Introduction
Epidemiology
Etiopathogenesis
Classification
Primary tumours (95 %) | Surface epithelial-stromal tumours (65 %) | serous | benign | cystadenoma, papillarycystadenoma adenofibroma/cystadenofibroma |
borderline | papillary cystic tumour, surface papillary tumour, adenofibroma/cystadenofibroma | |||
malignant | adenocarcinoma, surfacepapillary adenocarcinoma, adenocarcinomafibroma | |||
mucinous | benign | cystadenoma, adenofibroma/cystadenofibroma | ||
borderline | intestinal type, endocervical-like | |||
malignant | adenocarcinoma, adenocarcinomafibroma | |||
endometrioid | ||||
clear cell | ||||
transitional cell (Brenner) | ||||
undifferentiated and unclassified | ||||
Germ cell tumours (15 %) | teratoma | biphasic or triphasic | mature | |
immature | ||||
monodermal | strumaovarii | |||
dysgerminoma | ||||
Yolk sac tumour | ||||
choriocarcinoma | ||||
embrionalcell carcinoma | ||||
Sex cord-stromal (10 %) | granulosa cell | adult | ||
juvenile | ||||
thecoma-fibroma group | fibroma | |||
techoma | ||||
sclerosing stromal tumour | ||||
unclassified (fibrothecoma) | ||||
Sertoli-Leydigcell | ||||
steroidcell | ||||
Miscellaneous (5 %) | small cell carcinoma, gestational choriocarcinoma, others | |||
Secondary tumours (5 %) | stomach, colon, breast, lung, contralateral ovary |
Staging
Stage I | Tumour confined to ovaries | |
I A | Tumour limited to 1 ovary, capsule intact, no tumour on surface, negative washings | |
I B | Tumour involves both ovaries otherwise like IA | |
I C | Tumour limited to 1 or both ovaries | |
I C1
| Surgical spill | |
I C2
| Capsule rupture before surgery or tumour on ovarian surface | |
I C3
| Malignant cells in the ascites or peritoneal washings | |
Stage II | Tumour involves 1 or both ovaries with pelvic extension (below the pelvic brim) or primary peritoneal cancer | |
II A | Extension and/or implant on uterus and/or Fallopian tubes | |
II B | Extension to other pelvic intraperitoneal tissues | |
Stage III | Tumour involves one or both ovaries with cytologically or histologically confirmed spread to the peritoneum outside the pelvis and/or metastasis to the retroperitoneal lymph nodes | |
III A | Positive retroperitoneal lymph nodes and /or microscopic metastasis beyond the pelvis | |
III A1
| Positive retroperitoneal lymph nodes only | |
III A2
| Microscopic, extrapelvic (above the brim) peritoneal involvement ± positive retroperitoneal lymph nodes | |
III B | Macroscopic, extrapelvic, peritoneal metastasis ≤2 cm ± positive retroperitoneal lymph nodes. Includes extension to capsule of liver/spleen | |
III C | Macroscopic, extrapelvic, peritoneal metastasis >2 cm ± positive retroperitoneal lymph nodes. Includes extension to capsule of liver/spleen | |
Stage IV | Distant metastasis excluding peritoneal metastasis | |
IV A | Pleural effusion with positive cytology | |
IV B | Hepatic and/or splenic parenchymal metastasis, metastasis to extraabdominal organs (including inguinal lymph nodes and lymph nodes outside of the abdominal cavity) |
Approach to adnexal masses
Serum markers
Diagnostic imaging
Our MR protocol
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Localizer sequence in the three spatial planes;
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axial T2-weighted single-shot fast spin-echo (SSFSE) sequence [time to repetition (TR)/time to echo (TE) range 765/59; flip angle 90°; section thickness 6 mm; interslice gap 0.6 mm; bandwidth 31.25 kHz; field of view (FOV) 38 cm; matrix 320 × 288; number of averages 0.54; number of images 30; acquisition time 24 s] used as second localiser to identify the longitudinal axis of the uterus in the case of laterally deviated uterus;
