Ovarian mucinous and seromucinous neoplasms: problematic aspects and modern diagnostic approach

Pseudomyxoma peritonei arising from mature ovarian teratoma, a rare entity: Report of six cases and review of current literature

Background

Pseudomyxoma peritonei (PMP) is a clinical syndrome characterised by intraperitoneal accumulation of mucus due to mucinous neoplasia. It is a rare condition affecting 1-2 per million individuals per year. The majority of PMP arises from a ruptured mucinous appendiceal tumour, with infrequent occurrences from other primary gastrointestinal tumours and mucinous ovarian tumours. PMP arising from a mature ovarian teratoma is a rare entity, with limited case reports in the literature. Given the infrequent and sporadic occurrences of these tumours, little is known about the tumour behaviour and prognosis.

Case series and literature review

Herein, we report six cases of PMP arising from a mature ovarian teratoma who were treated with primary cytoreductive surgery (CRS), with one case of recurrence. Literature review identified 21 cases from 12 manuscripts. Nineteen patients were treated with CRS alone, with two patients receiving adjuvant hyperthermic intraperitoneal chemotherapy (HIPEC). Follow up data were variably reported, with no recurrence in 20 patients during their follow up of 5-54 months. One patient reported to have died of disease at 49 months.

Conclusion

Despite the lack of high-quality evidence and limitations of small case series, our review indicates that close surveillance after CRS could be considered as the preferred treatment over more morbid CRS and HIPEC, with HIPEC reserved for patients who recur or progress after CRS.

Comparison of Benign, Borderline, and Malignant Ovarian Seromucinous Neoplasms on MR Imaging

PURPOSE

This study aimed to compare MRI findings among benign, borderline, and malignant ovarian seromucinous neoplasms.

METHODS

We retrospectively analyzed MRI data from 24 patients with ovarian seromucinous neoplasms-seven benign, thirteen borderline, and six malignant. The parameters evaluated included age, tumour size, morphology, number, height, apparent diffusion coefficient (ADC) values, T2 ratios, time-intensity curve (TIC) descriptors, and TIC patterns of the mural nodules. Additionally, we examined the T2 and T1 ratios of the cyst contents, tumour markers, and the presence of endometriosis. We used statistical tests, including the Kruskal-Wallis and Fisher-Freeman-Halton exact tests, to compare these parameters among the three aforementioned groups.

RESULTS

The cases showed papillary architecture with internal branching in 57% of benign, 92% of borderline, and 17% of malignant cases. Three or fewer mural nodules were seen in 57% of benign, 8% of borderline, and 17% of malignant cases. Compared to benign and borderline tumours, mural nodules of malignant neoplasms had significantly increased height (P = 0.015 and 0.011, respectively), lower means ADC values (P = 0.003 and 0.035, respectively). The mural nodules in malignant cases also demonstrated significantly lower T2 ratios than those in the benign cases (P = 0.045). Most neoplasms displayed an intermediate-risk TIC pattern, including 80% benign, 83% borderline, and 60% malignant neoplasms, and no significant differences were observed.

CONCLUSION

Most benign and borderline tumours exhibited a papillary architecture with an internal branching pattern, whereas this feature was less common in malignant neoplasms. Additionally, benign tumours had fewer mural nodules compared to borderline tumours. Malignant neoplasms were characterized by mural nodules with increased height and lower ADC values than those in benign and borderline tumours. Interestingly, all three groups predominantly exhibited an intermediate-risk TIC pattern, emphasizing the complexity of diagnosing seromucinous neoplasms using MRI.

Infiltrative pattern of invasion is independently associated with shorter survival and desmoplastic stroma markers FAP and THBS2 in mucinous ovarian carcinoma

AIMS

Mucinous ovarian carcinoma (MOC) is a rare ovarian cancer histotype with generally good prognosis when diagnosed at an early stage. However, MOC with the infiltrative pattern of invasion has a worse prognosis, although to date studies have not been large enough to control for covariables. Data on reproducibility of classifying the invasion pattern are limited, as are molecular correlates for infiltrative invasion. We hypothesized that the invasion pattern would be associated with an aberrant tumour microenvironment.

METHODS AND RESULTS

Four subspecialty pathologists assessed interobserver reproducibility of the pattern of invasion in 134 MOC. Immunohistochemistry on fibroblast activation protein (FAP) and THBS2 was performed on 98 cases. Association with survival was tested using Cox regression. The average interobserver agreement for the infiltrative pattern was moderate (kappa 0.60, agreement 86.3%). After reproducibility review, 24/134 MOC (18%) were determined to have the infiltrative pattern and this was associated with a higher risk of death, independent of FIGO stage, grade, and patient age in a time-dependent manner (hazard ratio [HR] = 10.2, 95% confidence interval [CI] 3.0-34.5). High stromal expression of FAP and THBS2 was more common in infiltrative MOC (FAP: 60%, THBS2: 58%, both P < 0.001) and associated with survival (multivariate HR for FAP: 1.5 [95% CI 1.1-2.1] and THBS2: 1.91 [95% CI 1.1-3.2]).

