Joella Xiaohong Ang

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.

Comparison of Clinical Efficacy of Liquid-Based Cytology and High-Risk Human Papillomavirus Testing With Partial Genotyping in Cervical Screening of Women Below 30 Years Old

Introduction We evaluated the clinical efficacy of primary Human Papillomavirus (HPV) testing and liquid-based cytology (LBC) for cervical screening in women below 30 years old. Methods This was a retrospective analysis of data collected prospectively from women 25 years or older who attended hospital-based gynaecology clinics for cervical screening. Simultaneous high-risk HPV testing with partial genotyping and LBC testing was performed. Comparison of clinical efficacy of HPV testing and LBC was performed for routine screening discharge rate, colposcopy referral rate, and number of colposcopies needed for each CIN2+ detected. Results Of 6398 women included, 503 women (7.9%) tested positive for HPV DNA. The positivity was higher for 25-to-29 years old than for women ≥30 years old (12.6% vs 7.3%, P < .001). The rate was markedly skewed by a low rate for women ≥45 years old. Similarly, more women below 30 years old (10.6%) had abnormal LBC results compared to women ≥30 years old (6.0%). Comparing LBC and HPV testing, the observed difference was not significant for discharge rate to interval screening (89.5% vs 87.4%). A higher referral to coloscopy rate (6.6 % vs 7.8%) was observed for HPV screening but the number of colposcopies for each detected CIN2+ (5 vs 7) was not significantly different. Clinical efficacy of HPV and LBC testing was similar in comparisons of women in 5-year groupings between 25 and 44 years old. Conclusions Our data indicated that cervical screening for women between 25 and 29 years old could adopt HPV screening as the older women.