Frozen Section Diagnosis of Ovarian Epithelial Tumors: Diagnostic Pearls and Pitfalls

Intraoperative frozen section evaluation of ovarian sex cord-stromal tumours and their mimics: a study of 121 cases with emphasis on potential diagnostic pitfalls

Ovarian sex cord-stromal tumours (SCSTs) present diagnostic difficulties during frozen section (FS) consultations due to their diverse morphology. This study aimed to evaluate the accuracy of FS evaluation of SCSTs in our institution, as well as to examine the reasons leading to incorrect FS diagnosis. Cases mimicking SCSTs and diagnosed as such during FS were also highlighted. We analysed 121 ovarian SCST cases and their mimics which underwent FS consultations over a 10-year period, to evaluate FS accuracy, reasons for deferrals and discrepancies. FS diagnoses were concordant, deferred and discrepant compared to the final diagnosis in 50 (41.3%), 39 (32.2%) and 32 (26.5%) cases, respectively. Major discrepancies (9/121, 7.4%) were mostly related to the diagnosis of adult granulosa cell tumour (AGCT). A fibromatous AGCT was misinterpreted as fibroma on FS, while a cystic AGCT was called a benign cyst. Conversely, a mesonephric-like adenocarcinoma, a sertoliform endometrioid carcinoma and a thecoma were misinterpreted as AGCT on FS. Another discrepant case was a Krukenberg tumour with prominent fibromatous stroma in which malignant signet ring cells were overlooked and misinterpreted as fibroma. Minor discrepancies were primarily associated with fibroma (21/23, 91.3%), wherein minor but potentially impactful details such as cellular fibroma and mitotically active cellular fibroma were missed due to sampling issues and misinterpretation as leiomyoma. FS evaluation for ovarian SCSTs demonstrated an overall accuracy of 78.5%, 81.0% and 81.8% for benign, uncertain/low malignant potential and malignant categories, respectively. There was no FS-related adverse clinical impact in all cases with available follow-up information (120/121 cases). Intraoperative FS evaluation of ovarian SCSTs is challenging. A small number of cases were misinterpreted, with AGCTs being the primary group where errors occur. Awareness of common diagnostic pitfalls and difficulties, alongside application of a stepwise approach, including (1) obtaining comprehensive clinical information, (2) thorough macroscopic examination and directed sampling, (3) meticulous microscopic examination with consideration of pitfalls and mimics, (4) effective communication with surgeons in difficult cases, and (5) consultation of subspecialty colleagues in challenging cases, will enhance pathologists' reporting accuracy and management of such cases in the future.

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.

Intraoperative frozen section in gynaecology cancers with special reference to ovarian tumours: time to "unfreeze" the pitfalls in the path of the Derby horse of Oncology

PURPOSE

In an oncological set up the role of frozen section biopsy is undeniable. They serve as an important tool for surgeon's intraoperative decision making but the diagnostic reliability of intraoperative frozen section may vary from institute to institute. The surgeon should be well aware of the accuracy of the frozen section reports in their setup to enable them to take decisions based on the report. This is why we had conducted a retrospective study at Dr B. Borooah Cancer Institute, Guwahati, Assam, India to find out our institutional frozen section accuracy.

METHODS

The study was conducted from 1st January 2017 to 31st December 2022 (5 years). All gynaecology oncology patients who were operated on during the study period and had an intraoperative frozen section done were included in the study. Patients who had incomplete final histopathological report (HPR) or no final HPR were excluded from the study. Frozen section and final histopathology report were compared and analysed and discordant cases were analysed based on the degree of discordancy.

RESULTS

For benign ovarian disease, the IFS accuracy, sensitivity and specificity are 96.7%, 100% and 93%, respectively. For borderline ovarian disease the IFS accuracy, sensitivity and specificity are 96.7%, 80% and 97.6%, respectively. For malignant ovarian disease the IFS accuracy, sensitivity and specificity are 95.4%, 89.1% and 100%, respectively. Sampling error was the most common cause of discordancy.

