mass may be difficult. MR imaging allows differentiation between adnexal mass and leiomyoma. Usually, fibroma and fibrothecoma present as a solid mass, with well defined margins and a low signal intensity on T1 and T2 weighted images. These tumors may show areas of high signal intensity on T2 weighted images consistent with edema for small lesions (<6 cm) or cystic degeneration for larger ones. A band of T2 hypointensity separating the tumor from the uterus on all imaging planes is also characteristic. Gadolinium injection generally results in a heterogeneous enhancement but does not provide further information.

Differential Diagnosis List

Ovarian fibroma

Final Diagnosis

Ovarian fibroma

References

[1] Troiano RN, Lazzarini KM, Scoutt LM, Lange RC, Flynn SD, McCarthy S
Fibroma and fibrothecoma of the ovary: MR imaging findings.
Radiology 1997; 204(3):795-8. (PMID: 9280262)

[2] Schwartz RK, Levine D, Hatabu H, Edelman RR
Ovarian fibroma: findings by contrast-enhanced MRI
Abdom imaging 1997; 22(5):535-7. (PMID: 9233896)

[3] Outwater EK, Siegelman ES, Talerman A, Dunton C
Ovarian fibromas and cystadenofibromas: MRI features of the fibrous component.
J Magn Reson Imaging 1997; 7(3):465-71. (PMID: 9170028)

[4] Weinreb JC, Barkoff ND, Megibow A, Demopoulos R
The value of MR imaging in distinguishing leiomyomas from other solid pelvic masses when sonography is indeterminate.
Am J Roentgenol 1990; 154(2):295-9. (PMID: 2105017)

[5] Jeong YY, Outwater EK, Kang HK
Imaging evaluation of ovarian masses
Radiographics 2000; 20(5):1445-70. (PMID: 10992033)

Case information

URL:	https://eurorad.org/case/1209
DOI:	10.1594/EURORAD/CASE.1209
ISSN:	1563-4086

Figure 1

Axial T2-weighted image of the pelvis

Pelvic mass with well defined margin. Heterogeneous signal intensity of the lesion with high signal intensity areas. Note differences of signal intensity between mass and uterus.

Figure 2

Axial T2-weighted image of the pelvis

Left ovary is present between uterus and posterior wall of the bladder. Right ovary is not visible.

Figure 3

Sagital T2-weighted image of the pelvis

Heterogeneous anterior pelvic mass with sharp borders. The mass is distinct from uterus on sagital image. Peritoneal fluid was also present.

Figure 4

Axial T1-weighted image of the pelvis

Pelvic mass with homogeneous signal close to signal of the uterus.

Figure 5

Axial T1-weighted image after injection of Gadolinium

The mass showed an heterogeneous enhancement compared to myometrial enhancement, which allows the distinction between an ovarian mass and a uterin leiomyoma.