Differentiation of Seromucinous Borderline Tumor from Serous Borderline Tumor on MR Imaging

Endometriosis, a common but enigmatic disease with many faces: current concept of pathophysiology, and diagnostic strategy

Endometriosis is a benign, common, but controversial disease due to its enigmatic etiopathogenesis and biological behavior. Recent studies suggest multiple genetic, and environmental factors may affect its onset and development. Genomic analysis revealed the presence of cancer-associated gene mutations, which may reflect the neoplastic aspect of endometriosis. The management has changed dramatically with the development of fertility-preserving, minimally invasive therapies. Diagnostic strategies based on these recent basic and clinical findings are reviewed. With a focus on the presentation of clinical cases, we discuss the imaging manifestations of endometriomas, deep endometriosis, less common site and rare site endometriosis, various complications, endometriosis-associated tumor-like lesions, and malignant transformation, with pathophysiologic conditions.

MR Relaxometry for Discriminating Malignant Ovarian Cystic Tumors: A Prospective Multicenter Cohort Study

BACKGROUND

Endometriosis-associated ovarian cancer (EAOC) is a well-known type of cancer that arises from ovarian endometrioma (OE). OE contains iron-rich fluid in its cysts due to repeated hemorrhages in the ovaries. However, distinguishing between benign and malignant tumors can be challenging. We conducted a retrospective study on magnetic resonance (MR) relaxometry of cyst fluid to distinguish EAOC from OE and reported that this method showed good accuracy. The purpose of this study is to evaluate the accuracy of a non-invasive method in re-evaluating pre-surgical diagnosis of malignancy by a prospective multicenter cohort study.

METHODS

After the standard diagnosis process, the R2 values were obtained using a 3T system. Data on the patients were then collected through the Case Report Form (CRF). Between December 2018 and March 2023, six hospitals enrolled 109 patients. Out of these, 81 patients met the criteria required for the study.

RESULTS

The R2 values calculated using MR relaxometry showed good discriminating ability with a cut-off of 15.74 (sensitivity 80.6%, specificity 75.0%, AUC = 0.750, p < 0.001) when considering atypical or borderline tumors as EAOC. When atypical and borderline cases were grouped as OE, EAOC could be distinguished with a cut-off of 16.87 (sensitivity 87.0%, specificity 61.1%).

CONCLUSIONS

MR relaxometry has proven to be an effective tool for discriminating EAOC from OE. Regular use of this method is expected to provide significant insights for clinical practice.

A case of paraovarian tumor of borderline malignancy with decrease of apparent diffusion coefficient value and marked 18F-fluorodeoxyglucose accumulation

Para-ovarian cysts are occasionally encountered in clinical practice; however, malignant tumors derived from them are rare. Due to its rarity, the characteristic imaging findings of para-ovarian tumors with borderline malignancy (PTBM) are largely unknown. Herein, we report a case of PTBM, along with imaging findings. A 37-year-old woman came to our department with a suspected malignant adnexal tumor. Pelvic contrast-enhanced magnetic resonance imaging (MRI) revealed a solid part within the cystic tumor with a decrease in the apparent diffusion coefficient (ADC) value (1.16 × 10-3 mm2/s). We also performed Positron Emission Tomography-MRI and showed a strong accumulation of 18F-fluorodeoxyglucose (FDG) in the solid part (SUVmax = 14.8). In addition, the tumor appeared to develop independently of the ovary. Because tumor was derived from para-ovarian cyst, we suspected PTBM preoperatively and planned fertility sparing treatment. Pathological examination revealed a serous borderline tumor and PTBM was confirmed. PTBM can have unique imaging characteristics, including a low ADC value and high FDG accumulation. When a tumor appears to develop from para-ovarian cysts, borderline malignancy can be suspected, even if imaging findings suggest malignant potential.

Whole-tumor ADC histogram analysis for differentiating endometriosis-related tumors: seromucinous borderline tumor, clear cell carcinoma and endometrioid carcinoma

PURPOSE

To investigate the feasibility of whole-tumor apparent diffusion coefficient (ADC) histogram analysis for improving the differentiation of endometriosis-related tumors: seromucinous borderline tumor (SMBT), clear cell carcinoma (CCC) and endometrioid carcinoma (EC).