CONCLUSION

Intraoperative frozen section may not have 100% diagnostic accuracy but still it is the running horse of our oncological institute.

A preoperative nomogram incorporating CT to predict the probability of ovarian clear cell carcinoma

OBJECTIVES

To evaluate clinical, laboratory, and radiological variables from preoperative contrast-enhanced computed tomography (CECT) for their ability to distinguish ovarian clear cell carcinoma (OCCC) from non-OCCC and to develop a nomogram to preoperatively predict the probability of OCCC.

METHODS

This IRB-approved, retrospective study included consecutive patients who underwent surgery for an ovarian tumor from 1/1/2000 to 12/31/2016 and CECT of the abdomen and pelvis ≤90 days before primary debulking surgery. Using a standardized form, two experienced oncologic radiologists independently analyzed imaging features and provided a subjective 5-point impression of the probability of the histological diagnosis. Nomogram models incorporating clinical, laboratory, and radiological features were created to predict histological diagnosis of OCCC over non-OCCC.

RESULTS

The final analysis included 533 patients with surgically confirmed OCCC (n = 61) and non-OCCC (n = 472); history of endometriosis was more often found in patients with OCCC (20% versus 3.6%; p < 0.001), while CA-125 was significantly higher in patients with non-OCCC (351 ng/mL versus 70 ng/mL; p < 0.001). A nomogram model incorporating clinical (age, history of endometriosis and adenomyosis), laboratory (CA-125) and imaging findings (peritoneal implant distribution, morphology, laterality, and diameter of ovarian lesion and of the largest solid component) had an AUC of 0.9 (95% CI: 0.847, 0.949), which was comparable to the AUCs of the experienced radiologists' subjective impressions [0.8 (95% CI: 0.822, 0.891) and 0.9 (95% CI: 0.865, 0.936)].

CONCLUSIONS

A presurgical nomogram model incorporating readily accessible clinical, laboratory, and CECT variables was a powerful predictor of OCCC, a subtype often requiring a distinctive treatment approach.

Clinical Value of Combined Multi-Indicator Tests in Diagnosis of Benign Ovarian

Background

To investigate the existence and degree of correlation between benign ovarian tumors and physiological indicators such as reproductive hormones and tumor markers.

Methods

A total of 150 patients with benign ovarian tumors admitted to Jiaxing First Hospital between January 1, 2019, and May 30, 2021, were enrolled as research subjects, while 104 healthy women were enrolled in the control group. Comparative analysis of the correlation between the reproductive hormones LH, FSH, T, E2, and the tumor indicators AMH, AFP, CEA, CA125, and CA199 between the groups was performed.

Results

There was no statistical difference in LH, FSH, T, AMH, and CEA expression levels between the experimental and control groups (p≥0.05); E₂, CA125, and CA199 levels were higher significantly in the experimental group than in the control group (P<0.001); AFP levels were significantly lower in the experimental group than in the control group (P<0.05). CA125 (0.762) had the highest AUC when diagnosing the value of each index of E2, CA125, and CA199 for benign ovarian tumors. CA125 had the highest sensitivity (56.7%), followed by E₂ (50.0%); CA199 had the highest specificity (84.5%), followed by CA125 (83.7%). The combined diagnosis of benign ovarian tumors was performed using different combinations of the indicators. When the two indicators were combined for diagnosis, the combination of E2 + CA199 had the highest sensitivity (82.6%), whereas the combination of CA125 + CA199 had the largest AUC (0.783) and the highest specificity (86.4%). The combined diagnosis of E₂+CA125+CA199 had a higher AUC than the combined diagnosis of the two indicators (0.805), with a sensitivity of 77.2%, and a specificity of 70.9%.

