Differentiating cellular leiomyoma from uterine sarcoma and atypical leiomyoma using multi-parametric MRI

Clinical Features and Imaging Findings of Low-Grade Endometrial Stromal Sarcoma: A Retrospective Case Series-Based Analysis

OBJECTIVE

This case series presents six cases of low-grade endometrial stromal sarcoma (LGESS) and discusses their magnetic resonance imaging (MRI) findings in light of recent advancements in LGESS diagnosis.

METHODS

Data from six cases of LGESS treated at Fukui University Hospital between June 2007 and October 2024 were retrospectively analyzed. The clinical behavior, histopathological features, therapeutic approaches, and survival outcomes were evaluated. MRI images were assessed by two radiologists over multiple parameters that were considered specific to the LGESS.

RESULTS

Among the six patients with LGESS, four patients had tumors located within the myometrium, whereas two patients had tumors located in the submucosal layer. All cases were classified as International Federation of Gynecology and Obstetrics Stage Ⅰ, and no recurrence was observed during follow-up. On MRI, all six tumors exhibited high signal intensity on T2-weighted images (T2WI), compared to the myometrium, and high signal intensity on diffusion-weighted images (DWI), compared to the endometrium. In four of the five evaluable cases, the mean apparent diffusion coefficient (ADC) value was 0.86 × 10⁻³ mm²/s (range: 0.81-0.99).

CONCLUSION

Both clinically and based on imaging findings, distinguishing between LGESS and rare leiomyoma variants is challenging. MRI findings, including high signal intensity on T2WI and DWI as well as low ADC values, may prove valuable in differentiating these two entities.

The utility of MRI for the preoperative differential diagnosis of uterine sarcoma and leiomyoma: a single-center study

Although uterine sarcoma is a rare disease, its prognosis is extremely poor;thus, it is important to differentiate it from uterine leiomyoma.　In this retrospective study, we examined the association between preoperative MRI findings and postoperative pathology results in 170 patients with uterine tumors who underwent preoperative MRI examination at Fukushima Red Cross Hospital.　In 4 cases of sarcoma / smooth muscle tumor of unknown malignant potential (STUMP), abnormal findings were found at a high frequency with T1-weighted imaging (T1WI) (75%), T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and contrast enhancement (CE) (100%).　In cases of ordinary leiomyoma, on the other hand, abnormal findings were less frequent.　The rates of high DWI signal intensity for degenerated and cellular leiomyoma were 31% and 64%, respectively, and the CE-positive rates were 31% and 57%, respectively.　Apparent Diffusion Coefficient (ADC) values appeared to be useful in differentiating degenerated leiomyoma from sarcoma.　The relatively characteristic findings of uterine sarcoma on MRI images may overlap with those of degenerated leiomyoma and cellular leiomyoma, making it difficult to diagnose sarcoma on imaging alone.　However, findings that distinguish sarcoma from ordinary, degenerated, and cellular leiomyoma cases are worthy of attention, to avoid overlooking sarcoma.

Utility of ADC Values for Differentiating Uterine Sarcomas From Leiomyomas: Systematic Review and Meta-Analysis

BACKGROUND. Uterine sarcomas are rare; however, they display imaging features that overlap those of leiomyomas. The potential for undetected uterine sarcomas is clinically relevant because minimally invasive treatment of leiomyomas may lead to cancer dissemination. ADC values have shown potential for differentiating benign from malignant uterine masses. OBJECTIVE. The purpose of this study was to perform a systematic review of the diagnostic performance of ADC values in differentiating uterine sarcomas from leiomyomas. EVIDENCE ACQUISITION. We searched three electronic databases (the MEDLINE, Embase, and Cochrane databases) for studies distinguishing uterine sarcomas from leiomyomas using MRI, including ADC values, with pathologic tissue confirmation or imaging follow-up used as the reference standard. Data extraction and QUADAS-2 quality assessment were performed. Sensitivity and specificity were pooled using hierarchical models, including bivariate and hierarchical summary ROC models. Metaregression was used to assess the impact of various factors on heterogeneity. EVIDENCE SYNTHESIS. Twenty-one studies met the study inclusion criteria. Pooled sensitivity and specificity were 89% (95% CI, 82-94%) and 86% (95% CI, 78-92%), respectively. The area under the summary ROC curve was 0.94 (95% CI, 0.92-0.96). The context of the ADC interpretation (i.e., used as a stand-alone assessment vs integrated as part of multiparametric MRI [mpMRI]) was the only factor found to account significantly for heterogeneity (p = .01). Higher specificity (95% [95% CI, 92-99%] vs 82% [95% CI, 75-89%]) and similar sensitivity (94% [95% CI, 89-99%] vs 88% [95% CI, 82-93%]) were observed when ADC was evaluated among mpMRI features rather than as a stand-alone ADC assessment. ADC cutoff values ranged from 0.87 to 1.29 × 10-3 mm2/s but were not associated with statistically different performance (p = .37). Pooled mean ADC values for sarcomas and leiomyomas were 0.904 × 10-3 mm2/s and 1.287 × 10-3 mm2/s, respectively. CONCLUSION. As part of mpMRI evaluation of uterine masses, a mass ADC value of less than 0.904 × 10-3 mm2/s may be a useful test-positive threshold for uterine sarcoma, consistent with the findings of a prior expert consensus statement. Institutional protocols may influence locally selected ADC values. CLINICAL IMPACT. Using ADC as part of mpMRI assessment improves detection of uterine sarcoma, which could influence candidate selection for minimally invasive treatments. TRIAL REGISTRATION. Prospective Register of Systematic Reviews CRD42024499383.