METHODS

Clinical features, solid component ADC (ADC_SC) and whole-tumor ADC histogram-derived parameters (volume, the ADC_mean, 10th, 50th and 90th percentile ADCs, inhomogeneity, skewness, kurtosis and entropy) were compared among 22 SMBTs, 42 CCCs and 21 ECs. Statistical analyses were performed using chi-square test, one-way ANOVA or Kruskal-Wallis test, and receiver operating characteristic curves.

RESULTS

A significantly higher ADC_SC and smaller volume were associated with SMBT than with CCC/EC. The ADC_mean was significantly higher in CCC than in EC. The 10th percentile ADC was significantly lower in EC than in SMBT/CCC. The 50th and 90th percentile ADCs were significantly higher in CCC than in SMBT/EC. For differentiating SMBT from CCC, AUCs of the ADC_SC, volume, and 50th and 90th percentile ADCs were 0.97, 0.86, 0.72 and 0.81, respectively. For differentiating SMBT from EC, AUCs of the ADC_SC, volume and 10th percentile ADC were 0.97, 0.71 and 0.72, respectively. For differentiating CCC from EC, AUCs of the ADC_mean and 10th, 50th and 90th percentile ADCs were 0.79, 0.72, 0.81 and 0.85, respectively.

CONCLUSION

Whole-tumor ADC histogram analysis was valuable for differentiating endometriosis-related tumors, and the 90th percentile ADC was optimal in differentiating CCC from EC.

MRI of Borderline Epithelial Ovarian Tumors: Pathologic Correlation and Diagnostic Challenges

Borderline epithelial ovarian tumors are a distinct pathologic entity characterized by increased epithelial proliferation and nuclear atypia, but without frank stromal invasion. Borderline tumor (BT) is now considered to represent an intermediate phase in the stepwise progression from benign to malignant ovarian epithelial tumor. Since BTs commonly manifest at early stages in women of reproductive age and are associated with a good prognosis, making the correct diagnosis is important in determining whether a patient is a candidate for fertility-sparing surgery. There are six histologic BT subtypes (serous, mucinous, seromucinous, endometrioid, clear cell, and Brenner), and each has different MRI features, reflecting their unique histologic architectures. Radiologists should be aware of the MRI features that can suggest BTs. These features include a hyperintense papillary architecture with hypointense internal branching, which can be observed with serous and seromucinous BTs on T2-weighted images; aggregates of microcysts that have hypointensity on T2-weighted images and reticular enhancement on contrast-enhanced T2-weighted images, which can be seen with mucinous BTs; and moderately high signal intensity on diffusion-weighted images along with relatively high apparent diffusion coefficient values, which can be observed regardless of the histologic subtype. Nevertheless, because the imaging features of BTs overlap with those of many benign lesions (eg, cystadenoma and cystadenofibroma, decidualized endometriosis, and polypoid endometriosis) and malignant tumors (ovarian cancers and metastases), histologic confirmation is required for the final diagnosis. Special emphasis is placed on the MRI features of BTs, pathologic correlation, and the challenges related to diagnosis. ^©RSNA, 2022.

Magnetic resonance imaging findings of cystic ovarian tumors: major differential diagnoses in five types frequently encountered in daily clinical practice

There are many types of ovarian tumors, and these different types often form cystic masses with a similar appearance, which can make their differentiation difficult. However, with the exclusion of rare ovarian tumors, the number of ovarian tumors encountered in daily practice is somewhat fixed. It goes without saying that magnetic resonance imaging (MRI) is useful for differentiating ovarian tumors. In this review, we summarize the differential diagnoses for each of the five types of MRI findings commonly encountered in daily practice. First, unilocular cystic masses without mural nodules/solid components include benign lesions such as serous cystadenoma, functional cysts, surface epithelial inclusion cysts, paratubal cysts, and endometriosis. Second, multilocular cystic ovarian lesions include mucinous tumors and ovarian metastases. It should be noted that mucinous tumors may be diagnosed as borderline or carcinoma, even if no solid component is observed. Third, cystic lesions with mural nodules that are unrelated to endometriosis include serous borderline tumor and serous carcinoma. Cystic lesions with solid components are more likely to be malignant, but some may be diagnosed as benign. Fourth, ovarian tumors deriving from endometriosis include seromucinous borderline tumors, endometrioid carcinoma, and clear cell carcinoma. These tumors sometimes need to be differentiated from serous tumors. Finally, cystic lesions with lipid contents include teratoma-related tumors. In mature cystic teratoma, mural nodules (called "Rokitansky protuberance" or "dermoid nipple") are sometimes seen, but they do not suggest malignancy. Some of these lesions can be diagnosed accurately by considering their characteristic imaging findings, their changes over time, MRI findings other than those of the primary lesion, and information from other modalities such as tumor markers. To ensure the optimal treatment for ovarian tumors, it is important to estimate the histological type as well as to diagnose whether a lesion is benign or malignant.

