Intraoperative Frozen Section Research Articles

Incidental findings of borderline ovarian tumor or ovarian cancer - real-world data on surgical and oncological outcomes.

Centralization of ovarian cancer treatment is associated with higher rates of optimal surgery and longer survival. However, preoperative diagnosis of ovarian cancer is challenging and some diagnoses are made incidentally after surgery. This study investigated the surgical and oncological outcomes of patients with incidental findings of borderline ovarian tumors or ovarian cancer who were centralized postoperatively and treated with a two-stage surgical procedure, and compared these with those of patients with adnexal masses of suspected malignancy who were offered a single-stage surgical procedure with intraoperative frozen section in a tertiary hospital. A database of 390 patients with adnexal masses and surgical treatment at the Bern University Hospital, Switzerland was retrospectively reviewed to identify patients with borderline ovarian tumors or ovarian cancer between 2010 and 2020. Among 390 patients with adnexal masses, 223 were diagnosed with a borderline ovarian tumor or ovarian cancer. Compared with patients with suspected malignancy and a centralized single-stage surgical procedure, patients with an incidental postoperative malignancy diagnosis and a two-stage surgical procedure underwent more surgical interventions (1.3 vs. 2.1 p<.001) and had a longer time interval from diagnosis to initiation of chemotherapy (33.3 vs. 45.1 p=.005) and to completion of surgical cytoreduction (31.9 vs. 73.7 days, p<.001). However, there were no differences in the rates of complete cytoreduction (90.0% vs. 93.2%, p=.719), intraoperative (11.3% vs. 13.7%, p=.664) or postoperative (38.7% vs. 37.0%, p=.884) complication rates, and number of hospitalization days (11.1 vs. 12.0 days, p=.369). An incidental diagnosis of malignancy with postoperative referral was neither associated with an increased risk of recurrence (hazard ratio (HR) 0.8, 95% confidence interval (CI) 0.6-1.8, p=.839) nor death (HR 0.7, 95% CI 0.4-1.1, p=.113), and there was no difference in mean recurrence-free survival between the study subgroups. Although patients with incidental findings of borderline ovarian tumors or ovarian cancer treated with a two-stage surgical procedure had a longer time to completion of surgical staging and initiation of chemotherapy, our results showed no negative impact on oncological outcomes.

Frozen Section Analysis of Sentinel Nodes in Patients With Oral Squamous Cell Carcinoma

Frozen section (FS) analysis of sentinel nodes offers potential on-table diagnosis and treatment for occult metastasis in oral squamous cell cancer. Systematic analysis of FS during sentinel node biopsy has not been illuminated in the literature. To systematically review pooled data from studies using FS analysis in evaluating sentinel nodes in patients with cT1-T2 N0 oral squamous cell cancer. An academic librarian led the search of CENTRAL, CINAHL, Cochrane Database of Systematic Reviews, Embase, and MEDLINE for studies published in English between January 2000 and January 2023. Two authors independently screened cohort studies, case series, and randomized clinical trials, in which FS analysis was used to evaluate sentinel nodes in patients with cT1-T2 N0 oral squamous cell cancer. Data were extracted by 2 reviewers. Reporting quality was estimated using the Diagnostic Precision Study Quality Assessment Tool. Data analysis was performed between April and July 2023, and the meta-analysis was completed using the bivariate random-effects model. The primary outcome was the pooled sensitivity of FS sentinel node analysis. Secondary outcomes included evaluation of the FS technique, rate of occult metastasis, false-negative rate, and survival. Seventeen articles with 878 patients met the eligibility criteria. Although protocols varied, confirmatory serial step sectioning was performed in all studies. Occult metastasis was found in 263 of 878 patients (30%), and FS analysis identified 173 cases (65.8%). Following serial sectioning, an additional 90 positive results were identified, leading to 47 patients undergoing staged completion neck dissection. The pooled sensitivity of FS was 0.71 (95% CI, 0.60-0.80), the diagnostic odds ratio was 110, and the false-negative rate was 34.2%. The Cochrane Q value was 15.62 (df = 16; P = .48) and τ2 = 0.36. In this systematic review and meta-analysis, evaluated studies showed various techniques, in which pooled sensitivity reached 0.71, providing a benchmark for comparison to other 1-stop approaches. Due to the high false-negative rate of approximately one-third of patients, intraoperative FS must always be supplemented by serial sectioning. On-table diagnosis remains a key objective for sentinel node biopsy, and FS detection may be improved by standardizing protocols.