Conclusion

The most relevant factors for benign ovarian tumors are E2, CA125, and CA199 and the combination of these three indicators has the highest AUC for disease prediction while increasing the detection rate of benign ovarian tumors.

Concordance of Frozen Section Diagnosis of Epithelial Ovarian Neoplasm and Discussing the Diagnostic Pitfalls: An Institutional Experience

Background  Ovarian neoplasm is the third most common malignancy in Indian women. Intraoperative diagnosis becomes the critical guiding tool for the surgeons to take the decisions on the extent of surgery specially when preserving fertility has to be considered. Aims and Objective  The aim of this study is to evaluate the concordance of intraoperative diagnosis of frozen section (IFS) of ovarian epithelial neoplasm at our institute and to review and discuss the diagnostic pitfalls along with the review of literature. Materials and Methods  Data were archived from departmental record and the detailed clinical data of the patients were retrieved from hospital record system. The discordant cases were reviewed again in an attempt to address the pitfalls. Statistical Analysis  Diagnostic accuracy, sensitivity, specificity, and positive and negative predictive value of IFS of ovarian neoplasm were analyzed. Results  The overall frozen section diagnosis was concordant with final histopathology in 36 out of 44 cases (81%). The sensitivity of IFS diagnosis was found to be 100% for benign and borderline tumors, whereas 88.9% for malignant epithelial tumors, but the correctness of diagnosis is high only for benign and malignant tumors (high positive predictive value) in compared with borderline ones. The diagnostic pitfalls were identified individually in discordant cases. Conclusion  An accurate interpretation of IFS in ovarian epithelial malignancy can be achieved in benign and malignant cases, but limited in borderline tumors. Awareness of the artifacts and the limitations in mind and the IFS diagnosis can be of great help for proper management of the ovarian neoplasm.

Rapid and sensitive detection of ovarian cancer biomarker using a portable single peak Raman detection method

Raman spectroscopy (RS) is a widely used non-destructive technique for biosensing applications because of its ability to detect unique ‘fingerprint’ spectra of biomolecules from the vibrational bands. To detect these weak fingerprint spectra, a complex detection system consisting of expensive detectors and optical components are needed. As a result, surface enhanced Raman spectroscopy (SERS) method were used to increase the Raman signal multifold beyond 10¹² times. However, complexity of the entire Raman detection system can be greatly reduced if a short wavelength region/unique single spectral band can distinctly identify the investigating analyte, thereby reducing the need of multiple optical components to capture the entire frequency range of Raman spectra. Here we propose the development of a rapid, single peak Raman technique for the detection of epithelial ovarian cancers (EOC)s through haptoglobin (Hp), a prognostic biomarker. Hp concentration in ovarian cyst fluid (OCF) can be detected and quantified using Raman spectroscopy-based in vitro diagnostic assay. The uniqueness of the Raman assay is that, only in the presence of the analyte Hp, the assay reagent undergoes a biochemical reaction that results in product formation. The unique Raman signature of the assay output falls within the wavenumber region 1500–1700 cm⁻¹ and can be detected using our single peak Raman system. The diagnostic performance of our Raman system had 100.0% sensitivity, 85.0% specificity, 100.0% negative predictive value and 84.2% positive predictive value when compared to gold standard paraffin histology in a proof-of-concept study on 36 clinical OCF samples. When compared to blood-based serum cancer antigen 125 (CA125) levels, the Raman system-based assay had higher diagnostic accuracy when compared to CA125, especially in early-stage EOCs.

Pathologic Classification of Ovarian Cancer

Optimal use of human tissue for research requires an understanding of basic pathologic principles. Given that the physical assessment of tissue must occur as part of standard clinical examination, it cannot be handled directly by investigators unless they are also a part of the care team. The purpose of this chapter is to provide an overview of the clinical analytic process, from initial gross handling to histologic examination by light microscopy and the use of ancillary studies, in order to provide context for samples that are used in research and to highlight specific considerations that are relevant for obtaining appropriate tissue for experimental purposes. Given that they comprise >95% of ovarian malignancies, there is an emphasis on epithelial tumors.