Clues to the diagnosis of borderline ovarian tumours: An imaging guide

Borderline Ovarian Tumours (BOTs) are an interesting subset of epithelial neoplasms defined histologically by atypical epithelial proliferation without stromal invasion. These tumours typically affect young women in the reproductive age group and have a good prognosis. Although ultrasonography is the primary screening imaging technique in the evaluation of any suspected adnexal mass, grey-scale and colour Doppler have limited value in characterizing BOTs. Thus, a pelvic magnetic resonance imaging (MRI) is recommended for further characterization on account of its multiplanar capabilities, excellent soft-tissue contrast and high spatial resolution. BOTs histological subtypes display specific features on MRI that are useful in differential diagnosis. However, the final diagnosis and staging of BOTs require pathologic evaluation after surgical excision. Therefore, the purpose of this review is to describe, illustrate and compare the imaging characteristics of the different subtypes of BOTs - serous, mucinous and seromucinous - focusing on MRI, as well as to correlate with pathology findings considering the recent 2020 World Health Organization (WHO) classification, in order to improve the accuracy of preoperative diagnosis and facilitate optimal patient management.

Serous borderline ovarian tumours: an extensive review on MR imaging features

Serous borderline ovarian tumours (SBOTs) are an intermediate group of neoplasms, which have features between benign and malignant ovarian tumours and for which, fertility-sparing surgery can be offered. MRI in imaging of SBOTs is, therefore, crucial in raising the possibility of the diagnosis, in order to present the patient with the most appropriate treatment options. There are characteristic MRI features that SBOTs demonstrate. In addition, recent advanced techniques, and further classification into subtypes within the borderline group have been developed. The aim of this article is to review the MRI features of SBOT and provide the reporter with an awareness of the imaging tips and tricks in the differential diagnosis of SBOT.

Ovarian seromucinous tumors: clinicopathological features of 10 cases with a detailed review of the literature

Background

The 2014 WHO Classification of ovarian neoplasms introduced a new entity of seromucinous tumors associated with endometriosis. These tumors encompassed a spectrum from benign to malignant and included seromucinous cystadenoma/ cystadenofibroma, seromucinous borderline tumor/atypical proliferative seromucinous tumor and seromucinous carcinoma. However, the 2020 WHO Classification of Female Genital Tumours removed seromucinous carcinomas as a distinct entity and recategorized them as Endometrioid carcinomas with mucinous differentiation. Here we describe clinico-morphologic features of seromucinous tumors recategorizing cases originally diagnosed as seromucinous carcinoma in light of 2020 WHO classification and present detailed review of literature.

Methods

Slides of seromucinous tumors were reviewed. Special emphasis was given to evaluation of stromal invasion. Follow-up was obtained.

Results

Ten cases were diagnosed. Mean age was 40 years. Four cases were bilateral. Mean size was 19 cm. Grossly; luminal papillary projections were seen in 6 cases. Tumors demonstrated a papillary architecture with papillae lined by stratified seromucinous epithelium showing nuclear atypia. Stromal invasion was seen in 4 cases. Six cases were reported as borderline seromucinous tumors and 4 cases originally diagnosed as seromucinous carcinoma were recategorized as endometrioid carcinoma with mucinous differentiation on review. Endometriosis was seen in 4 cases. CK7, PAX8 and ER were positive in 7/7 cases. Two cases showed extra-ovarian involvement. Follow up was available in 7 cases. Six patients were alive and well at follow up ranging from 8 to 46 months. Six patients received chemotherapy postoperatively. One patient with carcinoma died of disease 18 months postoperatively.

Conclusion

In our series, 4 cases were originally diagnosed as seromucinous carcinomas. However, these were recategorized in light of the 2020 WHO Classification of Female Genital tumors as endometrioid carcinomas with mucinous differentiation. Six cases were diagnosed as seromucinous borderline tumors. Thus, majority of cases were borderline in agreement with published literature.

