Reevaluation of ovarian cyst fine-needle aspiration cytology: A 10-year institutional experience.

OBJECTIVES: Fine-needle aspiration (FNA) of ovarian cyst fluid remains useful for certain clinical circumstances despite low sensitivity and potential safety concerns. The current study aimed to reevaluate the performance of ovarian cystic fluid cytology following American College of Obstetricians and Gynecologists guidelines using a single-institution cohort. METHODS: A total of 507 ovarian cyst FNA cases from 2013 to 2023 were reviewed. Patients' demographics and clinical and radiologic information were collected through the electronic database. The performance was calculated using corresponding surgical pathology diagnosis as the gold standard. RESULTS: Overall, cytologic diagnoses were nondiagnostic (ND), negative for malignancy (NFM), atypical (ATY), suspicious for malignancy (SFM), and malignant (M) in 5 (1.0%), 478 (94.3%), 14 (2.7%), 2 (0.4%), and 8 (1.6%) cases, respectively. Among 349 specimens (68.8%) that had a corresponding surgical pathology, the rate of malignancy (including borderline tumors) was 1.2% (4 of 325) in NFM, 72.7% in ATY (8 of 11), and 100% in both SFM (2 of 2) and M (8 of 8) specimens. Considering NFM and ATY as negative results and SFM and M as positive results, overall, the sensitivity of ovarian cystic fluid cytology was 45.4% and the specificity was 100%. CONCLUSIONS: As an uncommon test, ovarian cystic fluid cytology has moderate sensitivity and high specificity. Despite limitations, ovarian cystic FNA cytology remains a valuable diagnostic tool in certain aspects.

Sarcomatoid and Rhabdoid Renal Cell Carcinoma: Clinical, Pathologic, and Molecular Genetic Features.

Renal cell carcinoma (RCC) with sarcomatoid and rhabdoid morphologies has an aggressive biological behavior and a typically poor prognosis. The current 2022 WHO classification of renal tumors does not include them as distinct histologic entities but rather as transformational changes that may arise in a background of various distinct histologic types of RCC. The sarcomatoid component shows malignant spindle cells that may grow as intersecting fascicles, which is reminiscent of pleomorphic undifferentiated sarcoma. The rhabdoid cells are epithelioid cells with eccentrically located vesicular nuclei with prominent nucleoli and large intracytoplasmic eosinophilic inclusions. Studies have shown that RCCs with sarcomatoid and rhabdoid differentiation have distinctive molecular features. Sarcomatoid RCC harbors shared genomic alterations in carcinomatous and rhabdoid components, but also enrichment of specific genomic alterations in the sarcomatoid element, suggesting molecular pathways for development of sarcomatoid growth from a common clonal ancestor. Rhabdoid differentiation also arises through clonal evolution although less is known of specific genomic alterations in rhabdoid cells. Historically, treatment has lacked efficacy, although recently immunotherapy with PD-1/PD-L1/CTLA-4 inhibitors has produced significant clinical responses. Reporting of sarcomatoid and rhabdoid features in renal cell carcinoma is required by the College of American Pathologists and the International Collaboration on Cancer Reporting. This manuscript reviews the clinical, pathologic, and molecular features of sarcomatoid RCC and rhabdoid RCC with emphasis on the morphologic features of these tumors, significance of diagnostic recognition, the molecular mechanisms of tumorigenesis and differentiation along sarcomatoid and rhabdoid lines, and advances in treatment, particularly immunotherapy.

Cytologic evaluation of upper urinary tract specimens: An institutional retrospective study using The Paris System for Reporting Urine Cytology second edition with histopathologic follow-up.

