We present the appearance of MR imaging of 20 patients with CCCs performed MRI with 1.5T unit and confirmed pathologically by surgery in our hospital from 2013 to 2017.
DWI was obtained on b=0,
b=800 before June 2016 and was obtained on b=0,1000 after June 2016.
In addition to the pathological diagnosis,
we evaluated six factors of CCCs in order to compare with the previous studies as follows;
a) age
b) FIGO stage
c) CA125 value
d) maximum tumor size
e) protrusions within the tumor
e-1 shape; papillary or broad-based
e-2 internal SI on T2WI; high,
intermediate,
low
e-3 enhanced pattern during dynamic MRI; mild,
moderate,
prominent
e-4 signal intensity (SI) on DWI; high,
moderate,
low
e-5 measurement of the mean ADC values within the protrusions.
We defined the ROI with abnormal signal intensity on T2WI,
higher signal intensity on DWI and lower signal intensity on ADC map and carefully eliminated hemorrhagic lesion on T1WI,
necrosis on dynamic contrast MRI and “T2 blackout effect”.
f) pathological features; necrosis,
hemorrhage,
inflammation,
edema,
predominance of solid or papillary pattern and existence of fibrous stroma.
Classification of the morphology and signal intensity of solid component in CCCs on T2WI
Based on the shape of solid protrusions,
signal intensity on T2WI and enhancement pattern,
we classified MR imaging into two major types of type1) :papillary protrusions of intermediate signal intensity on T2WI,
type 2) :broad-based protrusions of intermediate signal intensity on T2WI,
and other combination such as a) prominent enhanced protrusion,
b) various shapes of solid components with various signal intensity on T2WI,
c) smooth surfaced solid component with intermediate signal intensity on T2WI and d) papillary protrusions of high signal intensity on T2WI (Fig.7).
MRI types,
age,
FIGO stage,
CA125 value,
maximum tumor size and the mean ADC values were summarized in Table (Table 1).
In our results,
MRI classification accounted for
MRI type was resulted in Type 1: 11 of 20 cases (55%),
Type 2: 5 of 20 cases (25%) and other type: 4 of 20 cases (5% respectively).
age
Age 20 patients was ranged from 37 to 80 years at the median age of 53.65 years that was coincident with the previous report [2].
FIGO stage
FIGO stage was recognized from IA (7/20),
IC1(5/20) IC2(1/20),
IC3(1/20),
IIA (2/20),
IIIC (2/20),
and IVA (2/20) respectively.
This result was not coincident with the previous report mentioned that stage IC was the most frequent at about 35-60% of incidence [3].
CA125 level
CA125 was ranged from 28.9 to 3557.9U/ml at the median level of 90.2U/ml that was not speculated significant due to wide range.
size
The tumor maximum size was measured from 7.5 to 32cm at the median size of 13.0cm that was almost coincident with the previous report [3].
Concerning of the growth pattern of solid protrusions,
predominantly eccentric pattern was recognized in only 50% that was less than the previous study [9].
It was difficult to differentiate the growth pattern,
when the solid components occupied more than half of the tumor,
widely occupied along the lumen of tumors and distributed at the multiple sites within the tumor.
mean ADC values
In each case,
mean ADC value was measured for the ROI focusing the lower SI on ADC map with the highest SI on DWI and enhanced lesion on dynamic contrast MRI to eliminate tumor necrosis.
ADC values were obtained1.26 ± 0.22 x10-3mm2/s on DWI b=0,
800 images and 1.15 ± 0.18x10-3mm2/s obtained on DWI b=0,1000 images (Fig.9)..
On T1WI,
hemorrhagic cysts seen on MRI: seventeen of 20 cases
Endometriosis was identified pathologically in twelve of 20 patients.
Re-evaluating both of MR imaging and pathological features,
we estimated some possibilities in each case.
Type 1: papillary protrusions of intermediate SI on T2WI (Fig.10)
The reason why papillary protrusions show heterogeneous signal intensity on T2WI and moderate enhancement is possible to reflect hemorrhagic and necrotic changes that is proven pathologically.
Type 2: broad-based protrusions of intermediate SI on T2WI (Fig.11)
High signal intensity on DWI and mild enhancement is suggestive of pathological features.
Microscopic findings show distribution of stroma is different between solid pattern with less stroma and papillary pattern with dense stroma that is expected an association with restricted water diffusion.
Others types:
1) prominent enhanced protrusions (Fig.12)
Papillary protrusions demonstrate moderately high signal intensity on T2WI and reveals prominent and prolonged enhancement on dynamic subtraction image.
This MRI finding is possible to be correlated with inflammatory changes that is confirmed pathologically.
2) various shapes of solid components with various SI on T2WI (Fig.13)
This tumor presents the most complicated SI and various enhancement on MRI because it consists of two components of serous adenofibroma and CCC.
Compared with macroscopic findings,
CCC is considered to occupy about 40% of this tumor and to coexist with adenofibroma sized in about 6cm.
3) smooth surfaced solid component with intermediate SI on T2WI (Fig.14)
Microscopic findings show dense fibrotic stroma is dominant in the part of CCC accompanied with huge serous cystadenofibroma.
It is difficult to differentiate malignant from benign tumor from MRI findings because when moderate high SI on DWI with low SI on ADC map is demonstrated as a result of “T2 blackout effect”
4) papillary protrusions of high SI on T2WI (Fig.15)
Microscopic findings show papillary pattern is dominant with hemorrhage and necrosis in the surface of tumor.
Edematous change is also seen in the fibrotic stroma and excretion is seen in the papillary pattern that is suggestive of inflammatory change.
That is why protrusion shows high SI on T2WI.