Risk assessment and prediction of occult uterine sarcoma in patients with presumed uterine fibroids before high-intensity focused ultrasound treatment

Figures & data

Figure 1. Flowchart of patient enrollment.

Table 1. Comparison of baseline characteristics between patients with uterine fibroids and occult uterine sarcoma.

Variables	Patients with uterine fibroids (N = 54)	Patients with occult uterine sarcoma (N = 27)	z/t/χ2	P
Age (year)	43.5 (33.0–48.0)	44.0 (41.0–49.0)	−0.778	0.437
BMI(kg/m^2)	22.2 ± 2.3	23.2 ± 2.9	−1.583	0.117
Rate of menopause	3 (5.6%)	2 (7.4%)	0.000	1.000
Rate of unpregnant patients	16 (29.6%)	3 (11.1%)	3.438	0.064
Lesion volume (cm^3)	79.4 (42.7–148.0)	109.0 (47.1–240.7)	−1.212	0.225

Table 2. Comparison of clinical features between patients with uterine fibroids and patients with occult uterine sarcoma.

Variables	Patients with uterine fibroids (N = 54)	Patients with occult uterine sarcoma (N = 27)	χ2	P
6-month course of the disease	24 (44.4%)	13 (48.1%)	0.100	0.752
Rapid growth	2 (3.7%)	4 (14.8%)	1.822	0.177
Large menstruation	12 (22.2%)	15 (55.6%)	9.000	0.003
Abnormal vaginal bleeding	7 (13.0%)	15 (55.6%)	16.506	<0.001
Abdominal pain and distension	4 (7.4%)	8 (29.6%)	5.393	0.020
Pelvic lumps	2 (3.7%)	4 (14.8%)	1.822	0.177
Pressure symptom	4 (7.4%)	3 (11.1%)	0.020	0.889

Table 3. Comparison of lab test results between patients with uterine fibroids and patients with occult uterine sarcoma.

Variables	Patients with uterine fibroid (N = 54)	Patients with occult uterine sarcoma (N = 27)	Z	P
NLR	1.9 (1.5–2.7)	2.7 (2.0–3.7)	−2.790	0.005
PLR	132.5 (106.2–193.7)	169.1 (119.5–283.1)	−2.405	0.016
LMR	4.7 (3.7–6.5)	4.3 (3.1–5.8)	−1.292	0.196
Hemoglobin (g/L)	122.0 (110.5–129.0)	107.0 (95.0–124.0)	−2.431	0.015
Anemia	16 (29.6%)	17 (63.0%)	8.284	0.004

NLR: ratio of neutrophil to lymphocyte; PLR: ratio of platelet to lymphocyte; LMR: ratio of lymphocyte to monocyte.

Table 4. Comparison of MRI findings in patients with uterine fibroids and patients with occult uterine sarcoma.

Variables	Patients with uterine fibroids (N = 54)	Patients with occult uterine sarcoma (N = 27)	χ2	P
Solitary mass	31 (57.4%)	21 (77.8%)	3.250	0.071
Mass position			5.870	0.118
Anterior wall	16 (29.6%)	10 (37.0%)
Posterior wall	10 (18.5%)	10 (37.0%)
Lateral wall	21 (38.9%)	6 (22.2%)
Fundus	7 (13.0%)	1 (3.7%%)
Type of Mass			12.474	0.002
Subserosal	24 (44.4%)	2 (7.4%)^a
Intermural	25 (46.3%)	18 (66.7%)
Submucosal	5 (9.3%)	7 (25.9%)
Irregular shape	11 (20.4%)	9 (33.3%)	1.627	0.202
Unclear boundary	13 (24.1%)	21 (77.8%)	21.314	<0.001
T2 signal intensity of Mass			22.718	<0.001
Hyperintense	9 (16.7%)	18 (66.7%)^b^cd
Isointense	8 (14.8%)	1 (3.7%)
Hypointense	18 (33.3%)	1 (3.7%)
Heterogeneous signal intensity	19 (35.2%)	7 (25.9%)
Inside the mass separate or cystic cavity	10 (18.5%)	16 (59.3%)	13.708	<0.001
T1 signal intensity of Mass			12.169	0.004
Hyperintense	4 (7.4%)	6 (22.2%)
Isointense	43 (79.6%)	11 (40.7%)
Hypointense	2 (3.7%)	3 (11.1%)
Heterogeneous signal intensity	5 (9.3%)	7 (25.9%)
Contrast enhancement			24.232	<0.001
Significant enhancement	10 (18.5%)	2 (7.4%)
Moderate enhancement	14 (25.9%)	4 (14.8%)
Weak enhancement	14 (25.9%)	4 (14.8%)
No enhancement in the surrounding area	11 (20.4%)	1 (3.7%)
No enhancement in the central area	5 (9.3%)	16 (59.3%) ^e^fgh
Restricted diffusion	17 (31.5%)	18 (66.7%)	9.081	0.003