Immunohistochemistry in gynecologic carcinomas: Practical update with diagnostic and clinical considerations based on the 2020 WHO classification of tumors

This review provides an update on immunohistochemistry applications-diagnostic, prognostic, and predictive-in the pathology evaluation of gynecologic carcinomas. The 5th edition of the WHO Classification of Female Genital Tumors introduced important changes in the diagnostic classification of lower genital tract, endometrial, and ovarian carcinomas, with major influence on the routine pathology practice. Lower genital tract carcinomas and their precursor lesions are now classified based on their human papillomavirus (HPV)-associated and HPV-independent pathogenesis, reflecting the clinically significant prognostic differences and impacting the therapeutic decision-making. Immunohistochemical markers have an increasing role in the pathology evaluation of endometrial carcinomas: in addition to their traditional use in the differential diagnosis and histologic subtyping, they have also been recently advocated for prognostic classification as surrogates for the TCGA (The Cancer Genome Atlas) molecular groups. New entities - mesonephric-like adenocarcinoma and gastric (gastrointestinal)-type mucinous adenocarcinoma of the endometrium - have also been added and often require immunostains for diagnostic confirmation. Ovarian carcinomas frequently show overlapping morphologic patterns and heterogeneous appearance within the same tumor, necessitating immunohistochemical work-up. Beyond diagnostic applications, there is increasing clinical demand for screening of inherited cancer syndromes, prediction of prognosis and guiding targeted therapy. Practical issues and pitfalls related to mismatch repair protein immunohistochemistry, HER2, and PD-L1 testing are also discussed.

Borderline ovarian tumor frozen section diagnoses with features suspicious of invasive cancer: a retrospective study

Background

A frozen section diagnosis of a borderline ovarian tumor with suspicious features of invasive carcinoma (“at least borderline” or synonymous descriptions) presents us with the dilemma of whether or not to perform a full ovarian cancer staging procedure. Quantification of this dilemma may help us with the issue of this clinical decision. The present study assessed and compared both the prevalence of straightforward borderline and “at least borderline” frozen section diagnoses and the proportion of these women with a final histopathological diagnosis of invasive carcinoma, with a special interest in histologic subtypes.

Methods

A retrospective cohort study was performed in three hospitals in The Netherlands. All women that underwent ovarian surgery with perioperative frozen section evaluation in one of these hospitals between January 2007 and July 2018 were identified and included in case of a borderline or “at least borderline” frozen section diagnosis and a borderline ovarian tumor or invasive carcinoma as a final diagnosis.

Results

A total of 223 women were included, of which 41 women (18.4%) were diagnosed with “at least borderline” at frozen section. Thirteen of forty-one women (31.7%) following “at least borderline” frozen section diagnosis and 14 of 182 women (7.7%) following a straightforward borderline frozen section diagnosis were diagnosed with invasive carcinoma at paraffin section evaluation (p < 0.001). When compared to straightforward borderline frozen section diagnoses, the proportion of women diagnosed with invasive carcinoma increased from 3.1 to 35.7% for serous tumors (p = 0.001), 10.0 to 21.7% for mucinous tumors (p = 0.129) and 50.0 to 75.0% (p = 0.452) in case of other histologic subtypes following an “at least borderline” frozen section diagnosis.

Conclusions

Overall, when compared to women with a decisive borderline frozen section diagnosis, women diagnosed with “at least borderline” frozen section diagnoses were found to have a higher chance of carcinoma upon final diagnosis (7.7% vs 31.7%). Especially in the serous subtype, full staging during initial surgery might be considered after preoperative consent to prevent a second surgical procedure or chemotherapy in unstaged women. Further studies are needed to evaluate whether additional sampling in case of an “at least borderline” diagnosis may decrease the risk of surgical over-treatment.