OBJECTIVE: Cytologic evaluation of the upper urinary tract (UUT) can be challenging due to instrumentation artefacts. This study retrospectively reviewed UUT specimens using The Paris System for Reporting Urinary Cytopathology, second edition (TPS 2.0), compared it with the original reporting system (ORS) and correlated it with histopathologic follow-up. METHODS: An institutional database was reviewed for the UUT biopsy/resection histopathologic specimens, and we included 52 UUT cytology specimens pertinent to these cases in the study. These specimens were blindly reviewed and reclassified using TPS 2.0. The correlation between TPS 2.0, ORS and histopathologic follow-up was assessed. RESULTS: The UUT cytology specimens corresponded to 21 (40.4%) high-grade urothelial carcinoma (HGUC), 27 (51.9%) low-grade urothelial carcinoma (LGUC) and 4 (7.7%) benign cases on follow-up. For HGGC cases, the associated TPS categories included unsatisfactory (n = 1, 4.8%), negative for HGUC (NHGUC; n = 3, 14.3%), atypical urothelial cells (AUC; n = 6, 28.6%), suspicious for HGUC (SHGUC; n = 3, 14.3%) and HGUC (n = 8, 38.1%), while ORS categorised the specimens as unsatisfactory (n = 1, 4.8%), negative for malignant cells (NFMC; n = 3, 14.3%), AUC (n = 5, 23.8%), low-grade urothelial carcinoma (LGUC; n = 0, 0%), SHGUC (n = 5, 23.8%) and HGUC (n = 7, 33.3%). The risks of high-grade malignancy among cytologic categories were similar between ORS and TPS (p > 0.05). The majority of LGUC were classified as AUC similarly by ORS and TPS (55.6% vs. 59.3%). CONCLUSIONS: Our study demonstrated comparable performance between TPS 2.0 and ORS for UUT cytology specimens. Cytological diagnosis of UUT specimens remains challenging, especially for LGUC.

Utility of parathyroid hormone immunocytochemistry in fine needle aspiration diagnosis of parathyroid tissue.

OBJECTIVE: The cytomorphological features of parathyroid tissue (PTT) may overlap with those of thyroid lesions, thus posing a diagnostic challenge. In this retrospective study, we reviewed our institutional experience in using parathyroid hormone (PTH) immunocytochemistry (ICC) to substantiate the diagnosis of PTT on fine needle aspiration (FNA). METHODS: Our pathology database was searched for FNA cases in which PTH ICC was performed between 1 January 2015 and 31 March 2022. PTH ICC was performed on a ThinPrep slide in cases with a clinical suspicion of PTT or with cytomorphological features raising the possibility of PTT. Patients' clinicopathological characteristics, PTH ICC results, cytological diagnoses, and surgical follow-ups, if available, were reviewed and analysed. RESULTS: The study cohort included 103 cases clinically designated as thyroid (n = 85, 82.5%), parathyroid (n = 11, 10.7%) and neck soft tissue (n = 7, 6.8%). PTH immunostaining was negative, positive, and indeterminate in 53 (51.5%), 27 (26.2%), and 23 (22.3%) cases, respectively. Surgical follow-up was available in 27 (26.2%) cases, including 17 thyroid lesions and 10 PTT cases. All positive PTH cases were confirmed to be PTT, while all but one of the negative PTH cases were non-PTT on follow-up. The calculated sensitivity, specificity, positive and negative predictive values were 85.7%, 100%, 100% and 93.3%, respectively. CONCLUSION: Our study demonstrates that PTH ICC performed on additional ThinPrep slides is a valuable adjunct test in FNA samples with a differential diagnosis of PTT vs non-PTT. Low cellularity may be a limiting factor in the accurate assessment of PTH by ICC.

High-risk human papillomavirus testing in cytology aspiration samples from the head and neck part 1: a review of the literature on available testing options.

Human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma is increasing in incidence and is often first diagnosed on a cytology fine needle aspiration (FNA) specimen of metastatic nodal disease of the neck. In the setting of oropharyngeal squamous cell carcinoma, HPV status defines the disease with HPV-associated tumors having better overall prognosis than those that are HPV negative. Furthermore, metastatic squamous cell carcinoma of the neck of unknown origin requires testing for HPV as a positive result suggests an oropharyngeal primary. As a result, HPV testing in aspirate samples is increasingly important for the proper diagnosis and treatment of patients with head and neck squamous cell carcinoma. Although HPV testing in cervicovaginal cytology specimens is common and well-established, testing in head and neck FNA samples remains challenging. p16 immunohistochemistry is an excellent surrogate marker for HPV in tumors of known or suspected oropharyngeal origin, but the criteria used in histologic specimens may not be appropriate in cytology samples. FNA samples are more frequently hypocellular, and cytology cell blocks have variable fixation and processing steps, limiting the utility of p16 immunohistochemistry. Other potential testing options have been reported in the literature including staining of aspirate smears and molecular testing of liquid-based samples. The American Society of Cytopathology Clinical Practice Committee recently surveyed the American Society of Cytopathology membership to determine the current state of HPV testing in aspirate samples, and this review article is designed to provide a summary of the current literature on various testing options in FNA samples.