The characteristics of sinonasal inverted papilloma and recurrence factors: An analysis of 207 cases

AbstractObjectivesSinonasal inverted papilloma (IP) is a rare and benign tumor that affects the nose and sinuses. This tumor has a recurring nature and can be associated with malignancy or transform into a malignant lesion. Various factors have been proposed as potential recurrent and malignancy risk factors in sinonasal IP. This study examines some of these factors and the relationship between tumor location and recurrence and malignancy.MethodsA retrospective analysis was conducted on patients diagnosed with IP for 10 years or more, assessing the patients’ demographic statistics and intraoperative observations. Additionally, CT scan results of the patients were investigated.ResultsFinally, 207 patients with an average age of (52.0 ± 13.8) years were included in the study. A hundred and fifty‐five (74.9%) of patients were male and the most substance abuse was tobacco (72, 34.8%). Fifty‐five (26.6%) patients had a recurrence and 21 (10.2%) patients showed malignancy or dysplastic changes. The most common site of the tumor was the maxillary sinus (131, 63.3%).ConclusionsLong‐term follow‐up of IP patients is necessary due to the risk of recurrence and malignancy. The probability of recurrence was higher in cases where the tumor involved the frontal sinus or multisite attachment. Therefore, for accurate diagnosis of this tumor and complete resection of the lesion, especially in cases where achieving a free margin may be challenging, the intraoperative frozen section seems necessary.

Managing Thyroid Nodules in Brain-Dead Donors: Our Experience and a Review of the Literature.

Thyroid nodules are common findings during the diagnostic work-up in potential organ donors. A fast yet thorough assessment to rule out cancer is mandatory but their management remains heterogeneous among hospitals and the evidence in this field is scarce. We present our institutional experience and review the most recent literature on this topic. Retrospective case series and systematic review of the literature. In the years 2000-2023, 47 total thyroidectomies were performed on potential brain-dead donors. Intraoperative frozen section (FS) revealed 6 cases (13.9%) of papillary carcinoma that led to organ discarding in 3 cases (6.9%). The mean operative time of the procedures was 42.75 min and no procurement-delaying complications were registered. Total thyroidectomy with an intraoperative FS is a sound method for assessing suspicious nodules before organ harvesting. Future randomized studies comparing its performance against fine needle aspiration biopsy are needed to define the most cost-effective and time-saving strategy.

EP.07F.02 Preoperative Tumor-Derived Exosomes Enhanced the Accuracy of Identifying Spread Through Air Spaces from Intraoperative Frozen Sections

EP.07F.02 Preoperative Tumor-Derived Exosomes Enhanced the Accuracy of Identifying Spread Through Air Spaces from Intraoperative Frozen Sections

Translating the desmoplastic microenvironment of medullary thyroid cancer into surgical practice.

The tumor microenvironment often induces a scarring process known as tumor fibrosis or desmoplasia, which plays an important role in the initiation, progression, and clinical outcome of many types of cancer. This report aimed to highlight recent progress made in the field of de-escalation surgery for sporadic medullary thyroid cancer (MTC), building a bridge from basic science to current and emerging medical practice. This narrative review entails a holistic description and interpretation of the English-language literature on MTC desmoplasia. Absence of primary tumor desmoplasia on intraoperative frozen section and definitive histopathology goes hand in hand with absence of node metastases in up to one-third of patients with sporadic MTC. Patients with desmoplasia-negative MTC require no more than hemithyroidectomy for cure. Thyroid desmoplasia is a powerful predictive tissue biomarker for the intraoperative management of patients with sporadic MTC, outpacing conventional tumor classification systems that depend on definitive histopathology.

Enhancing the accuracy of preoperative and intraoperative evaluation of malignant ovarian germ cell tumors with a focus on fertility preservation in young women.