^aIndicated a significant difference in incidence between the type of subserosal and the type of submucosal, p < 0.017.

^bIndicated a significant difference in incidence between hyperintense and isointense lesions, p < 0.008.

^cIndicated a significant difference in incidence between hyperintense and hypointense lesions, p < 0.008.

^dIndicated a significant difference in incidence between lesions with hyper-intensity and lesions with heterogeneous signal intensity, p < 0.008.

^eIndicated a significant difference in incidence between lesions with no enhancement in the central area and lesions with significant enhancement, p < 0.005.

^fIndicated a significant difference in incidence between lesions with no enhancement in the central area and lesions with moderate enhancement, p < 0.005.

^gIndicated a significant difference in incidence between lesions with no enhancement in the central area and lesions with weak enhancement, p < 0.005.

^hIndicated a significant difference in incidence between lesions with no enhancement in the central area and lesions with no enhancement in the surrounding area, p < 0.005.

Table 5. Results of the logistics regression analysis for patients with occult uterine sarcoma.

Characteristic	B	se	OR (95%CI)	P
Abnormal vaginal bleeding	3.117	1.228	22.571 (2.033,250.555)	0.011
Unclear boundary	5.003	1.604	148.835 (6.422, 3449.561)	0.002
Hypointensity on T2				0.028
Isointensity /Heterogeneous signal on T2	2.264	1.978	9.622 (0.199, 464.473)	0.252
Hyperintensity on T2	5.203	2.333	181.764 (1.878, 17587.736)	0.026
No enhancement in the surrounding area				0.014
Uniform enhancement of lesions (including significant, moderate and poor enhancement)	1.093	1.416	2.983 (0.186, 47.818)	0.440
No enhancement in the central area	5.569	2.047	262.063 (4.740, 14489.734)	0.007
Constant	−10.58	3.544		0.003

Figure 2. Nomogram for independent risk factors in predicting uterine sarcoma. The corresponding score of each independent risk factor was visualized on the nomogram. The total score was obtained by adding up the scores of independent risk factor.

Figure 3. ROC Curve of the nomogram model. The AUC was 0.969 (95% confidence interval: 0.937–0.991, p < 0.001).

Figure 4. Calibration curve of the predictive model. The predicted value of occult uterine sarcoma obtained by the nomogram met well with the actual observed value.

Figure 5. MR images obtained from a 32-year-old patient who reported no abnormal vaginal bleeding. A. T2WI showed a hypointense tumor with clear boundary. B. Contrast-enhanced MRI showed mild enhancement of tumor. According to the nomogram chart, the scores for no abnormal vaginal bleeding clear margin of tumor, low signal intensity on T2WI, and weak enhancement were 0, 0, 0, and 20 points. The total score was 20 points. The final diagnosis was uterine fibroids after surgery.

Figure 6. MRI obtained from a 46-year-old patient who did not report abnormal vaginal bleeding. A. T2WI of MRI showed a hyperintense mass with an irregular margin. B. Contrast enhanced MRI showed no enhancement in the center of the lesion. According to the nomogram chart, the patient scored 0 points for no abnormal vaginal bleeding, 90 points for unclear margin of the lesion, 93 points for hyperintensity on T2WI, 100 points for no enhancement in the central area. The total score for this patient was 283 points. The diagnosis of uterine sarcoma was confirmed after surgery.

Data availability statement

The data that support the findings of this study are available upon request from the corresponding author, LZ. The data are not publicly available because they contain information that can compromise the privacy of the research participants.