Copy number variations identified in thyroid FNA specimens are associated with Hürthle cell cytomorphology.

BACKGROUND: The fine-needle aspiration (FNA) diagnosis of thyroid Hürthle cell neoplasms (HCNs) remains challenging. This study explored a possible association of copy number variations (CNVs) with Hürthle cell lesions of the thyroid. METHODS: Thyroid FNA cases that were diagnosed as follicular lesion of undetermined significance (FLUS) or follicular neoplasm (FN)/HCN for which the ThyroSeq version 3 genomic classifier test was performed were retrieved. RESULTS: A total of 324 thyroid FNA cases (228 FLUS cases, 46 HCN cases, and 50 FN cases) were included in the study. FLUS cases were further classified as Hürthle cell type (follicular lesion of undetermined significance-Hürthle cell type [FLUS-HCT]; 20 cases) or non-Hürthle cell type (follicular lesion of undetermined significance-non-Hürthle cell type [FLUS-NHCT]; 208 cases). HCN and FLUS-HCT cases showed a higher prevalence of CNVs (23 of 66 [35%]) in comparison with those classified as FN or FLUS-NHCT (14 of 258 [5%]; P < .001). A total of 105 patients had histopathologic follow-up. Cases with CNVs were more likely to be neoplastic (18 of 26 [69%]) and associated with Hürthle cell changes (14 of 26 [54%]) in comparison with cases without any molecular alterations (neoplastic, 8 of 24 [33%]; Hürthle cell changes, 2 of 24 [8%]; P < .05). In HCN/FLUS-HCT cases with CNVs (n = 14), Hürthle cell changes (13 of 14 [93%]) and neoplasms (9 of 14 [64%]) were more likely to be seen on surgical follow-up in comparison with the 17 cases without CNVs (Hürthle cell changes, 6 of 17 [35%]; neoplastic, 3 of 17 [18%]; P < .05). CONCLUSIONS: CNVs identified in thyroid FNA cases are associated with Hürthle cell morphology and are suggestive of a neoplasm with Hürthle cell features in thyroid FNAs classified as FLUS-HCT/HCN. This finding may be helpful in triaging patients who would benefit from surgical management.

Clinicopathological Review of Micropapillary Urothelial Carcinoma.

PURPOSE OF REVIEW: This review will discuss micropapillary urothelial carcinoma with respect to biology, histopathologic characteristics, genetic and molecular features, diagnosis, clinical management, and future directions of research. RECENT FINDINGS: Recent consensus opinion study showed only moderate interobserver reproducibility in the diagnostic criteria. The most reproducible criteria with the highest consensus were multiple nests in the same lacunar spaces. There are recent reports of high rates of intratumoral heterogeneity of ERBB2 amplification within tumor containing both micropapillary and classic urothelial components. Micropapillary urothelial carcinoma is a well-documented highly aggressive variant of urothelial carcinoma with proven worse outcomes. Accurate recognition and reporting of this pattern is critical for optimal management. Newer therapeutic strategies related to the molecular and genetic findings seen in MPUC remain to be explored further.

RAS mutation and associated risk of malignancy in the thyroid gland: An FNA study with cytology-histology correlation.