CONCLUSIONS

The pattern of invasion should be included in reporting for MOC due to the strong prognostic implications. We highlight the histological features that should be considered to improve reproducibility. FAP and THBS2 are associated with infiltrative invasion in MOC.

Ovarian tumors in the pediatric population: An update

Research reveals that 1% of neoplasms in females under 17 years of age are ovarian neoplasms and though usually benign, malignant tumors may occur in the pediatric age group. This review considers various current concepts of these tumors including the epidemiology, risk factors, clinical presentations, diagnosis, differential diagnosis, and treatment options including the need to provide fertility-sparing surgery as well as their potential impacts on the psychological well-being of children and adolescents. We gathered data from the published articles ranging from studies, meta-analyses, retrospective studies, and reviews. We focused on the articles published in English between January 1, 2000, and August 31, 2023. Only a few articles published prior to 2000 were included for historical perspective.

Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy to Treat Pseudomyxoma Peritonei of Ovarian Origin: A Retrospective French RENAPE Group Study

BACKGROUND

Ovarian pseudomyxoma peritonei (OPMP) are rare, without well-defined therapeutic guidelines. We aimed to evaluate cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) to treat OPMP.

METHODS

Patients from the French National Network for Rare Peritoneal Tumors (RENAPE) database with proven OPMP treated by CRS/HIPEC and with histologically normal appendix and digestive endoscopy were retrospectively included. Clinical and follow-up data were collected. Histopathological and immunohistochemical features were reviewed.

RESULTS

Fifteen patients with a median age of 56 years were included. The median Peritoneal Cancer Index was 16. Following CRS, the completeness of cytoreduction (CC) score was CC-0 for 9/15 (60%) patients, CC-1 for 5/15 (33.3%) patients, and CC-2 for 1/15 (6.7%) patients. The median tumor size was 22.5 cm. After pathological review and immunohistochemical studies, tumors were classified as Group 1 (mucinous ovarian epithelial neoplasms) in 3/15 (20%) patients; Group 2 (mucinous neoplasm in ovarian teratoma) in 4/15 (26.7%) patients; Group 3 (mucinous neoplasm probably arising in ovarian teratoma) in 5/15 (33.3%) patients; and Group 4 (non-specific group) in 3/15 (20%) patients. Peritoneal lesions were OPMP pM1a/acellular, pM1b/grade 1 (hypocellular) and pM1b/grade 3 (signet-ring cells) in 13/15 (86.7%), 1/15 (6.7%) and 1/15 (6.7%) patients, respectively. Disease-free survival analysis showed a difference (p = 0.0463) between OPMP with teratoma/likely-teratoma origin (groups 2 and 3; 100% at 1, 5, and 10 years), and other groups (groups 1 and 4; 100%, 66.6%, and 50% at 1, 5, and 10 years, respectively).

CONCLUSION

These results suggested that a primary therapeutic strategy using complete CRS/HIPEC for patients with OPMP led to favorable long-term outcomes.

TP53 as a Diagnostic Aid in the Distinction of Ovarian Mucinous Borderline Tumors From Mucinous Carcinoma

Ovarian mucinous borderline tumors (MBTs) are clinically managed as benign neoplasms while the management of ovarian mucinous carcinomas (MC) is dependent on tumor stage. Despite the standardization of sampling of ovarian mucinous neoplasms, limited interobserver reproducibility between MBT and MC persists. Based on our recent finding that abnormal TP53 expression is associated with unfavorable outcome in MBT, we hypothesized that TP53 status might improve the reproducible distinction of MBT from MC. A virtual slide set of 85 consecutive ovarian mucinous neoplasms received at a single institution, with each case represented by 3 full sections, were reviewed by 3 pathologists in 2 iterations. The initial assessment was based solely on morphologic review, while the second iteration was performed with knowledge of TP53 status. The reproducibility of a trinary categorization (MBT, MBT with intraepithelial carcinoma [IEC], MC) significantly improved from a κ of 0.60 based on the initial morphologic assessment to a κ of 0.76 (t-test, P =0.0042) after consideration of TP53 immunohistochemistry (IHC) results. Six out of 85 patients died of disease, and in 2 of them, at least 1 pathologist assessed MBT with IEC and not MC even after integration of TP53 IHC. With the integration of TP53 IHC, substantial interobserver agreement for MBT and MC can be reached, particularly in cases with an uncertain degree of confluent growth. TP53 IHC can also be used to highlight and support the presence of IEC in MBT, however, discordances remained in 2 cases with adverse outcome.