To analyze and improve the accuracy of preoperative assessment and intraoperative frozen-section analysis (FSA) for malignant ovarian germ cell tumors (MOGCTs), especially in the context of fertility preservation. A retrospective review of 48 women aged under 40 years, diagnosed with MOGCTs, and treated at Chonnam National University Hospital between July and December 2022 was conducted. The results of preoperative magnetic resonance imaging (MRI), measurement of serum tumor markers (α-fetoprotein [AFP], β-human chorionic gonadotropin, lactate dehydrogenase [LDH], cancer antigen [CA] 125, CA 19-9, CA 72-4, carcinoembryonic antigen), and intraoperative FSA were compared with the final pathology diagnosis. MRI demonstrated a sensitivity of 95.5%, whereas FSA showed a sensitivity of 72.9% for all MOGCTs. Sensitivities varied according to the subtype, but were consistently higher in MRI (100% for dysgerminoma, 88.9% for immature teratoma, 100% for endodermal sinus tumor, 100% for others). However, there were differences in FSA according to subtype (100% for dysgerminoma, 50.0% for immature teratoma, 100% for endodermal sinus tumor, 25.0% for others). Serum tumor markers also provided diagnostic insights, particularly LDH for dysgerminoma (82.4%) and AFP for immature teratoma (75.0%) and endodermal sinus tumor (100%). Preoperative MRI and serum tumor marker measurement may be effective in guiding fertility-sparing surgical decisions. MRI could outperform FSA in terms of accuracy, especially for immature teratoma.

Informing Decision-making for Transected Margin Reresection in Intraductal Papillary Mucinous Neoplasm-derived PDAC: An International Multicenter Study.

To assess the prognostic impact of margin status in patients with resected intraductal papillary mucinous neoplasms (IPMN)-derived pancreatic ductal adenocarcinoma (PDAC) and to inform future intraoperative decision-making on handling differing degrees of dysplasia on frozen section. The ideal oncologic surgical outcome is a negative transection margin with normal pancreatic epithelium left behind. However, the prognostic significance of reresecting certain degrees of dysplasia or invasive cancer at the pancreatic neck margin during pancreatectomy for IPMN-derived PDAC is debatable. Consecutive patients with resected and histologically confirmed IPMN-derived PDAC (2002-2022) from six international high-volume centers were included. The prognostic relevance of a positive resection margin (R1) and degrees of dysplasia at the pancreatic neck margin were assessed by log-rank test and multivariable Cox-regression for overall survival (OS) and recurrence-free survival (RFS). Overall, 832 patients with IPMN-derived PDAC were included with 322 patients (39%) having an R1-resection on final pathology. Median OS (mOS) was significantly longer in patients with an R0 status compared to those with an R1 status (65.8 vs. 26.3mo P<0.001). Patients without dysplasia at the pancreatic neck margin had similar OS compared to those with low-grade dysplasia (mOS: 78.8 vs. 66.8 months, P=0.344). However, high-grade dysplasia (mOS: 26.1mo, P=0.001) and invasive cancer (mOS: 25.0mo, P<0.001) were associated with significantly worse OS compared to no or low-grade dysplasia. Patients who underwent conversion of high-risk margins (high-grade or invasive cancer) to a low-risk margin (low-grade or no dysplasia) after intraoperative frozen section had significantly superior OS compared to those with a high-risk neck margin on final pathology (mOS: 76.9 vs. 26.1mo P<0.001). In IPMN-derived PDAC, normal epithelium or low-grade dysplasia at the neck have similar outcomes while pancreatic neck margins with high-grade dysplasia or invasive cancer are associated with poorer outcomes. Conversion of a high-risk to low-risk margin after intraoperative frozen section is associated with survival benefit and should be performed when feasible.