BACKGROUND: Activating point mutations of the RAS gene (NRAS, HRAS, and KRAS) can be seen in benign and malignant thyroid tumors; among these, NRAS mutations are more commonly seen. This study was conducted to evaluate the thyroid risk of malignancy (ROM) associated with RAS mutations in thyroid fine-needle aspiration (FNA) at the authors' institution. METHODS: The authors searched their electronic database system between January 2015 and May 2021 for thyroid FNA cases with any type of RAS mutation. Molecular alterations were identified with the ThyroSeq Genomic Classifier, ThyGeNEXT (thyroid oncogene panel)/ThyraMIR (miRNA classifier), or ThyroSure gene panel. RESULTS: A total of 127 cases (age, 51 ± 14 years; 100 females and 27 males) were identified, and 72 had histologic follow-up. The overall ROM associated with RAS mutations (with or without any other molecular alterations) was 29%, whereas the ROM was lower (18%) with RAS mutations only. Isolated NRAS, HRAS, and KRAS mutation-associated ROMs were 15%, 27%, and 14%, respectively. Among these RAS-mutated cases, the cases with a Bethesda category IV cytologic diagnosis had a higher ROM than the cases with a category III diagnosis (38% vs 17%). Twenty-one histologically confirmed malignant cases were mostly classified on cytology as category IV lesions (14 of 34; 41%), and the remainder were either category III (6 of 35; 17%) or V lesions (1 of 1; 100%). CONCLUSIONS: This study demonstrated that the overall RAS mutation-associated ROM in thyroid FNA was intermediate (29%), and isolated HRAS mutations appeared to have a higher ROM (27%) than NRAS and KRAS mutations (15% and 14%, respectively).

Impact of Transoral Endoscopic Vestibular Approach Thyroidectomy on Pathologic Assessment.

CONTEXT.­: Since 2016, transoral endoscopic thyroid resection with vestibular approach (TOETVA) has been increasingly performed in the United States. Although guidelines for the procedure are evolving, indeterminate and malignant preoperative cytopathologic diagnoses are not a contraindication. There are limited data related to the pathologic examination of these specimens. OBJECTIVE.­: To examine the clinicopathologic features of TOETVA specimens with particular attention to limitations of interpretation of pathologic parameters and final diagnosis. DESIGN.­: We reviewed age, sex, preoperative imaging and cytologic diagnoses, surgical pathology, and clinical follow-up data in TOETVA resections from our institution for procedures performed between March 2016 and December 2019. RESULTS.­: Fifty cases of TOETVA were identified, comprising 48 women and 2 men with a mean age of 47 years. Preoperative cytologic diagnoses were available in 47 cases and included 19 nondiagnostic/benign (Bethesda I/II), 24 follicular lesion of undetermined significance/suspicious for follicular neoplasm (Bethesda III/IV), and 4 suspicious/malignant diagnoses (Bethesda V/VI). Thirty-four cases (68%) among the surgical resection specimens showed disruption and/or fragmentation. Thirty-nine cases were negative for carcinoma, including hyperplasias and benign/indolent neoplasms. Eleven cases exhibited papillary thyroid carcinoma. Final diagnoses were reached in all disrupted/fragmented cases. In 2 cases of papillary thyroid carcinoma, tumor size, microscopic extrathyroidal extension, and margin status could not be determined. CONCLUSIONS.­: A significant proportion of TOETVA specimens are disrupted/fragmented, which can compromise information about tumors, including size, number, margin status, and microscopic extrathyroidal extension. Given that these parameters inform treatment and follow-up, this should be considered when selecting patients for TOETVA.

Performing Calcitonin Immunocytochemistry on an Additional ThinPrep Slide in Fine-Needle Aspiration Diagnosis of Medullary Thyroid Carcinoma.

OBJECTIVES: This study reviewed the institutional experience of performing calcitonin immunostain on an additional ThinPrep slide in fine-needle aspiration (FNA) diagnosis of medullary thyroid carcinoma (MTC). METHODS: Thyroid FNA cases with MTC suspected or included in the differential diagnosis during cytologic evaluation and calcitonin immunostain performed were retrieved and reviewed. RESULTS: Calcitonin immunostain was performed in 132 cases with 41 positive, 81 negative, and 10 indeterminate results. All calcitonin-positive cases had a cytologic diagnosis of MTC while all calcitonin-negative cases were cytologically classified as non-MTCs except for two cases suspicious for MTC. In 10 cases with an indeterminate calcitonin result, diagnoses of non-MTC and suspicious for MTC were rendered in 6 and 4 cases, respectively. Histopathologic follow-up was available in 85 (64%) cases. All cytologically diagnosed MTC cases were confirmed on histopathology. In 3 MTC cases with an indeterminate calcitonin result, 1 case was misclassified cytologically as follicular neoplasm. The calculated sensitivity, specificity, positive predictive value, and negative predictive value of calcitonin immunostain were all 100% for diagnosing MTC. CONCLUSIONS: Our study demonstrates the feasibility of performing calcitonin immunostain on an additional ThinPrep slide. Calcitonin immunocytochemistry is a valuable adjunct test for FNA diagnosis and differential diagnosis of MTC.