Macroscopic examination of gynaecological specimens: a critial and often underemphasised aspect of pathological reporting

Pathological examination of surgical specimens and compilation of a surgical pathology report comprises a series of events which includes macroscopic examination and tissue sampling, either complete or selected. This step is critical but often overlooked in the literature and not given the attention it deserves. In this review, we discuss the macroscopic examination and grossing of gynaecological pathology specimens, with reference to national and international protocols. We provide guidance as to the degree of sampling necessary in different scenarios and stress that a common-sense approach is necessary with flexibility in the degree of sampling depending on a variety of factors.

The diverse morphology and immunophenotype of ovarian endometrioid carcinomas

Endometrioid carcinoma (EC) accounts for approximately 10-12% of ovarian epithelial malignancies but compared to its relative frequency, results in a disproportionate number of diagnostically difficult cases with potential for misdiagnosis. In this review the protean and diverse morphologies of ovarian EC are discussed, including 'metaplastic' changes, EC with spindle cell differentiation/corded and hyalinised features and EC with sex cord-like formations. The propensity for 'transdifferentiation' in ovarian ECs is also discussed, one example being the association with a somatically derived yolk sac tumour. Although immunohistochemistry may be extremely useful in diagnosing EC and in distinguishing between EC and other ovarian epithelial malignancies, metastatic neoplasms and sex cord-stromal tumours, this review also discusses the propensity for ovarian EC to exhibit an aberrant immunophenotype which may compound diagnostic uncertainty. The genomic characteristics of these tumours and the recent 'incorporation' of seromucinous carcinoma into the EC category are also discussed.

Primary Mucinous Tumors of the Ovary: An Interobserver Reproducibility and Detailed Molecular Study Reveals Significant Overlap Between Diagnostic Categories

Primary ovarian mucinous tumors represent a heterogeneous group of neoplasms, and their diagnosis may be challenging. We analyzed 124 primary ovarian mucinous tumors originally diagnosed as mucinous borderline tumors (MBTs) or mucinous carcinomas (MCs), with an emphasis on interobserver diagnostic agreement and the potential for diagnostic support by molecular profiling using a next-generation sequencing targeted panel of 727 DNA and 147 RNA genes. Fourteen experienced pathologists independently assigned a diagnosis from preset options, based on a review of a single digitized slide from each tumor. After excluding 1 outlier participant, there was a moderate agreement in diagnosing the 124 cases when divided into 3 categories (κ = 0.524, for mucinous cystadenoma vs MBT vs MC). A perfect agreement for the distinction between mucinous cystadenoma/MBT as a combined category and MC was found in only 36.3% of the cases. Differentiating between MBTs and MCs with expansile invasion was particularly problematic. After a reclassification of the tumors into near-consensus diagnostic categories on the basis of the initial participant results, a comparison of molecular findings between the MBT and MC groups did not show major and unequivocal differences between MBTs and MCs or between MCs with expansile vs infiltrative pattern of invasion. In contrast, HER2 overexpression or amplification was found only in 5.3% of MBTs and in 35.3% of all MCs and in 45% of MCs with expansile invasion. Overall, HER2 alterations, including mutations, were found in 42.2% of MCs. KRAS mutations were found in 65.5% and PIK3CA mutations in 6% of MCs. In summary, although the diagnostic criteria are well-described, diagnostic agreement among our large group of experienced gynecologic pathologists was only moderate. Diagnostic categories showed a molecular overlap. Nonetheless, molecular profiling may prove to be therapeutically beneficial in advanced-stage, recurrent, or metastatic MCs.

Microscopic Sertoliform Sex Cord Proliferations: A Rare Incidental Finding Associated With Endometriosis and Ovarian Epithelial Neoplasia

Microscopic sex cord proliferations are a rare incidental finding seen in association with ovarian and uterine stromal or epithelial neoplasms and more uncommonly non-neoplastic conditions such as endometriosis and adenomyosis. They may also occur in the absence of other pathology, as an incidental finding in the ovaries of pregnant women and in heterotopic locations such as the fallopian tube. Most reports of this phenomenon describe adult granulosa cell tumor-like morphology. Herein, we describe 4 cases of microscopic sex cord proliferations with Sertoliform features, occurring in the stromal component of endometriosis or in the wall of an epithelial ovarian neoplasm; 2 of the patients with endometriosis had concurrent endometrioid adenocarcinoma (1 uterine corpus, 1 ovary). The proliferations were positive with sex cord markers inhibin and calretinin. As far as we are aware, such Sertoliform proliferations have not been reported previously in endometriosis and have only rarely been described in association with ovarian epithelial neoplasia. It is likely that such proliferations represent a benign non-neoplastic phenomenon. Awareness of this phenomenon is important in order to avoid misdiagnosis as a sex cord or other neoplasm. In reporting this unusual phenomenon, we review incidental sex cord and sex cord-like proliferations in the female genital tract.

