MRI for differentiating ovarian endometrioid adenocarcinoma from high-grade serous adenocarcinoma

Abstract

Purpose: To investigate magnetic resonance imaging (MRI) features for differentiating ovarian endometrioid adenocarcinoma (OEC) from high-grade serous adenocarcinoma (HGSC).

Materials and methods: Twenty-three patients with 25 OECs and 93 patients with 139 HGSCs confirmed by surgery and pathology underwent conventional MRI and diffusion-weighted imaging (DWI). The MRI features of the tumors, including laterality, size, shape, configuration, signal intensity, ADC value of solid component, enhancement, ascites, synchronous primary cancer (SPC) of the ovary and endometrium, and clinical stage, were evaluated and compared between two groups.

Results: The following characteristics were significantly more common for OECs than HGSCs: unilateral (91.3% vs 50.5%, P < 0.001), larger mass (80.0% vs 48.2%, P = 0.005), round or oval shape (64.0% vs 17.3%, P < 0.001), mainly cystic with mural nodules or papillary projections (72.0% vs 18.7%, P < 0.001), cystic component with homogeneous iso- or hyperintensity on T1WI (82.6% vs 4.3%, P < 0.001), moderate enhancement (52.0% vs 26.6%, P = 0.011), no or mild ascites (91.3% vs 57.0%, P = 0.002), and SPC (43.5% vs 4.3%, P < 0.001). The ADC value of the solid component was higher in OECs (0.979 ± 0.197 × 10(-3) mm(2)/s) than in HGSCs (0.820 ± 0.112 × 10(-3) mm(2)/s) (P = 0.002). When a mainly cystic mass with mural nodules or papillary projections was associated with any one of homogeneously iso- or hyperintense cystic component on TIWI, a relatively higher ADC value and SPC, the sensitivity, specificity, accuracy, and positive and negative predictive values for characterizing OEC were 87.0%, 93.5%, 92.2%, 76.9%, and 96.7%, respectively.

Conclusions: Conventional MRI combining DWI is helpful for differentiating OECs from HGSCs.

Figure 1

A 50-year-old woman with right-sided OEC. The tumor appears as a mainly cystic mass with a large mural nodule. The cystic component (crossstar) shows slight hyperintensity on axial T1WI (a), homogeneous hyperintensity on axial T2WI with fat suppression (b), no enhancement on contrast-enhanced T1WI with fat suppression (c), isointensity on DWI (d). The mural nodule (arrow) demonstrates isointensity (a), heterogenous hyperintensity (b), marked enhancement (c) and hyperintensity (d) with an ADC value of 1.030 × 10⁻³ mm²/s, respectively. Synchronous uterine endometrial carcinoma (arrowhead) shows mild enhancement on contrast-enhanced T1WI and hyperintensity on DWI.

Figure 2

A 32-year-old woman with left-sided OEC. Axial and sagittal T2WI (a, c) demonstrate a mainly cystic mass with multiple mural nodules (arrows). Axial and sagittal contrast-enhanced T1WI with fat suppression (b, d) show that the nodules are moderately enhanced.

Figure 3

A 53-year-old woman with left-sided OEC. Contrast-enhanced T1WI with fat suppression (a) demonstrates a mainly cystic mass with mural nodules (arrow), which show a marked enhancement (a) and a hyperintensity on DWI (b) with an ADC value of 1.174 × 10⁻³ mm²/s(c).

Figure 4

A 67-year-old woman with left-sided HGSC. Axial T2WI (a) demonstrates a solid mass (short arrow) with an irregular shape and a large volume of ascites (long arrow). The mass is markedly enhanced with irregular areas of necrosis (asterisk) on contrast-enhanced T1WI with fat suppression (b), hyperintensity on DWI (c) and hypointensity on ADC map with an ADC value of 0.682 × 10⁻³ mm²/s (d).

Figure 5

A 57-year-old woman with bilateral HGSC. Axial T2WI (a) demonstrates a solid mass (long arrow) in the right-sided ovary and a mixed cystic-solid mass (short arrow) in the left-sided ovary, which have an irregular shape. A large volume of ascites is observed. The solid components of the masses and peritoneal nodules (arrows) are enhanced markedly on contrast-enhanced T1WI with fat suppression (b), hyperintensity on DWI (c) and hypointensity on ADC map (d) with an ADC value of 0.759 × 10⁻³ mm²/s (left) and 0.782 × 10⁻³ mm²/s (right).