Anaplastic Thyroid Carcinoma: Cytomorphologic Features on Fine-Needle Aspiration and Associated Diagnostic Challenges.

OBJECTIVES: Anaplastic thyroid carcinoma (ATC) is an aggressive malignancy, and early diagnosis, often aided by fine-needle aspiration (FNA), is key to improving patient prognosis. While the current literature describes some of the cytologic features (CFs) of this entity, a comprehensive examination of the CFs has not yet been performed. METHODS: We retrospectively searched our electronic database for ATC cases with available slides between January 2008 and December 2019. Cases were examined for 22 CFs and compared with a control group of differentiated thyroid carcinoma. RESULTS: A total of 18 ATC cases meeting our inclusion criteria were identified. Most cases showed moderate to high cellularity (83%) and epithelioid cytomorphology (83%). Architecture included either predominantly groups/clusters of tumor cells (56%) or single tumor cells (44%). The other CFs were as follows: nuclear enlargement (100%), nuclear crowding (89%), nuclear membrane irregularities (100%), multinucleated tumor cells (33%), and background acute inflammatory cells (50%). Of the CFs examined, statistically significant differences between ATC and the control groups were found in the following: nuclear pleomorphism, coarse/clumped chromatin, macronucleoli, apoptosis, and necrosis. CONCLUSIONS: Identification of key CFs in FNA coupled with the clinical history aids in the diagnosis of ATC and helps distinguish it from other mimickers.

Spatially resolved analysis of the T cell immune contexture in lung cancer-associated brain metastases.

Despite unique genetic alterations within brain metastases (BrMs) and an immunologically distinct surrounding microenvironment, the composition and functional properties of tumor-infiltrating lymphocytes within BrM remain largely unexplored. In particular, the expression of coinhibitory receptors, such as programmed cell death 1 (PD-1), T cell immunoglobulin mucin receptor 3 (TIM-3), and lymphocyte activation gene 3 (LAG-3), within BrMs is unknown. Using multiplexed quantitative immunofluorescence (QIF), this study evaluates the localized expression of PD-L1, level and functional profile of major T cell subsets, and coinhibitory receptors within lung cancer-associated BrMs and primary lung tumors. Clinicopathologically annotated samples from 95 patients with lung cancer between 2002 and 2015 were represented in a tissue microarray format. Spatially resolved and multiplexed QIF was used to evaluate PD-L1 protein, phenotype markers for major T cell subsets (CD3, CD4, CD8, and FOXP3), cell-localized activation and proliferation markers (granzyme B and Ki67), and coinhibitory receptors (PD-1, LAG-3, and TIM-3). The signal for each marker was measured in marker-selected tissue compartments, and associations between marker levels, tumor location, and major clinicopathological variables were studied. In total, 41 primary lung tumors and 65 BrMs were analyzed, including paired samples from 11 patients. Levels of tumor PD-L1 expression were comparable between BrMs and primary lung tumors. BrMs had significantly lower levels of all T cell subsets relative to primary lung tumors, and T cells in BrMs displayed lower levels of granzyme B than primary lesions. PD-1, TIM-3, and LAG-3 levels in CD3+ T-cells were also significantly lower in BrMs. Marker expression in patients with paired samples from BrMs and primary lung tumors showed comparable results. High CD3+ T-cells, as well as high levels of TIM-3 and LAG-3 in CD3+ T-cells, were associated with longer overall survival in BrMs but not primary lung tumors. Lung cancer-associated BrMs display lower T cell infiltration, markers of cytolytic function, and immune regulatory signals than primary lung tumors. Despite these differences, high TIM-3 and high LAG-3 expressions in CD3+ T-cells were associated with longer survival. These features are accompanied by comparable levels of PD-L1 protein expression compared with primary lung tumors. These results highlight unique aspects of the tumor immune microenvironment within the brain and provide further support for intracranially focused therapies.