Comparison of Frozen and Permanent Section Diagnosis in Ovarian Neoplasms: Analysis of Factors Affecting Accuracy

Ovarian cancer is the seventh most common form of cancer among women worldwide. The aim of the study was to determine the accuracy of a frozen section and the factors affecting the accuracy of frozen diagnosis of ovarian neoplasms. This retrospective, cross-sectional study was conducted on 401 patients with ovarian masses with frozen section diagnosis in Shahid Faghihi Hospital affiliated to Shiraz University of Medical Sciences between 2014 and 2018. Each ovarian tumor sample was evaluated for histopathologic diagnosis using frozen and paraffin-embedded sections, which were reviewed by an expert gynecologic pathologist. Accuracy and diagnostic values were estimated by comparing the results of the 2 techniques, using the paraffin section as the gold standard. The overall accuracy of the frozen section was 94.5%. Its sensitivity was 85.3% for malignant, 88.2% for borderline, and 99.6% for benign tumors. Its specificity was also 99.7% for malignant, 98.0% for borderline, and 90.9% for benign tumors. The positive predictive value was 98.9% for malignant, 86.5% for borderline, and 94.6% for benign tumors. Most false negatives occurred in mucinous and borderline tumors. The sensitivity of malignant tumors of germ cell and sex cord-stromal cell types were 64.3% and 95.5%, respectively. The specificity of germ cell and sex-cord stromal tumors were 100% and 93.8%, respectively. Frozen section seems to be a precise technique for histopathologic diagnosis of ovarian tumors. However, borderline and mucinous tumors are the most problematic issues during frozen section diagnosis and malignant germ cell tumors have the lowest sensitivity.

Factors Influencing the Discordancy Between Intraoperative Frozen Sections and Final Paraffin Pathologies in Ovarian Tumors

Aim

To retrospectively investigate the pre-operative clinical factors and ultrasonographic features that influence the accuracy of the intraoperative frozen section (IFS) of ovarian tumors.

Patients and methods

Women with ovarian tumors that underwent IFS in one tertiary medical center were recruited from January 2010 to December 2018. Demographic and clinical data of these women were retrieved from medical records in the hospital's centralized database.

Results

A total of 903 ovarian tumors were enrolled, including 237 (26.2%) benign, 150 (16.6%) borderline tumor, and 516 (57.2%) malignant. The overall accuracy of IFS among all specimens was 89.9%. The sensitivities of IFS in diagnosing borderline tumors (82.0%) and malignant tumors (88.2%) were lower than in diagnosing benign tumors (98.7%, p <0.001, Z-test). The specificity of diagnosing malignant tumors (99.7%) was significantly higher than that of diagnosing benign tumors (94.7%, p <0.001, Z-test). The group with discordant IFS and final paraffin pathology (FPP) had younger age (47.2 ± 14.0 vs. 51.5 ± 11.8 years, p = 0.013, Mann-Whitney U test), and higher percentage of early-stage disease (85.2% vs. 65.1%, p = 0.001, chi-square test) and mucinous (39.3% vs. 3.3%) and endometrioid histologic types (34.4% vs. 20.2%) than the concordant group (all by chi-square test). Menopause (OR 0.34, 95% CI 0.15-0.76, p = 0.009), multicystic tumor in ultrasound (OR 2.14, 95% CI 1.14-4.01, p = 0.018), and ascites existence (OR 0.33, 95% CI 0.14-0.82, p = 0.016) were factors related to the discordant IFS by multivariate analysis.

Conclusions

IFS has good accuracy in the diagnosis of ovarian tumors. We recommend more frozen tissue sampling for sonographic multicystic tumors in premenopausal women to improve the accuracy of IFS.

