Classifying Liver Cytology Using the WHO Reporting System: Institutional Experience and Malignancy Risk Assessment.

Recent discussions have focused on redefining noninvasive follicular variant of papillary thyroid carcinoma (NI-FVPTC) as a neoplasm rather than a carcinoma. This study assesses the potential impact of such a reclassification on the implied risk of malignancy (ROM) for the diagnostic categories of The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC). The study consisted of consecutive fine-needle aspiration biopsy (FNAB) cases collected between January 1, 2013 and June 30, 2014 from 5 academic institutions. Demographic information, cytology diagnoses, and surgical pathology follow-up were recorded. The ROM was calculated with and without NI-FVPTC and was presented as a range: all cases (ie, overall risk of malignancy [OROM]) versus those with surgical follow-up only. The FNAB cohort consisted of 6943 thyroid nodules representing 5179 women and 1409 men with an average age of 54 years (range, 9-94 years). The combined average ROM and OROM for the diagnostic categories of TBSRTC were as follows: nondiagnostic, 4.4% to 25.3%; benign, 0.9% to 9.3%; atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS), 12.1% to 31.2%; follicular neoplasm (FN), 21.8% to 33.2%; suspicious for malignancy (SM), 62.1% to 82.6%; and malignant, 75.9% to 99.1%. The impact of reclassifying NI-FVPTC on the ROM and OROM was most pronounced and statistically significant in the 3 indeterminate categories: the AUS/FLUS category had a decrease of 5.2% to 13.6%, the FN category had a decrease of 9.9% to 15.1%, and the SM category had a decrease of 17.6% to 23.4% (P < .05), whereas the benign and malignant categories had decreases of 0.3% to 3.5% and 2.5% to 3.3%, respectfully. The trend of the effect on the ROM and OROM was similar for all 5 institutions. The results from this multi-institutional cohort indicate that the reclassification of NI-FVPTC will have a significant impact on the ROM for the 3 indeterminate categories of TBSRTC.

Background:Oral lichen planus (OLP) is a relatively common chronic autoimmune disease. In the present study, we tried to correlate the histopathological criteria of WHO and modified WHO (mod.WHO) classification systems using two methods, namely, intraobserver and interobserver observations in these samples.Methods:This cross-sectional study was performed on 64 microscopic slides with the diagnosis of the OLP lesions, based on both clinical and histopathological features. At first, each pathologist individually (as intraobserver) examined microscopic slides based on both histopathologic diagnostic criteria. Later, three pathologists in a group (as interobserver) reevaluated microscopic slides 2 months later in the second phase of the study, based on both systems. Eventually, the findings were statistically analyzed with Cohen's kappa coefficient (κ) and reported.Results:According to the results, the lichen planus was detected in 8 cases using the WHO method, and in 41 cases using the Mod.WHO method. Intrarater Kappa coefficients were κ = 0.114, P = 0.299; κ = 0.181, P = 0.012; and κ = 0.062, P = 0.424 for three pathologists, respectively. The findings showed no reproducibility (κ = 0.148, P = 0.024) and there was no correlation between the two systems. Statistical analysis revealed that the histopathological criteria of the WHO classification for detecting the lichen planus microscopy were more sensitive but the Mod.WHO classification criteria were more specific for detecting the lichen planus.Conclusions:Due to the higher specificity of the histopathological criteria of Mod.WHO classification rather than WHO classification, it seems that Mod.WHO classification has more important and useful criteria for histopathological diagnosis. Finally, we can conclude that the use histopathologic criteria of the Mod.WHO classification is more useful in the diagnosis of lichen planus, although it should be in combination with clinical information.