Adverse Histopathologic Characteristics in Small Papillary Renal Cell Carcinomas Have Minimal Impact on Prognosis.

OBJECTIVES: Tumor size has long been used in the management decision-making of patients with renal masses. Active surveillance had recently gained traction in selected patients with tumor size of 4 cm or less. Adverse histopathologic characteristics in papillary renal cell carcinoma (PRCC) have been shown to correlate with worse prognosis. We aimed to study whether such features in small PRCCs provide additional prognostic information. METHODS: Nephrectomies from our institution were collected and reviewed to evaluate for adverse histopathologic features. Clinical follow-up information was collected for all cases. Relationships between the variables were examined by Wilcoxon test and logistic regression. RESULTS: We identified 291 consecutive cases of PRCC. Adverse tumor histopathologic characteristics were significantly related to size. In PRCCs with size greater than 4 cm, there were more cases with high World Health Organization/International Society of Urological Pathology grade and necrosis. Adverse histologic features are less commonly seen in small PRCC and are not associated with lower disease-free survival or disease-specific survival. CONCLUSIONS: Identification of these features in small PRCCs (≤4 cm) through needle core biopsy examination would not provide additional prognostic information in patients for whom active surveillance is considered. Clinical and radiologic follow-up in patients with small renal masses that have a known histologic diagnosis of PRCC should be sufficient.

Expression of insulinoma-associated protein 1 in non-small cell lung cancers: a diagnostic pitfall for neuroendocrine tumors.

Insulinoma-associated protein 1 (INSM1) has been reported as a highly sensitive and specific marker of neuroendocrine tumors. INSM1 expression has also been reported, although uncommonly, in non-neuroendocrine tumors. This study aimed to elucidate potential nonspecific INSM1 expression in non-small cell non-neuroendocrine lung cancers (NSCNELCs), especially in squamous cell carcinomas (SqCCs) with basaloid features to avoid diagnostic pitfalls. Tissue microarrays (TMAs) were constructed for 324 NSCNELCs, including 196 adenocarcinomas (AdCs), 86 SqCCs, and 42 other NSCNELCs. In addition, 38 whole-tissue sections of SqCCs with basaloid features were examined. INSM1 immunostain was semiquantitively evaluated based on the percentage of nuclear staining in tumor cells, categorized as negative, focal (<10% tumor cells), and positive (>10% tumor cells). Among 324 TMAs, 6.2% (20/324) were positive for INSM1, 4.9% (16/324) were focal, and 88.9% (289/34) were negative. Of 196 AdCs, 5.1% (10/196) were positive for INSM1, 4.7% (9/196) were focal, and 90.3% (177/196) were negative. Of 86 SqCCs, 9.3% (8/86) were positive for INSM1, 5.8% (5/86) were focal, and 84.9% (73/86) were negative. Of the remaining 42 NSCNELCs, 4.8% (2/42) were positive for INSM1, 4.8% (2/42) were focal, and 90.4% (38/44) were negative. Among 38 cases of whole-tissue sections of SqCCs with basaloid features, 15.8% (6/38) were positive for INSM1, 18.4% (7/38) were focal, and 65.8% (25/38) were negative. Our study demonstrates that INSM1 is expressed in a significant subset of NSCNELCs, suggesting caution in interpreting INSM1 staining, especially with limited samples. INSM1 should not be used as a stand-alone neuroendocrine marker in differentiating primary lung tumors.

New developments in existing WHO entities and evolving molecular concepts: The Genitourinary Pathology Society (GUPS) update on renal neoplasia.