Clinicopathological Factors Associated with Lymph Node Metastasis in Oral Cavity Squamous Cell Carcinoma: A Retrospective Analysis

Abstract Background: Metastasis to regional cervical lymph nodes is an important prognostic factor for oral-cavity squamous cell carcinomas (OSCC). However, it is difficult to predict nodal metastasis in OSCC. The current study was done with an aim to find the association of various clinicopathological factors to the presence of cervical lymph node metastasis in OSCC. Materials and Methods: A retrospective analysis of hospital records from January 2020 to June 2023 was conducted in a tertiary care center. The records of 65 patients were included as per the inclusion criteria. The data were divided into two groups based on the presence or absence of neck nodal metastasis. Various factors such as tumor size, volume, depth of invasion (DOI), lymphovascular invasion, and perineural invasion were statistically compared between the study groups. Results: The oral tongue was the most common subsite (25, 38.5%), followed by buccal mucosa (18, 27.7%). The mean DOI in the group with cervical lymph node metastasis was 9.83 ± 4.83 mm, and it was significantly higher than the group without cervical lymph node metastasis (6.15 ± 4.20 mm, P = 0.004). Conclusion: DOI assessment is one of the most important preoperative assessments in the clinicoradiological assessment of OSCC cases. Further, it is recommended that in cases with DOI &gt;5 mm, the intraoperative frozen section on the nodes dissected in elective neck dissection is done for further determination of the extent of neck dissection.

Centralized prostatectomy with intraoperative NeuroSAFE margin assessment improves surgical margin control.

To investigate the surgical margin status in patients with prostate cancer who underwent robot-assisted radical prostatectomy (RARP) with intraoperative neurovascular structure-adjacent frozen-section analysis (NeuroSAFE) and evaluate differences compared to patients who underwent radical prostatectomy without NeuroSAFE. Between September 2018 and January 2021, 962 patients underwent centralized RARP with NeuroSAFE. A secondary resection was performed in case of a positive surgical margin (PSM) on intraoperative frozen section (IFS) analysis to convert a PSM into a negative surgical margin (NSM). A retrospective cohort consisted of 835 patients who had undergone radical prostatectomy in a tertiary centre without NeuroSAFE between January 2000 and December 2017. We performed multivariable logistic regression to evaluate differences in risk of PSM between cohorts after controlling for clinicopathological variables. Patients operated with NeuroSAFE in the centralized clinic had 29% PSM at a definitive pathological RP examination. The median cumulative length of definitive PSM was 1.1 mm (interquartile range: 0.4-3.8). Among 275 men with PSM, 136 (49%) had a cumulative length ≤1 mm and 198 (72%) ≤3 mm. After controlling for PSA, Grade group, cribriform pattern, pT-stage, and pN-stage, patients treated in the centralized clinic with NeuroSAFE had significantly lower odds on PSM (odds ratio [OR]: 0.70, 95% confidence interval [CI]: 0.56-0.88; P = 0.002), PSM length >1 mm (OR: 0.14, 95% CI: 0.09-0.22; P < 0.001), and >3 mm (OR: 0.21, 95% CI: 0.14-0.30; P < 0.001). This study provides a detailed overview of surgical margin status in a centralized RP NeuroSAFE cohort. Centralization with NeuroSAFE was associated with lower PSM rates and significantly shorter PSM cumulative lengths, indicating improved control of surgical margin status.

Intraoperative margin assessment during radical prostatectomy: is microscopy frozen in time or ready for digital defrost?

Intraoperative frozen section (IFS) is used with the intention to improve functional and oncological outcomes for patients undergoing radical prostatectomy (RP). High resource requirements of IFS techniques such as NeuroSAFE may preclude widespread adoption, even if there are benefits to patients. Recent advances in fresh-tissue microscopic digital imaging technologies may offer an attractive alternative, and there is a growing body of evidence regarding these technologies. In this narrative review, we discuss some of the familiar limitations of IFS and compare these to the attractive counterpoints of modern digital imaging technologies such as the speed and ease of image generation, the locality of equipment within (or near) the operating room, the ability to maintain tissue integrity, and digital transfer of images. Confocal laser microscopy (CLM) is the modality most frequently reported in the literature for margin assessment during RP. We discuss several imitations and obstacles to widespread dissemination of digital imaging technologies. Among these, we consider how the 'en-face' margin perspective will challenge urologists and pathologists to understand afresh the meaning of positive margin significance. As a part of this, discussions on how to describe, categorize, react to, and evaluate these technologies are needed to improve patient outcomes. Limitations of this review include its narrative structure and that the evidence base in this field is relatively immature but developing at pace.

MRI and frozen section evaluation of mylohyoid muscle in determining surgical approach for T2-T3 floor of the mouth cancer.