Factors associated with the inconsistent diagnosis between frozen section and permanent pathologic examination in borderline ovarian tumors

AIM

The predictive accuracy of frozen sections for borderline ovarian tumors (BOTs) is suboptimal. The aim of this study was to determine the diagnostic accuracy of BOTs and factors associated with an upgrade to a permanent pathological diagnosis of invasive carcinoma in patients diagnosed with BOTs by frozen section.

METHODS

We conducted a retrospective study between 2011 and 2018 at Kaohsiung Chang Gung Memorial Hospital (KCGMH). Two hundred and twenty-five records of eligible patients with a diagnosis of BOT by frozen section or permanent diagnosis were reviewed. Positive predictive value and the diagnostic accuracy of frozen sections were calculated. Univariate and multivariate analyses were used to determine the clinicopathological factors associated with an upgrade of the diagnosis from a borderline tumor to malignancy.

RESULTS

The agreement between frozen section and permanent pathological diagnoses was 63.1%, and the positive predictive value was 72.1%. The multivariate analysis revealed that CA-125 level > 136 U/mL (odds ratio [OR] = 2.96, 95% confidence interval [CI] = 1.3-6.9; p = 0.012), and tumor histologic type (clear cell/endometrioid vs. mucinous; OR:32.8, 95% CI = 6.9-154.8, p < 0.001; clear cell/endometrioid vs. serous: OR 48.1, 95% CI = 8.8-261.8, p < 0.001) were independent risk factors for an upgrade of the permanent diagnosis from a BOT to ovarian carcinoma.

CONCLUSION

An elevated CA-125 level (over 136 U/mL) and tumor histologic type (clear cell and endometrioid subtypes) were associated with an upgrade in the diagnosis of ovarian tumor from a BOT on frozen section to a permanent diagnosis of malignancy.

Implementation of Mass Spectrometry Imaging in Pathology: Advances and Challenges

Mass spectrometry imaging (MSI) combines the excellence in molecular characterization of mass spectrometry with microscopic imaging capabilities of hematoxylin- and eosin-stained samples, enabling the precise location of several analytes in the tissue. Especially in the field of pathology, MSI may have an impactful role in tumor diagnosis, biomarker identification, prognostic prediction, and characterization of tumor margins during tumor resection procedures. This article discusses the recent developments in the field that are paving the way for this technology to become accepted as an analytical tool in the clinical setting, its current limitations, and future directions.

Accuracy of imprint cytology and frozen section histology for intraoperative diagnosis of ovarian epithelial tumors: A comparative study and proposed algorithm

BACKGROUND

Appropriate surgical treatment of epithelial ovarian tumors is reliant on intraoperative diagnosis. A retrospective study to compare the diagnostic accuracies of imprint cytology (IC) with frozen section histology (FSH) in these tumors was performed.

METHODS

About 78 cases of IC-based and FSH-based diagnoses against the final histopathologic diagnoses in terms of both histologic subtype (serous, mucinous, endometrioid, or clear cell tumor) and behavioral type (benign, borderline, or malignant) were compared. The cytomorphologic features of the tumor cells (nuclear atypia, papillary clusters, adenoma cells, and necrosis) in relation to behavioral types were also evaluated.

RESULTS

While the diagnostic accuracy of IC and FSH were similar with respect to behavioral type (87% and 88%, respectively), the diagnostic accuracy of IC was superior to that of FSH with respect to histologic subtype (83% and 74%, respectively). Among histopathologically confirmed malignant tumors, the diagnostic accuracy of IC (62/64; 97%) was superior to that of FSH (58/64; 91%). The presence of necrosis and absence of adenoma cells were significantly more prevalent among malignant group than among borderline and benign groups (P < .01, for both).

CONCLUSION

Since the presence of necrosis and absence of adenoma cells around the carcinoma cells appear useful in distinguishing malignant and borderline tumors, it was proposed to include IC for further intraoperative assessment of any tumors initially diagnosed as a borderline tumor by FSH.