Abnormal Uterine Bleeding: A Pictorial Review on Differential Diagnosis and Not-So-Common Cases of Interventional Radiology Management

Abnormal uterine bleeding (AUB) poses a multifaceted challenge in women's health, necessitating an integrated approach that addresses its diverse etiologies and clinical presentations. The International Federation of Gynecology and Obstetrics PALM-COEIN classification system provides a systematic approach to the diagnosis of AUB in non-pregnant women, based on clinical and imaging-based categorization of causes into structural (Polyps, Adenomyosis, Leiomyomas and Malignancy; PALM), and non-structural causes (Coagulopathies, Ovulatory disorders, primary Endometrial disorders, Iatrogenic and Not otherwise classified; COEIN). On the other hand, placental disorders, uterine rupture, ectopic pregnancy and retained products of conceptions are the main causes of uterine bleeding during pregnancy and in the peripartum period. Ultrasound is usually the first-line imaging technique for the differential diagnosis of causes of AUB. Computed Tomography may be useful if ultrasound findings are unclear, especially in emergency settings. Magnetic resonance imaging, when indicated, is an excellent second-line diagnostic tool for a better non-invasive characterization of the underlying cause of AUB. This pictorial review aims to illustrate the main causes of AUB from the point of view of diagnostic imaging and to show not-so-common cases that can be treated by means of interventional radiology.

Recurrence complicated with peritoneal dissemination after single-port gasless myomectomy for cellular uterine leiomyoma: A case report and literature review

RATIONALE

Cellular uterine leiomyomas (CL) represent the prevailing subtype among uterine leiomyomas. In this study, we report a case of recurrent peritoneal disseminated uterine fibroids 2 years after single-port laparoscopic gasless myomectomy. This article endeavors to examine the potential limitations of the aforementioned surgical procedure and outline the distinguishing features of recurrent cases with primary postoperative pathology as CL. Additionally, it aims to provide a summary of previous retrospective studies on CL and propose the existence of immunohistochemical molecules that may serve as predictors for the postoperative recurrence of cellular uterine fibroids. The ultimate objective is to enhance clinicians' comprehension of the disease.

PATIENT CONCERNS

Two years ago, the patient underwent a single-port gasless laparoscopic myomectomy for uterine fibroids. Gynecological color Doppler ultrasound conducted 3 months ago revealed recurrence of uterine fibroids, and the patient experienced abdominal distension, mild urinary frequency, and constipation for the past month.

DIAGNOSES

After the second surgical procedure, a comprehensive pathological examination and immunohistochemical analysis of both the uterine mass and metastatic lesions revealed that the definitive diagnosis was CLs.

INTERVENTIONS

The patient underwent the total hysterectomy, bilateral salpingectomy, pelvic adhesiolysis, omental mass resection, mesenteric mass resection, and pelvic peritoneal mass resection. All specimens were sent for rapid frozen examination and showed to be leiomyomas.

OUTCOMES

The patient was discharged from the hospital on the 10th day after the operation. At the date of writing the article, the patient had no recurrence for 1 year and 5 months.

LESSONS

The single-port gasless approach did not achieve the desired reduction in fibroid recurrence, as anticipated by the surgeon. The act of pulling the tumor towards the abdominal incision for resection, on the contrary, may serve as an iatrogenic factor contributing to postoperative recurrence of CL into peritoneal dissemination leiomyomatosis. The single-port gasless assisted bag may be a more suitable option for myomectomy. The utmost effort should be made to prevent the potential recurrence of myoma caused by iatrogenic factors.

Leiomyoma or sarcoma? MRI performance in the differential diagnosis of sonographically suspicious uterine masses

PURPOSE

To assess the diagnostic performance of MRI in distinguishing between leiomyomas and malignant/potentially malignant mesenchymal neoplasms in patients with rapidly enlarging/sonographically suspicious uterine masses.

METHODS

IRB-approved retrospective study including 88 patients (51 ± 11 years) who underwent MRI for rapidly enlarging/sonographically suspicious uterine mass at our Institution between January 2016 and December 2021, followed by surgery or >12 months follow-up. Qualitative image analysis was independently performed by 2 radiologists and included lesion's margins (sharp/irregular), architecture (homogeneous/inhomogeneous), presence of endometrial infiltration (yes/no), necrotic areas (yes/no), hemorrhagic areas (yes/no), predominant signal intensity on T1-WI, T2-WI, CE T1-WI, DWI, and ADC map. The same radiologists performed quantitative image analysis in consensus, which included lesion's maximum diameter, lesion/myometrium signal intensity ratio on T2-WI and CE T1-weighted images, lesion/endometrium signal intensity ratio on DWI and ADC map and necrosis percentage. Lesions were classified as benign or malignant. Imaging findings were compared with pathology and/or follow-up.

RESULTS

After surgery (52/88 patients) or follow-up (36/88 patients, 33 ± 20 months), 83/88 (94.3%) lesions were classified as benign and 5/88 (5.7%) as malignant/potentially malignant. Presence of necrotic areas, high necrosis percentage, hyperintensity on DWI and high lesion/endometrium DWI signal intensity ratio were significantly associated with malignant/potentially malignant lesions (p = 0.027, 0.002, 0.008 and 0.015, respectively). The two readers identified malignant/potentially malignant lesions with 95.5% accuracy, 80.0% sensitivity, 96.4% specificity, 57.1 % PPV, 93.3% NPV.

CONCLUSION

MRI has high accuracy in identifying malignant/potentially malignant myometrial masses. In everyday practice, however, MRI positive predictive value is relatively low given the low pre-test malignancy probability.