The choice of surgical approach for floor of the mouth (FOM) cancer, particularly for intermediate-stage tumors (cT2-cT3), remains controversial. This study aims to evaluate a method considering mylohyoid muscle (MM) invasion as a determinant for surgical approach selection, utilizing magnetic resonance imaging (MRI) preoperatively and frozen section (FS) analysis intraoperatively. This observational retrospective cohort study analyzed patients undergoing surgical resection of cT2 and cT3 FOM squamous cell carcinoma (SCC) between January 2013 and June 2023. MM infiltration assessed by preoperative MRI determined the surgical approach: clear infiltration led to compartmental surgery (CS), while doubtful or absent infiltration led to transoral surgery (TOS). Conversion from TOS to CS occurred intraoperatively based on macroscopic evidence or positive FS. Data collected included demographic, clinical, surgical, and pathological variables. Survival analysis was conducted using Kaplan-Meier method. Among 44 patients included, majority had cT2 tumors (59.1%). MM resection was necessary in 22.7% of cases. Overall survival (OS) and progression-free survival (PFS) did not significantly differ between TOS and CS groups. Radiological depth of invasion (rDOI) < 10mm is correlated with MM preservation in 89% of cases, while rDOI > 10mm is correlated with MM resection only in 23.8% of cases. Pathological depth of invasion (pDOI) discrepancies were observed in the two groups: in CS group is shown a higher pDOI (> 10mm) confirmation (90%). Surgical complications and functional outcomes differed between TOS and CS groups. Considering MM invasion for surgical approach selection in cT2-cT3 FOM tumors appears oncologically safe, with better functional outcomes in muscle preservation. Preoperative MRI for MM assessment combined with intraoperative FS analysis provides reliable guidance for surgical decision-making.

Agreement between frozen section and histopathology to detect malignancy in adnexal masses according to size and morphology by ultrasound.

Management of suspect adnexal masses involves surgery to define the best treatment. Diagnostic choices include a two-stage procedure for histopathology examination (HPE) or intraoperative histological analysis - intraoperative frozen section (IFS) and formalin-fixed and paraffin-soaked tissues (FFPE). Preoperative assessment with ultrasound may also be useful to predict malignancy. We aimed at determining the accuracy of IFS to evaluate adnexal masses stratified by size and morphology having HPE as the diagnostic gold standard. A retrospective chart review of 302 patients undergoing IFS of adnexal masses at Hospital de Clínicas de Porto Alegre, between January2005 and September2011 was performed. Data were collected regarding sonographic size (≤10cm or >10cm), characteristics of the lesion, and diagnosis established in IFS and HPE. Eight groups were studied: unilocular lesions; septated/cystic lesions; heterogeneous (solid/cystic) lesions; and solid lesions, divided in two main groups according to the size of lesion, ≤10cm or >10cm. Kappa agreement between IFS and HPE was calculated for each group. Overall agreement between IFS and HPE was 96.1% for benign tumors, 96.1% for malignant tumors, and 73.3% for borderline tumors. Considering the combination of tumor size and morphology, 100% agreement between IFS and HPE was recorded for unilocular and septated tumors ≤10cm and for solid tumors. Stratification of adnexal masses according to size and morphology is a good method for preoperative assessment. We should wait for final HPE for staging decision, regardless of IFS results, in heterogeneous adnexal tumors of any size, solid tumors ≤10cm, and all non-solid tumors >10cm.

The Prevalence of Sentinel Lymph Node Positivity and Implications for the Utility of Frozen Section Diagnosis Following Neoadjuvant Systemic Therapy in Patients with Clinically Node-Negative HER2-Positive or Triple-Negative Breast Cancer.