Primary and recurrent serous borderline tumors during pregnancy: a case report and literature review

The diagnosis and management of borderline ovarian tumors during pregnancy are still not standardized, because these tumors are rarely encountered. We report the case of a 27-year-old pregnant woman who presented with an ovarian mass in her first trimester. Magnetic resonance imaging revealed a multilocular cystic component with papillary lesions in the background of endometriosis, suggesting a seromucinous borderline tumor or ovarian cancer. A right salpingo-oophorectomy and partial omentectomy were performed at 7 weeks of gestation. Pathological examination demonstrated a serous borderline tumor. The subsequent pregnancy course was uneventful, and she gave birth to a healthy baby at 39 weeks of gestation. She wanted to retain fertility, and close follow-up was performed. Four years later, she became pregnant, and a lesion suggesting recurrence in the left ovary was detected. An abdominal left ovarian cystectomy was performed at 13 weeks of gestation, which demonstrated recurrence of the serous borderline tumor. She gave birth to a healthy baby at 39 weeks of gestation. Two months after delivery, she underwent total abdominal hysterectomy with left salpingo-oophorectomy, which revealed no malignant findings. We also reviewed 10 reports that included 58 cases of borderline ovarian tumors diagnosed during pregnancy. The borderline ovarian tumors diagnosed during pregnancy exhibited different characteristics according to each subtype, suggesting the importance of diagnosing borderline ovarian tumor subtypes preoperatively.

MR findings for differentiating decidualized endometriomas from seromucinous borderline tumors of the ovary

PURPOSE

Decidualized endometriomas (DEs) and seromucinous borderline tumors (SMBTs) exhibit similar MR findings including markedly hyperintense mural nodules within endometriotic cysts on T2-weighted images. The present study aimed to assess the efficacy of MR imaging for differentiating between DEs and SMBTs of the ovary.

MATERIALS AND METHODS

MR images of 8 DEs and 14 SMBTs were retrospectively assessed and compared according to pathologies.

RESULTS

With regard to quantitative assessments of mural nodules, the number and signal intensity ratios (SIRs) on T1-weighted images were significantly greater in DEs than in SMBTs (11.0 ± 8.4 vs. 4.3 ± 4.1, p < 0.05 and 2.36 ± 0.56 vs. 1.49 ± 0.27, p < 0.01, respectively), whereas the height was significantly lower in DEs than in SMBTs (4.5 ± 1.4 mm vs. 21.9 ± 11.4 mm, p < 0.01). However, there were no significant differences between DEs and SMBTs in the SIRs on T2-weighted images, SIRs on diffusion-weighted images, and apparent diffusion coefficient values. With regard to qualitative assessments of mural nodules, the lobulated margin, pedunculated configuration, and T2 hypointense core were significantly more frequent in SMBTs than in DEs (71% vs. 0%, p < 0.01; 86% vs. 0%, p < 0.01; and 43% vs. 0%, p < 0.05, respectively).

CONCLUSION

The number, height, SIRs on T1-weighted images, lobulated margin, pedunculated configuration, and T2 hypointense core of mural nodules within endometriotic cysts were useful MR findings for differentiating DEs from SMBTs.

MR imaging findings of low-grade serous carcinoma of the ovary: comparison with serous borderline tumor

PURPOSE

To assess MR imaging findings of low-grade serous carcinoma (LGSC) of the ovary compared with those of serous borderline tumor (SBT).

METHODS

Twenty-four patients with histopathologically proven 7 LGSCs and 25 SBTs who underwent preoperative MR imaging were included. We retrospectively reviewed MR images and compared MR findings between the two pathologies.

RESULTS

The predominantly solid lesions were marginally more frequent in LGSCs than in SBTs (43% vs. 8%, p = 0.057). All predominantly cystic LGSCs were multilocular cystic lesions with mural nodules. Predominantly solid LGSCs exhibited pure solid masses in 2 of 3 and solid masses with intratumoral cysts in 1 of 3. Papillary growth pattern with internal branching was observed only in 18 of 25 SBTs. Signal intensity ratio on T2-weighted images (4.48 ± 1.55 vs. 8.40 ± 3.53, p < 0.01) and apparent diffusion coefficient (ADC) values (1.12 ± 0.21 vs. 1.73 ± 0.27 × 10^-3 mm²/s, p < 0.01) of solid components was significantly lower in LGSCs than in SBTs.

CONCLUSION

Compared with SBTs, lower signal intensity on T2-weighted images and lower ADC values were characteristic features of solid components in LGSCs. Papillary growth pattern with internal branching was not observed in LGSCs.