The World Health Organization (WHO) reporting system for lung cytopathology provides a 5-tiered diagnostic framework. However, validation of the associated risk of malignancy (ROM) and clinical outcomes remains limited. This study evaluated the performance of the WHO reporting system by assessing ROM and overall survival (OS) in lung fine-needle aspiration biopsies (FNAB) specimens. A retrospective review of the institutional pathology database identified patients who underwent endobronchial ultrasound-guided transbronchial FNAB (EBUS-TBFNAB) or transthoracic CT-guided FNAB for lung lesions between January 2015 and June 2022. All cases were recategorized according to the WHO reporting system. Absolute ROM was determined by histologic and/or clinical follow-up of at least 6 months and compared with published studies that used the WHO and other international reporting systems. OS rates were analyzed across diagnostic categories. A total of 1,038 FNAB cases were included. The ROM for each WHO diagnostic category was as follows: insufficient/inadequate/non-diagnostic, 19%; benign, 9%; atypical, 33%; suspicious for malignancy, 84%; and malignant; 100%. These findings demonstrated overall concordance with prior studies, with comparatively lower ROMs in the insufficient/inadequate/non-diagnostic, benign, and atypical categories, and upper-range ROMs in the suspicious for malignancy and malignant categories. Immunocytochemistry (ICC) and molecular testing performed on available cell block materials supported tumor subtyping and therapeutic decision-making. Application of the WHO reporting system significantly improves stratification of ROM and OS across diagnostic categories in lung FNAB specimens. Inclusion of a benign category and reclassification of low-grade carcinomas as malignant enhance diagnostic precision and support optimized patient management.

Immunosuppressive Therapy and Cancer Risk in Ocular Inflammation Patients: Fresh Evidence and More Questions

Reporting of fine needle aspiration (FNA) specimens of salivary gland lesions: A comprehensive review.

Malignancy risk for the categories: Non-diagnostic, benign, atypical, suspicious, and malignant used in the categorization of endobronchial ultrasound guided-fine needle aspirates of pulmonary nodules.

Introduction to 2021 WHO Classification of Thoracic Tumors

Follow-up of indeterminate cytologic diagnoses of solid pancreatic lesions: atypia versus suspicious (one institution's experience)

S&T-39 CONCORDANCE OF URETEROSCOPIC BIOPSY GRADE TO RADICAL NEPHROURETERECTOMY GRADE AND STAGE BASED ON THE 1973 AND 2004 WHO CLASSIFICATION SYSTEMS FOR UPPER TRACT UROTHELIAL CARCINOMA

Salivary Gland Neoplasm of Uncertain Malignant Potential (SUMP) (Milan IVB) and Its Subgroups: A Multi-Institutional Analysis of Risk of Neoplasm and Malignancy.

New classification of the thyroid fine-needle aspiration biopsy (FNAB) results tries to stratify the risk of malignancy of thyroid follicular lesions using 'follicular lesion of undetermined significance' (FLUS) subcategory. Clinical significance of this category in the endemic (or post-endemic) areas has not been clearly established. The aim of the study was to determine the risk of malignancy for FLUS as well as to evaluate ultrasound (US) malignancy risk features (MRF) in such nodules in comparison with 'suspicious for neoplasm' (SFN) and 'benign lesions' (BL). The US images and cytological diagnoses of 589 thyroid follicular lesions were analysed from January 2010 to July 2012. Cytological follow-up was assessed in 110 cases and surgical one in 100 cases. FLUS was diagnosed in 340 cases (3.8% of all cytological diagnoses and 57% of thyroid follicular lesions). Altogether, clinical and/or surgical follow-up revealed thyroid cancer in 3.2% patients with FLUS nodules. Repeat FNAB led to more specific diagnosis in 74.4% of FLUS (3.5%, papillary cancers or their suspicion; 2.3%, SFN; 68.6%, BL). The histopathological examination showed thyroid cancer in 6.4% cases of FLUS and 7.0% of SFN and follicular adenoma in 8.5% of FLUS and 11.6% of SFN (NS, FLUS vs SFN). FLUS showed MRF of intermediate values between BL and SFN; SFN more often than FLUS showed at least two MRF (53 vs 30%, P<0.0001). The risk of cancer in FLUS in areas with recently corrected iodine supply is low. In such areas, repeated biopsy leads to more precise cytological diagnosis in about 3/4 cases.