Frozen section diagnosis of borderline ovarian tumors with suspicious features of invasive cancer is a devil's dilemma for the surgeon: A systematic review and meta-analysis

Introduction

Frozen section diagnoses of borderline ovarian tumors are not always straightforward and a borderline frozen section diagnosis with suspicious features of invasive carcinoma (reported as “at least borderline” or synonymous descriptions) presents us with the dilemma of whether or not to perform a full surgical staging procedure. By performing a systematic review and meta‐analysis, the prevalence of straightforward borderline and “at least borderline” frozen section diagnoses, as well as proportion of patients with a final diagnosis of invasive carcinoma in these cases, were assessed and compared, as quantification of this dilemma may help us with the issue of this clinical decision.

Material and methods

PubMed, EMBASE and Cochrane library databases were searched and studies discussing “at least borderline” frozen section diagnoses were included in the review. Numbers of specific frozen section diagnoses and subsequent final histological diagnoses were extracted and pooled analysis was performed to compare the proportion of patients diagnosed with invasive carcinoma following borderline and “at least borderline” frozen section diagnoses, presented as risk ratio and risk difference with 95% confidence intervals (95% CI).

Results

Of 4940 screened records, eight studies were considered eligible for quantitative analysis. A total of 921 women was identified and 230 (25.0%) of these women were diagnosed with “at least borderline” ovarian tumor at the time of frozen section. Final histological diagnoses were reported in five studies, including 61 women with an “at least borderline” diagnosis and 290 women with a straightforward borderline frozen section diagnosis. Twenty‐five of 61 women (41.0%) of the “at least borderline” group had invasive cancer at final diagnosis, compared with 28 of 290 women (9.7%) of the straightforward borderline frozen section group (risk difference −0.34, 95% CI −0.53 to −0.15; relative risk 0.25, 95% CI 0.13–0.50).

Conclusions

Women diagnosed with “at least borderline” frozen section diagnoses were found to have a higher chance of carcinoma upon final diagnosis when compared with women with a straightforward borderline frozen section diagnosis (41.0% vs 9.7%). Especially in the serous subtype, and after preoperative consent, full staging during initial surgery might be considered in these cases to prevent a second surgical procedure.

Diagnostic Accuracy of Intraoperative Frozen Section Analysis in Correlation with Histopathological Diagnosis of Ovarian Tumors in a Tertiary Care Center - A Retrospective Study

Treatment plan for ovarian neoplasms differs for benign, borderline and malignant tumors. With a turnaround time of 15-20 minutes, frozen section has become a reliable intraoperative diagnostic tool. The aim of this study is to correlate the frozen section diagnosis with subsequent histopathologic diagnosis and determine the accuracy of frozen section diagnosis. The study included 152 ovarian tumors, the overall accuracy of frozen section in diagnosing malignancy was 99.34%, whereas that for benign and borderline tumors were 97.37% and 96.71% respectively. However, the accuracy, sensitivity and specificity for borderline tumors and mucinous tumors were found to be low.

Diagnostic Discordance in Intraoperative Frozen Section Diagnosis of Ovarian Tumors: A Literature Review and Analysis of 871 Cases Treated at a Japanese Cancer Center

BACKGROUND

This study examined the accuracy and pitfalls associated with frozen section diagnosis of primary ovarian tumors and ovarian metastases based on the 2014 World Health Organization classification (WHO) criteria and proposed improvements from a pathologist's perspective.

METHODS

We microscopically reviewed 871 cases of primary ovarian tumor (N = 802) and ovarian metastasis (N = 69) and compared the results of frozen sections with the final diagnosis. Malignant potential concordance (benign, borderline, or malignant) and specific discordant diagnosis rates were analyzed. Finally, we conducted a unique literature review of specific diagnostic errors in the frozen section diagnosis of primary ovarian tumors.