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sagittal T2-weighted fast spin-echo (FSE) sequence parallel to the longitudinal axis of the uterus (identified on the previous SSFSE sequence) (TR/TE range 4675/100; flip angle 90°; section thickness 4 mm; interslice gap 1 mm; bandwidth 41.67 kHz; FOV 32 cm; matrix 320 × 224; number of averages 4; number of images 26; acquisition time 3 min 49 s);
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oblique coronal T2-weighted FSE sequence parallel to the longitudinal axis of the uterus (TR/TE range 4675/100; flip angle 90°; section thickness 4 mm; interslice gap 1 mm; bandwidth 41.67 kHz; FOV 32 cm; matrix 320 × 224; number of averages 4; number of images 26; acquisition time 3 min 49 s);
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oblique axial T2-weighted FSE sequence perpendicular to the longitudinal axis of the uterus (TR/TE range 4675/100; flip angle 90°; section thickness 4 mm; interslice gap 1 mm; bandwidth 41.67 kHz; FOV 32 cm; matrix 320 × 224; number of averages 4; number of images 26; acquisition time 3 min 49 s);
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sagittal or axial oblique or coronal oblique fat suppressed T2-weighted FSE sequence (TR/TE range 4675/100; flip angle 90°; section thickness 4 mm; interslice gap 1 mm; bandwidth 41.67 kHz; FOV 32 cm; matrix 320 × 224; number of averages 4; number of images 24; acquisition time 3 min 49 s);
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axial T1-weighted gradient-echo (GRE) sequence in-out (chemical-shift imaging) (TR/TE 180/2,1; flip angle 80°; section thickness 6 mm; interslice gap 0,6 mm; bandwidth 62,5 kHz; field of view 38 cm; matrix 256 × 224; number of averages 1; number of images 20; acquisition time 22 s);
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axial DWI SE EPI (TR/TE 3000/74,1; flip angle 90°; section thickness 5 mm; interslice gap 1 mm; bandwidth 250 kHz; field of view 45 cm; matrix 160 × 160; number of averages 16; number of images 14; b-value 0 e 800 s/mm2; acquisition time 1 min e 40 s);
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sagittal, coronal oblique, axial oblique T1-weighted 3D gradient-echo liver acquisition with volume acquisition (LAVA) sequence with fat suppression (TRe/TE range 4.4/2.1; flip angle 12°; section thickness 3.4 mm; overlap locations −1.7 mm; bandwidth 62.5 kHz; FOV 40 cm; matrix 320 × 192; number of averages 0.75; number of images 104; acquisition time 22 s).
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dynamic sagittal T1-weighted 3D gradient-echo LAVA with fat suppression (TR/TE range 4.4/2.1; flip angle 12°; section thickness 3.4 mm; overlap locations −1.7 mm; bandwidth 62.5 kHz; FOV 40 cm; matrix 320 × 192; number of averages 0.75; number of images 104; acquisition time 22 s) acquired at 60 and 120 s after contrast administration;
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T1-weighted 3D gradient echo LAVA fat-suppressed sequence, in the coronal oblique (parallel to the longitudinal axis of the uterus), axial oblique (perpendicular to the longitudinal axis of the uterus) and axial planes (TR/TE range 4.4/2.1; flip angle 12°; section thickness 3.4 mm; overlap locations −1.7 mm; bandwidth 62.5 kHz; FOV 40 cm; matrix 320 × 192; number of averages 0.75; number of images 104; acquisition time 22 s).