[Borderline Ovarian Tumours: CNGOF Guidelines for Clinical Practice - Imaging]

OBJECTIVE

To determine the place of imaging and the performance of different imaging techniques (transvaginal ultrasound with or without Doppler, scoring, CT, MRI) to differentiate benign tumour, borderline ovarian tumour (BOT) and malignant ovarian tumor. Differentiate the histological subtypes of BOT (serous, sero-mucinous, mucinous) and prediction in imaging of the possibility of conservative treatment.

METHODS

The research was carried out over the last 16 years using the terms "MeSH" based on the query of the Medline® database and supplemented by the review of references contained in the meta-analyzes, systematic reviews and original articles included.

RESULTS

Endo-vaginal and suprapubic ultrasonography is recommended for analysis of an ovarian mass (grade A). In the case of ultrasound by a referent, subjective analysis is the recommended technique (grade A). In case of echography by a non-referent, the use of "Simple Rules" is recommended (grade A) and should be best combined with subjective analysis to rejoin the performance of a sonographer refer (grade A). In cases of undetermined ovarian lesions in endovaginal ultrasound and suprapubic ultrasound, it is recommended to perform a pelvic MRI (grade A). The MRI protocol should include T2, T1, T1 sequences with fat saturation, diffusion, injected dynamics, and after gadolinium injection (grade B). To characterize an MRI-adnexal image, it is recommended to include a risk score for malignancy (ADNEX-MR/O-RADS) (grade C) in the report and to formulate an anatomopathological hypothesis (Grade C). The predictive signs of benignity in front of a cyst with endocystic vegetations are the low number, the small size, the presence of calcifications and the absence of Doppler flow in case of size greater than 10mm in echography (LP 4) and a curve of type 1 MRI (LP4). MRI is recommended for suspicious lesions of BOT in ultrasound (grade B) or indeterminate lesions in ultrasound (grade A). There is no data to support the usefulness of CT or PET-CT for BOT. Morphological criteria in ultrasound and MRI exist to differentiate BOT from invasive tumors regardless of grade (NP 2). Pelvic MRI is recommended to characterize a tumor suggestive of ultrasound BOT (grade C). No recommendations can be made about the use of combined ultrasound, biological, and menopausal status scores for the diagnosis of BOT. The diagnostic performance of imaging to detect peritoneal implants of BOT is not known. The assessment of the invasiveness of peritoneal implants of imaging BOT has not been evaluated. The association of macroscopic signs in MRI makes it possible to differentiate the different subtypes - serous, sero-mucinous and mucinous (intestinal type) - of BOT, despite the overlap of certain presentations (LP3). The analysis of macroscopic MRI signs must be performed to differentiate the different subtypes of TFO (grade C). No recommendation can be made on imaging prediction of the possibility of conservative BOT treatment.

A diagnostic challenge of seromucinous borderline tumor: A case report

INTRODUCTION

Magnetic resonance (MR) relaxometry provides a noninvasive predictive tool to discriminate between benign ovarian endometrioma (OE) and endometriosis-associated ovarian cancer (EAOC). Transverse relaxation rate R2 value was determined using a single-voxel, multi-echo MR sequence (HISTO) by a 3T-MR system. R2 with cutoff value of 12.1 s was established to discriminate between benign and malignant tumors.

PATIENT CONCERNS

We present a case of a 39-year-old woman who was initially thought to be malignant transformation of endometriosis by diagnostic MR imaging of the vascularized solid components.

DIAGNOSIS

A R2 value of 42.62 s on MR relaxometry demonstrated that this case is non-malignant.

INTERVENTIONS

To confirm the diagnose, left salpingo-oophorectomy by laparoscopic surgery was performed.

OUTCOMES

Histopathological results revealed seromucinous borderline tumor (SMBT). Our experience suggests that preoperative MR relaxometry may be useful for discriminating "borderline (SMBT)" from "malignancy (EAOC)." Furthermore, immunohistochemical studies of this case demonstrated ovarian SMBT cells were positive for estrogen receptor, progesterone receptor, and hepatocyte nuclear factor-1beta. A similar expression pattern was also observed in patients with benign OE.

LESSONS

In many respects, SMBT characteristics differ from those of EAOC but resemble those of benign OE. MR relaxometry unveils a new clinical approach as an adjunctive modality for discriminating SMBT from EAOC.