Axillary dissection is the standard of care for patients with positive sentinel lymph nodes (SLNs) following neoadjuvant systemic therapy. Frozen section can provide intraoperative information regarding the need for axillary dissection during the index operation. However, there are limited data on the utility of frozen section in patients with clinically node-negative (cN0) HER2-positive or triple-negative breast cancer. We conducted a single-institution observational cohort study including patients with non-inflammatory, cN0, HER2-positive or triple-negative breast cancer treated with neoadjuvant systemic therapy between 2015 and 2019. We estimated the prevalence of SLN positivity and the diagnostic test characteristics of SLN frozen section. Overall, 662 patients were eligible for inclusion, and 44 patients had one or more positive SLNs (prevalence: 6.6%, 95% confidence interval [CI] 4.9-8.8). There were 490 (74.0%) patients who had intraoperative frozen section, and 19 (3.9%) tested positive among 33 (6.7%) with positive final pathology. Frozen section sensitivity was 57.6% (95% CI 39.2-74.5), specificity was 100% (95% CI 99.2-100), positive predictive value was 100% (95% CI 82.4-100), and negative predictive value was 97.0% (95% CI 95.1-98.4). The sensitivity of frozen section for detection of micrometastases or isolated tumor cells was 35.3% (95% CI 14.2-61.7). In patients with cN0 HER2-positive or triple-negative breast cancer who have been treated with neoadjuvant therapy, positive SLNs are uncommon and frozen section sensitivity is modest. Decisions to defer SLN evaluation to final pathology, which may be reasonable in many settings, can be informed, in part, by these findings.

Accuracy of ultrasound, magnetic resonance imaging and intraoperative frozen section in the diagnosis of ovarian tumours: data from a London tertiary centre

BackgroundOvarian cancer has the worst prognosis among all gynaecological cancers. The pre-operative and intraoperative diagnosis of ovarian tumours is imperative to ensure the right operation is performed and to improve patients’ outcomes.MethodologyA retrospective review of cases with a confirmed histological diagnosis of ovarian cases was undertaken from January 2017 to December 2021. Comparison was undertaken between this final diagnosis and the pre-operative ultrasound, MRI and frozen section (FS) to assess diagnostic accuracy of each. In the ultrasound cases, the level of the examiner was collected. Statistical analysis was performed using Stata MP v17.0 software (USA, 2023).ResultsIn total, 156 ovarian masses were examined by FS. In the histopathological examination, 123/156 of these tumours were epithelial tumours. Pre-operative US subjective impression was made in 63/156 cases and preoperative MRI subjective impression was made in 129/156 cases. For benign, borderline and malignant tumours, FS demonstrated a sensitivity of 90.8% (95%CI:81.9–96.2), 86.8% (95%CI:71.9–95.6) and 97.6% (95%CI:87.4–99.9) respectively. Ultrasound’s sensitivities were 95.2% (95%CI:76.2–99.9), 20% (95%:4.33–48.1), 57.1% (95%CI:28.9–82.3) and MRI’s sensitivities were 100% (95%CI:80.5–100), 31.5% (95%CI:19.5–45.6) and 63.2% (95%CI:46–78.2) respectively.ConclusionsFS remains an accurate tool for diagnosing ovarian malignancy. However, across both imaging modalities and FS, the diagnosis of borderline ovarian tumours remains challenging.

An Audit of Intraoperative Frozen Section at a Tertiary Care Center

ABSTRACT Background: Frozen section (FS) is an important diagnostic tool for intraoperative decision-making. Audit of FS is an integral aspect of qualitative measure of pathology services. The aim of the study was to correlate FS diagnosis with final diagnosis and study diagnostic accuracy. Materials and Methods: The study was conducted for a period of 12 months from July 1, 2021, to June 31, 2022, at a tertiary care center. A total of 122 consecutive frozen cases were studied retrospectively. The FS and corresponding formalin-fixed paraffin-embedded tissue section with their final histopathological examination reports were studied and analyzed. The results were analyzed as concordant and discordant rates, which were compared with other similar studies. Reasons for discordance were discussed. Results: The patients were in the age range of 3 months to 87 years with a male:female ratio of 1.1:1. The turnaround time from receipt of sample to release of frozen report ranged from 10 to 40 min (average = 20 min). Indications of FS were for primary diagnosis of lesion (n = 66), resection margin assessment (n = 41), lymph node assessment (n = 12), and assessment of donor liver tissue (n = 3). Maximum number of specimens were from the surgery department, and the most commonly sampled site was oral cavity. The concordance and discordance rates were 95.90% and 4.10%, respectively. Conclusion: Intraoperative FS diagnosis aids in proper surgical decision-making and management. Periodic audit of FS and analysis of discrepancies is important to avoid mistakes in FS diagnosis.

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.