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Standard three-plane scout image;
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coronal T2-weighted SSFSE with and without fat suppression (TR range/TE range 705/90; flip angle 90°; section thickness 6 mm; interslice gap 0.6 mm; bandwidth 83.33 kHz; field of view 44–48 cm; matrix 384 × 224; number of signals acquired 0.57; number of images 28; acquisition time 24 s);
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axial T2-weighted SSFSE with and without fat suppression [time to repetition (TR)/time to echo (TE) range 765/59; flip angle 90°; section thickness 6 mm; interslice gap 0.6 mm; bandwidth 31.25 kHz; field of view (FOV) 38 cm; matrix 320 × 288; number of averages 0.54; number of images 30; acquisition time 24 s];
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fast imaging employing steady-state acquisition (FIESTA) in the coronal, axial and sagittal planes (TR range/TE range 4/1.7; flip angle 75°; section thickness 6 mm; interslice gap 0.6 mm; bandwidth 100 kHz; field of view 44–48 cm; matrix 320 × 224; number of signals acquired 1; number of images 28; acquisition time 22 s);
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axial DWI SE EPI [TR range/TE range 3000/74; flip angle 90°; section thickness 8 mm; interslice gap 2 mm; field of view 42 cm; matrix 160 × 160; number of signals acquired 2; number of images 15; b-value 0 and 800 s/mm2 that represent the best compromise between signal to noise ratio (SNR) and lesion detection sensitivity on our MR system; ASSET 2; acquisition time 27 s];
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sagittal, axial and coronal T1-weighted 3D gradient echo LAVA fat-suppressed sequence (TR range/TE range 4.1/1.9; flip angle 12°; section thickness 3.4 mm; overlap locs −1.7 mm; bandwidth 62.5 kHz; field of view 44–48 cm; matrix 320 × 192; number of signals acquired 0.70; number of images 120; acquisition time 23 s).
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sagittal T1-weighted 3D gradient echo LAVA fat-suppressed sequence (TR range/TE range 4.1/1.9; flip angle 12°; section thickness 3.4 mm; overlap locs −1.7 mm; bandwidth 62.5 kHz; field of view 44–48 cm; matrix 320 × 192; number of signals acquired 0.70; number of images 120; acquisition time 23 s) acquired at 60 and 120 s after contrast administration;
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axial T1-weighted 3D gradient echo LAVA fat-suppressed sequence (TR range/TE range 4.2/2; flip angle 12°; section thickness 3.4 mm; overlap locs −1.7 mm; bandwidth 62.5 kHz; FOV 40 cm; matrix 320 × 192; number of signals acquired 0.70; number of images 120; acquisition time 23 s);
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coronal T1-weighted 3D gradient echo LAVA fat-suppressed sequence (TR range/TE range 4.1/1.9; flip angle 12°; section thickness 3.4 mm; overlap locs −1.7 mm; bandwidth 62.5 kHz; field of view 44–48 cm; matrix 320 × 192; number of signals acquired 0.70; number of images 120; acquisition time 23 s).
Imaging findings
Classification of adnexal masses basing on morphological appearance | ||
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Cystic unilocular (benign)
| non ovarian | paraovarian cysts, hydrosalpinx, pyosalpinx and hematosalpinx |
ovarian | functional cysts and serous cystadenomas (common) | |
cystadenofibromas and mucinous cystadenomas (less common) | ||
Cystic multilocular (benign and borderline)
| endometriomas, mucinous cystadenomas and borderline tumours (common) | |
serous cystadenomas (less common) | ||
Cystic and solid (benign, borderline and malignant)
| benign | mature cystic teratoma |
borderline to malignant | surface epithelial tumours, metastasis, Yolk sac, granulosa cell and Sertoli-Leydig tumours | |
Predominantly solid (benign, borderline and malignant)
| benign | Brenner tumour, fibrothecomas |
borderline to malignant | serous and mucinous carcinomas, dysgerminoma and Yolk sac tumour, granulosa and Sertoli-Leydig cell tumours, metastasis |
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unilocular cyst;
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multilocular cyst;
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cystic and solid;
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predominantly solid.