The Genitourinary Pathology Society (GUPS) reviewed recent advances in renal neoplasia, particularly post-2016 World Health Organization (WHO) classification, to provide an update on existing entities, including diagnostic criteria, molecular correlates, and updated nomenclature. Key prognostic features for clear cell renal cell carcinoma (RCC) remain WHO/ISUP grade, AJCC/pTNM stage, coagulative necrosis, and rhabdoid and sarcomatoid differentiation. Accrual of subclonal genetic alterations in clear cell RCC including SETD2, PBRM1, BAP1, loss of chromosome 14q and 9p are associated with variable prognosis, patterns of metastasis, and vulnerability to therapies. Recent National Comprehensive Cancer Network (NCCN) guidelines increasingly adopt immunotherapeutic agents in advanced RCC, including RCC with rhabdoid and sarcomatoid changes. Papillary RCC subtyping is no longer recommended, as WHO/ISUP grade and tumor architecture better predict outcome. New papillary RCC variants/patterns include biphasic, solid, Warthin-like, and papillary renal neoplasm with reverse polarity. For tumors with 'borderline' features between oncocytoma and chromophobe RCC, a term "oncocytic renal neoplasm of low malignant potential, not further classified" is proposed. Clear cell papillary RCC may warrant reclassification as a tumor of low malignant potential. Tubulocystic RCC should only be diagnosed when morphologically pure. MiTF family translocation RCCs exhibit varied morphologic patterns and fusion partners. TFEB-amplified RCC occurs in older patients and is associated with more aggressive behavior. Acquired cystic disease (ACD) RCC-like cysts are likely precursors of ACD-RCC. The diagnosis of renal medullary carcinoma requires a negative SMARCB1 (INI-1) expression and sickle cell trait/disease. Mucinous tubular and spindle cell carcinoma (MTSCC) can be distinguished from papillary RCC with overlapping morphology by losses of chromosomes 1, 4, 6, 8, 9, 13, 14, 15, and 22. MTSCC with adverse histologic features shows frequent CDKN2A/2B (9p) deletions. BRAF mutations unify the metanephric family of tumors. The term "fumarate hydratase deficient RCC" ("FH-deficient RCC") is preferred over "hereditary leiomyomatosis and RCC syndrome-associated RCC". A low threshold for FH, 2SC, and SDHB immunohistochemistry is recommended in difficult to classify RCCs, particularly those with eosinophilic morphology, occurring in younger patients. Current evidence does not support existence of a unique tumor subtype occurring after chemotherapy/radiation in early childhood.

High-Risk Human Papillomavirus Testing, Genotyping, and Histopathologic Follow-up in Women With Abnormal Glandular Cells on Papanicolaou Tests.

OBJECTIVES: This study examined the association of high-risk human papillomavirus (hrHPV) status and HPV genotype with histopathologic follow-ups in women with an atypical glandular cell (AGC) interpretation. METHODS: Cases with AGC interpretation on a Papanicolaou (Pap) test were retrieved along with hrHPV testing, genotyping, and histologic follow-up results if available. RESULTS: A total of 561 AGC cases were identified, with histologic follow-up available for 471 cases (84%). The follow-up diagnoses included benign or reactive changes (60% of cases), low-grade cervical intraepithelial neoplasia (18%), high-grade cervical intraepithelial neoplasia (CIN2-3; 7%), cervical carcinoma (5%), and other malignancies (10%). Tests for hrHPV were positive in 128 of 426 (30%) cases, including HPV16 (30%), HPV18 (14%) and other HPV subtypes (56%). A positive hrHPV result significantly increased the risk of developing CIN2-3 or cervical carcinoma (odds ratio, 24.6; 95% CI, 9.9-58.9) and HPV16 or HPV18 further increased the risk (odds ratio, 49.5; 95% CI, 17.7-123.7). CONCLUSIONS: Our data demonstrate that in women with an AGC Pap interpretation, a positive hrHPV result, especially type 16 or 18, is associated with an increased risk of developing cervical CIN2-3 or higher lesions, suggesting potential implications of hrHPV testing for the management of patients with an AGC result on a Pap test.

Fine-Needle Aspiration Biopsy of Intraocular Mass-Like Lesions.