Ex Vivo Fluorescence Confocal Microscopy for Intraoperative Examinations of Lung Tumors as Alternative to Frozen Sections-A Proof-of-Concept Study.

Intraoperative frozen sections (FS) are frequently used to establish the diagnosis of lung cancer when preoperative examinations are not conclusive. The downside of FS is its resource-intensive nature and the risk of tissue depletion when small lesions are assessed. Ex vivo fluorescence confocal microscopy (FCM) is a novel microimaging method for loss-free examinations of native materials. We tested its suitability for the intraoperative diagnosis of lung tumors. Samples from 59 lung resection specimens containing 45 carcinomas were examined in the FCM. The diagnostic performance in the evaluation of malignancy and histological typing of lung tumors was evaluated in comparison with FS and the final diagnosis. A total of 44/45 (98%) carcinomas were correctly identified as malignant in the FCM. A total of 33/44 (75%) carcinomas were correctly subtyped, which was comparable with the results of FS and conventional histology. Our tests documented the excellent visualization of cytological features of normal tissues and tumors. Compared to FS, FCM was technically less demanding and less personnel intensive. The ex vivo FCM is a fast, effective, and safe method for diagnosing and subtyping lung cancer and is, therefore, a promising alternative to FS. The method preserves the tissue without loss for subsequent examinations, which is an advantage in the diagnosis of small tumors and for biobanking.

Sub-lobar resection versus lobectomy for challenging intraoperative frozen sections in lung adenocarcinoma within 3 cm

ObjectivesIntraoperative frozen section (FS) analysis is pivotal in guiding surgical interventions for early-stage lung adenocarcinoma. However, the challenge arises when distinguishing between Minimally Invasive Adenocarcinoma (MIA) and Invasive Adenocarcinoma (IAC) poses diagnostic difficulties. This study investigates the prognosis and clinicopathological characteristics of patients encountering this diagnostic challenge. MethodsWe conducted a retrospective analysis of 7,082 intraoperative FSs from early-stage lung adenocarcinoma cases. The cases with pulmonary nodules within 3cm and diagnosed as indeterminate FSs were included. We analyzed baseline data, computed tomography (CT) findings, and pathological characteristics. Prognostic data were obtained from patients with confirmed IAC diagnoses through final pathological examination. ResultsOut of 7,082 FSs, 551 cases presented challenges in distinguishing between MIA and IAC. Upon final pathological examination, 233 cases were identified as IAC, while 314 were classified as MIA. The median invasive pathological size in the IAC group was larger than that in the MIA group (0.6cm vs 0.3cm). 131 cases (56.2%) with IAC underwent lobectomy, while 102 cases (43.8%) underwent sub-lobar resection.Among the MIA cases, 220 cases (69.8%) underwent sub-lobar resection, while 95 cases (30.2%) underwent lobectomy. No recurrence and disease specific death was observed during the follow-up period, regardless of surgical strategy. ConclusionsIndeterminate intraoperative FSs, posing diagnostic challenges in distinguishing between MIA and IAC. Sub-lobar resection presented the same long term survival benefit compared with the lobectomy for indeterminate lung adenocarcinoma within 3cm during intraoperative FSs.

Malakoplakia of the Endometrium: A Rare Unexpected Disease Raising Clinical Concern for Malignancy.

Malakoplakia is a rare disease that manifests as a histiocytic inflammatory process and most often occurs in the urinary bladder. It is caused by an impaired capacity of histiocytes to kill and digest bacteria. The typical histopathologic findings are sheets of histiocytes with granular eosinophilic cytoplasm and characteristic Michaelis-Gutmann bodies, spherical bodies with a targetoid appearance. Malakoplakia is even rarer in the gynecologic tract, and our literature search found only 21 published patients of malakoplakia involving the endometrium. Here we report a 60-year-old female patient who presented with recurrent pelvic infections and postmenopausal bleeding, which raised concern for an endometrial malignancy. Hysterectomy with salpingo-oophorectomy revealed malakoplakia involving the endometrium and also the right ovary. Michaelis-Gutmann bodies were visible on the intraoperative frozen section that was performed to rule out an endometrial malignancy. We summarize the clinicopathologic findings of the published patients of endometrial malakoplakia.