RESULTS

Of 802 primary ovarian tumors, 50 (6.2%) cases showed discordant diagnoses in which mucinous carcinoma (40.5%), low-grade serous carcinoma (LGSC; 31.3%), and mucinous borderline tumor (18.4%) were frequently misinterpreted. Of 69 ovarian metastases, all 4 cases of low-grade appendiceal mucinous neoplasm (LAMN) were misdiagnosed as primary ovarian mucinous tumor. A literature review revealed that mucinous/serous borderline tumor or carcinoma accounted for approximately 70% of 217 reported discordant diagnoses.

CONCLUSION

In the present study, the concordance rate of malignant potential of the tumor was comparable to that previously reported. Even in the 2014 WHO classification, primary ovarian mucinous borderline tumor/carcinoma and LGSC still comprised the majority of discordant cases. Grossing methods that reduce sampling error are required. LAMN was frequently misinterpreted as a benign or borderline ovarian mucinous tumor. To prevent this error, a differential algorithm integrating clinical information and gross findings should be developed.

Multiparametric MRI Evaluation of Complex Ovarian Masses

OBJECTIVE

To assess the role of diffusion-weighted imaging and dynamic contrast-enhanced magnetic resonance imaging in the categorization of complex ovarian masses into benign and malignant.

MATERIALS AND METHODS

This prospective study was done on 33 complex ovarian masses. T1 and T2-weighted sequences, diffusion-weighted imaging, apparent diffusion coefficient, and dynamic contrast-enhanced magnetic resonance imaging were performed on 1.5 T MRI. Time-intensity curves, tissue signal intensity on unenhanced T1 images (SI₀), maximum absolute contrast enhancement (SI_max), time to reach SI_max (T_max), maximum relative SI (SI_rel = [SI_max - SI₀]/SI₀ ×100), maximum Slope (Slope_max = SI_rel/T_max ×100), and wash in rate (WIR = [SI_max - SI₀]/T_max) were calculated. Histopathological diagnosis was taken as gold standard.

RESULTS

A total of 20/33 masses were benign, 2/33 were borderline tumors, and 11/33 were malignant. Diffusion restriction was seen in all malignant masses and 13/20 benign masses. The mean apparent diffusion coefficient values showed a significant difference between malignant and benign, with 81.8% sensitivity and 63.6% specificity. Type III curve showed 100% specificity for malignant lesions. T_max and Slope_max were useful in differentiating benign and malignant masses; with T_max cut-off at 73.5 seconds having a high specificity (81.8%) and Slope_max cut-off at 0.83%/s having high sensitivity (91%) and negative predictive value (94.4%).

CONCLUSION

Multiparametric MRI confers high diagnostic accuracy in stratifying complex ovarian masses.

Abdominal Wall Clear Cell Carcinoma: Case Report of a Rare Event with Potential Diagnostic Difficulties

Clear cell carcinoma (CCC) is a well-known aggressive histological type of carcinoma, predominantly seen in ovary and endometrium. However, CCC arising in abdominal wall is a very rare event. We report a case of a 48-year-old woman with an abdominal wall mass at her cesarean section (c-section) scar, which increased in size and became painful in the last months. Radiology revealed a 7 cm mass in the right inferior rectus muscle sheath, suggestive of endometriosis. An irregular, firm mass was resected, densely adherent to the rectus muscle and pubic bone. Frozen section revealed a multicystic lesion with minimal cytologic atypia, and a benign cystic neoplasm was favored. However, permanent sections showed marked nuclear atypia, hobnail morphology, and areas of infiltrative growth within fibrous stroma. No benign endometrial glands were found, although fibrosis and hemorrhage were present. Napsin-A, racemase, and PAX-8 were positive, consistent with CCC, likely arising within a c-section endometriosis focus. Although CCC usually presents with moderate to marked nuclear atypia, it can be mild and, especially in cases with a predominant cystic pattern, create diagnostic difficulties. An endometriosis-associated malignancy should be considered in the differential with any enlarging nodule or increasing pain within an abdominal wall scar.