Group | Lesion | Findings | T2 | T1 | Gd-T1 | Mean age |
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Cystic unilocular | Functional cysts | follicles (diameter <20 mm), dominant follicles (diameter 20–25 mm), follicular cysts, corpus luteum cysts. | high | low corpus luteum may show high signal | no enhancement corpus luteum may enhance | reproductive age |
Serous cystadenoma | often bilateral, thin regular wall (<3 mm) no internal septations, papillary projections or solid components | high | low | no enhancement | ||
Cystadenofibroma | sometimes: purely cystic lesion more often: complex cystic appearance with thick septa and solid components | high fibrous stroma: low signal intensity | low | no enhancement | ||
Cystic multilocular | Endometriosis | haemorrhagic content | intermediate to low shading sign | high | no enhancement | reproductive age |
Mucinous cystadenoma | thin regular wall, several septations, no solid components monolateral | variable signal intensity (stained glass appearance) | no enhancement | |||
Borderline tumours | septa, papillary projections | intermediate | intermediate | enhancement of septa and papillary projections | 45 younger patients than malignant ovarian cancer | |
Cystic and solid | Mature cystic teratoma | complex, heterogeneous appearance fat-tissue content | fat-tissue: high fat-tissue: low on fat-saturated sequences teeth: low signal intensity | variable | 35 | |
Struma ovarii (monodermal teratoma) | complex mass with cystic spaces of variable signal intensity and solid areas thyroid tissue: thyrotoxicosis | cystic spaces with both high and low signal intensity cystic spaces with low signal intensity because of the colloid of the struma | enhancement of the cystic wall and solid components | 50 | ||
Ovarian metastasis | more often bilateral with a cystic and solid or a predominant solid morphological appearance from stomach, colon, breast, lung, contralateral ovary | intermediate to high | low to intermediate | enhancement of the cystic wall and solid components | ||
Serous cystadenocarcinoma | complex multilocular masses, thick and irregular walls, septations, solid components and papillary projections frequently bilateral | cystic: high solid: low | cystic: low to intermediate solid: intermediate | enhancement of walls, septations, solid components and papillary projections | 60 | |
Mucinous cystadenocarcinoma | complex multilocular masses, thick and irregular walls, septations, solid components and papillary projections | cystic: high solid: low mucinous: variable | cystic: low to intermediate solid: intermediate mucinous: variable | enhancement of walls, septations, solid components and papillary projections | ||
Endometrioid adenocarcinoma | complex masses with solid and cystic components associated with endometriosis | haemorrhagic areas: intermediate | haemorrhagic areas: high | enhancement of walls and solid components | 50–60 | |
Yolk sac tumour | mixed cystic and solid mass | haemorrhagic areas: intermediate | haemorrhagic areas: high | bright dot sign: foci of enhancement, dilated vessels | 15–25 | |
Granulosa cell tumours | mixed cystic and solid mass hyperestrogenism, endometrial hyperplasia | cystic: high haemorrhagic: high solid: intermediate | cystic: low haemorrhagic: high solid: intermediate | enhancement of walls and solid components | 60 | |
Predominantly solid | Brenner tumour | fibrous content, calcifications | low | low to intermediate | no enhancement | 50–70 |
Dysgerminoma | lobulated lesion with fibrovascular septa, surrounded by a fibrotic capsule | solid component: intermediate to high septa: low | low to intermediate | enhancement of solid components and septa | 25 | |
Fibrothecomas | fibrous tissue theca cells with lipidic content | low to intermediate | low to intermediate | minimal enhancement | 60 | |
Fibromas | prominent fibrosis with abundant collagen content | low | low | moderate enhancement | 60 | |
Thecomas | mainly lipidic content of theca cells | intermediate | intermediate lipidic content: low at chemical-shift (out of phase) | minimal enhancement | 60 | |
Sertoli-Leydig cell tumours | solid mass or mixed cystic and solid mass 1/3 patients: signs of androgen activity | solid component: low scattered cystic areas: high | solid component: intermediate | enhancement of solid components | 25–30 |
Unilocular cystic masses
Multilocular cystic masses
Cystic and solid masses
Predominantly solid masses
Conclusion
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non-neoplastic lesions should always be taken into consideration;
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in a patient with endometriosis, the presence of a complex and rapidly growing mass with contrast enhancement should raise the suspicion of endometrioid or clear cell tumour;
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a very low signal intensity on T2-weighted images indicates a fibrotic component, suggesting a tumour of the thecoma/fibroma group, a cystadenofibroma or a Brenner tumour;
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sequences with fat saturation are helpful when facing a mass with high signal intensity on T1-weighted images, because the signal suppression is suggestive of a teratoma; otherwise, an endometrial cysts or other haemorrhagic lesions should be considered;
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a “stained glass appearance” with cystic loculi of variable signal intensity usually refers to a mucinous tumour, because of the different mucin concentration;
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metastasis should be considered if a complex enhancing mass is demonstrated in both ovaries (eventually looking for an unknown primary tumour); however, it must be remembered that serous epithelial tumours can be bilateral as well.