Spindle cell lesions can be challenging to diagnose on cytology alone. The World Health Organization (WHO) is publishing a new WHO Reporting System for Soft Tissue Cytopathology (WHORSSTC). The authors examined the performance characteristics of spindle cell lesion diagnoses at their institution when reclassifying according to the WHORSSTC. Spindle cell fine-needle aspirations or fine-needle core biopsies diagnosed on cytology were collected from August 2021 through July 2024. Clinical information, procedural data, cytologic diagnoses, and surgical pathology diagnoses were obtained from the electronic medical records. Cases were reclassified according to the WHORSSTC, and relevant metrics were calculated. In total, 296 cases were identified from 164 women, 131 men, and one transgender female. The average age was 60 years. Biopsies were obtained as fine-needle core biopsies (n=152), fine-needle aspirations (n=130), or both (n=12); and 127 patients (43%) had subsequent surgical pathology follow-up. Most lesions (n=94; 74%) were mesenchymal on resection. These were initially diagnosed as negative (n=3; 2%), atypical (n=14; 11%), suspicious (n=5; 4%), malignant (n=35; 28%), and descriptive (n=70; 55%), with absolute risks of malignancy of 0%, 43%, 80%, 100%, and 44%, respectively. To align with the WHORSSTC, these cases were recategorized as insufficient/nondiagnostic (n=7; 6%), benign (n=13; 10%), atypical (n=12; 9%), soft tissue neoplasm of uncertain malignant potential (n=54; 43%), suspicious for malignancy (n=5; 4%), and malignant (n=36; 28%), with absolute risks of malignancy of 0%, 0%, 42%, 57%, 80%, and 100%, respectively. Although not all spindle cell lesions prove to be mesenchymal, they can be effectively categorized by the upcoming WHORSSTC with increasing risks of malignancy that better predict biologic potential.

Endobronchial ultrasound-guided transbronchial fine needle aspiration of mediastinal lymphadenopathy: Diagnostic performance and clinical implications of the World Health Organization reporting system.

Salivary gland neoplasm of uncertain malignant potential (SUMP) is an important diagnostic category of the Milan System for reporting salivary gland cytology (MSRSGC). Further subcategorization by cytomorphologic subtypes has been recommended to risk-stratify cases. In this study, our institutional experience with the risk of neoplasm (RON) and risk of malignancy (ROM) based on cytomorphologic subcategorization of SUMP is reported. We also report the prevalence of malignancy (POM) at our institution. The pathology database was queried for cases of fine-needle aspiration (FNA) diagnosed as SUMP along with follow-up at our institution from 2018-February 2024. This study was approved by an institutional review board. Of 1159 cases of salivary gland FNA specimens reported as per MSRSGC at our institution, 14.8% (171/1159 cases) were diagnosed as SUMP, with these reports verified by at least 16 cytopathologists. Surgical follow-up was available for 139/171 (81.3%) of these cases, for which the original cytomorphologic subgroups were as follows: 65 (46.8%) basaloid, 48 (34.5%) oncocytic/oncocytoid, 14 (10.1%) myoepithelial, 9 (6.5%) other, 2 (1.4%) clear cell, and 1 (0.7%) mucinous. The POM within SUMP at our institution is within a range of 29.8%-36.7%. When considering all cases, our institutional RON for SUMP was 97.8% (136/139), and the ROM was 36.7% (51/139). Notably, a significant portion of cases (36%, 50/139) underwent review at a daily intradepartmental consensus conference. Analysis revealed that SUMP cases that underwent consensus review had a ROM of 46% (23/50), versus 31.5% (28/89) in independently verified cases (p = .13). Of the cytomorphologic subgroups, basaloid SUMP in particular was more likely to be benign on resection when the case had been independently verified than after consensus review (p = .0082). When considering only the independently verified cases, the ROM for each subgroup was as follows: 38.7% (12/31) in oncocytic/oncocytoid, 20% (9/45) in basaloid, 33.3% (2/6) in myoepithelial, 60% (3/5) in "other", and 100% (1/1) in both mucinous and clear cell (p = .0407). While the RON is high across all cytomorphologic subgroups of SUMP, the ROM does vary across the groups, with basaloid cytomorphology having the lowest ROM. This effect is seen in independently verified cases but not in cases having undergone consensus review.

Risk of malignancy associated with the diagnostic categories proposed by the Papanicolaou Society of Cytopathology for pancreaticobiliary specimens: An institutional experience.