The effect of chemotherapy in patients with stage I mucinous ovarian cancer undergoing fertility-sparing surgery

Objective

To determine the effect of adjuvant chemotherapy in patients with stage I mucinous ovarian cancer (MOC) undergoing fertility-preserving surgery.

Patients and methods

The clinicopathological characteristics and survival information of young women with stage I MOC from SEER databases between 2004 and 2019 were collected. The relationship between chemotherapy and the characteristics was examined by univariate and multivariate logistic regression analyses. Univariable and multivariate Cox proportional hazards survival analysis were employed for cancer-specific survival. Cox analysis was performed to build a nomogram model.

Results

All 901 eligible patients with stage I MOC were screened from the SEER database. There were 321(35.6%) patients aged 9-30 years, 580(64.4%) aged 31-45 years, 645 (71.6%) patients with stage IA/IB, 256 (28.4%) with stage IC disease, 411(45.6%) who underwent fertility-sparing surgery, and276(30.6%) who received postoperative adjuvant chemotherapy. Multivariate logistic regression analyses showed that postoperative chemotherapy was often used in patients aged 31-45 relative to aged 9-30 (HR: 2.215, 95%CI 1.443-3.401, P &lt; 0.001) or with grade 3 compared to grade 1 tumors (HR: 7.382, 95%CI 4.054-13.443, P &lt; 0.001) or with stage IC compared to stage IA/IB (HR: 6.436, 95%CI 4.515-9.175, P &lt; 0.001) or with non-fertility sparing surgery relative to fertility-sparing (HR:2.226, 95%CI 1.490-3.327, P &lt; 0.001). Multivariate analysis for the special population with fertility preservation indicated that patients with chemotherapy (HR: 2.905, 95% CI: 0.938-6.030, P=0.068) or with grade 3 (HR: 4.750, 95% CI: 1.419-15.896, P=0.011) had a greater risk of mortality. Significant CSS differences were observed between the non-chemotherapy and chemotherapy groups in MOC when patients were stage IA/IB-grade 2 (P=0.004) (10-year CSS rates of chemotherapy=84%, non-chemotherapy = 100%), but not when they were stage IA/IB-grade 1, stage IA/IB-grade 3 or stage IC (both P&gt;0.05). A prognostic prediction nomogram model was built for stage I MOC patient who underwent fertility-sparing and the C-index was 0.709.

Discussion

The patients aged 31-45 years, with grade 3, stage IC, and non-fertility-sparing surgery were more likely to receive adjuvant chemotherapy in the real world. For stage I MOC patient who underwent fertility-sparing surgery, the choice of chemotherapy may increase the risk of death, and it should be carefully selected in clinical practice.

The cytokeratin 17 expression in primary ovarian tumors has diagnostic but not prognostic significance

We assessed the value of cytokeratin 17 (CK17) expression for the differential diagnosis between primary ovarian mucinous tumors and metastases from the gastrointestinal tract (GIT) and the significance of CK17 expression in a broad spectrum of primary ovarian tumors with respect to their prognosis. The sample set consisted of 554 primary ovarian tumors and 255 GIT tumors. In the primary ovarian tumors, a higher CK17 expression (in > 10% of tumors cells) was present only in 0-11.4% of all tumors (including mucinous tumors, micropapillary serous borderline tumors, clear cell, endometrioid, and high-grade serous carcinomas). The only exception was low-grade serous carcinoma, where higher CK17 expression was present in 24% of cases. Concerning GIT tumors, the higher levels of CK 17 expression (in > 10% of tumor cells) were observed in the upper GIT tumors (68.5% of pancreatic ductal adenocarcinoma, 61.6% of gallbladder adenocarcinoma, and 46% of gastric adenocarcinoma), which differs substantially not only from most of the primary ovarian tumors, but also from colorectal carcinoma (3.7%; p < 0.001). The results of our study suggest that expression of CK17 can potentially be used as an adjunct marker in differential diagnosis between primary ovarian mucinous tumors and metastases from the upper GIT, but not from colorectal carcinoma. However, in GIT tumors, CK17 can be used in the differential diagnosis between adenocarcinomas of the upper and lower GIT. Statistical analysis did not reveal strong association of CK17 expression with clinicopathological variables or patient outcomes in any primary ovarian tumors.