OBJECTIVES: The purpose of this study was to evaluate the diagnostic performance of fine-needle aspiration (FNA) biopsy for intraocular mass-like lesions and its contributing factors. METHODS: Intraocular FNA cases were retrieved and reviewed along with histopathologic follow-ups, if available. The effects of rapid on-site evaluation (ROSE), repeated biopsy, and adjunct immunocytochemical studies on cytologic diagnoses were analyzed. RESULTS: Of 72 FNA biopsies from 63 patients, nondiagnostic biopsy was seen in 17 cases (24%), whereas a definitive diagnosis was rendered in 39 cases (54%). The cytologic diagnoses correlated well with histopathologic follow-ups with a concordance rate of 61%. Almost all nondiagnostic biopsies (16/17, 94%) were seen in cases in which ROSE was not performed. Of the 7 patients in whom biopsy was repeated, a definitive diagnosis was rendered in 4 cases (57%). Immunocytochemistry was performed in the majority of cases with a malignant diagnosis, especially in metastatic tumors (75%). CONCLUSIONS: Our data demonstrates that FNA is an effective tool for the diagnosis of intraocular tumors. ROSE, repeated biopsy, and adjunct immunocytochemistry can help reduce the nondiagnostic rate and/or enhance diagnosis of malignancy, further improving FNA diagnostic performance.

Novel, emerging and provisional renal entities: The Genitourinary Pathology Society (GUPS) update on renal neoplasia.

The Genitourinary Pathology Society (GUPS) undertook a critical review of the recent advances in renal neoplasia, particularly focusing on the newly accumulated evidence post-2016 World Health Organization (WHO) classification. In the era of evolving histo-molecular classification of renal neoplasia, morphology is still key. However, entities (or groups of entities) are increasingly characterized by specific molecular features, often associated either with recognizable, specific morphologies or constellations of morphologies and corresponding immunohistochemical profiles. The correct diagnosis has clinical implications leading to better prognosis, potential clinical management with targeted therapies, may identify hereditary or syndromic associations, which may necessitate appropriate genetic testing. We hope that this undertaking will further facilitate the identification of these entities in practice. We also hope that this update will bring more clarity regarding the evolving classification of renal neoplasia and will further reduce the category of "unclassifiable renal carcinomas/tumors". We propose three categories of novel entities: (1) "Novel entity", validated by multiple independent studies; (2) "Emerging entity", good compelling data available from at least two or more independent studies, but additional validation is needed; and (3) "Provisional entity", limited data available from one or two studies, with more work required to validate them. For some entities initially described using different names, we propose new terminologies, to facilitate their recognition and to avoid further diagnostic dilemmas. Following these criteria, we propose as novel entities: eosinophilic solid and cystic renal cell carcinoma (ESC RCC), renal cell carcinoma with fibromyomatous stroma (RCC FMS) (formerly RCC with leiomyomatous or smooth muscle stroma), and anaplastic lymphoma kinase rearrangement-associated renal cell carcinoma (ALK-RCC). Emerging entities include: eosinophilic vacuolated tumor (EVT) and thyroid-like follicular renal cell carcinoma (TLFRCC). Finally, as provisional entities, we propose low-grade oncocytic tumor (LOT), atrophic kidney-like lesion (AKLL), and biphasic hyalinizing psammomatous renal cell carcinoma (BHP RCC).

Prognostic Assessment of BRAF Mutation in Preoperative Thyroid Fine-Needle Aspiration Specimens.

OBJECTIVES: We investigate the potential role of BRAF testing in guiding surgical intervention in papillary thyroid carcinoma (PTC). METHODS: Thyroid fine-needle aspiration (FNA) cases with available BRAF result and follow-up thyroidectomy for PTC were included in the study. Cytology and surgical diagnoses were correlated with BRAF status. RESULTS: There were 151 cases of thyroid FNA specimens with BRAF testing (70 mutant and 81 wild-type BRAF) and histologically confirmed unilateral, unifocal PTCs. There were no differences in age, sex, tumor size, or lymphovascular invasion on thyroidectomy specimens between mutant and wild-type BRAF cases. BRAF mutation was significantly associated with cytology diagnosis (P < .001), PTC subtype (P < .001), extrathyroidal extension (ETE) (P = .006), and higher tumor (T) stage (P = .04). However, an analysis within the histologic subtypes of PTC revealed no significant association between BRAF mutation and ETE or higher T stage. There was also no difference in central (P = .847) or lateral (p = 1) neck lymph node (LN) metastasis. CONCLUSIONS: BRAF mutation identified in thyroid FNA specimens correlates with histologic subtypes but is not an independent factor for predicting PTC biological behavior and should not be used to guide the extent of LN dissection.