Laura J. Tafe

Purpose: Pleomorphic adenoma (PA), the most common salivary neoplasm, is capable of tremendous histologic diversity. Co-occurrence of squamous and mucinous differentiation in PA is a rare phenomenon generally considered within its histologic spectrum, though previously advocated by some as evidence of mucoepidermoid carcinoma (MEC) ex PA. Herein, we describe a multi-institutional series of MEC-like PA with squamous differentiation, mucous cells, cystic change, and MALAT1::PLAG1 fusion. Materials and Methods: Retrospective multi-institutional review identified 5 PAs with MALAT1::PLAG1 fusion. Histopathologic and immunohistochemical slides were reviewed, as well as demographic, clinical, and molecular findings. Results: Five MALAT1::PLAG1 -rearranged PA occurred in the parotid gland of 3 female and 2 male patients (median age: 53 yrs, range: 47–58 yrs). Median tumor dimension was 2.5 cm (range: 1.4–3.4 cm). All tumors demonstrated characteristic histologic features of PA as well as areas of cystic squamous and mucinous differentiation resembling MEC (comprising 25–80% of the tumors). There was no capsular invasion or high-grade features. No canonical MEC driver alterations were identified by NGS. No recurrences were identified during available follow-up in 2 patients. Conclusion: Cystic squamous and mucinous differentiation may occur in PA, representing a potential diagnostic pitfall both in small biopsy specimens, where it can be misdiagnosed as MEC, as well as in resection specimens where it should not be interpreted as MEC ex PA. Instead, apparent association of these histologic features with MALAT1::PLAG1 fusion suggests a novel genotype–phenotype correlation in PA. Adjunct molecular testing may be valuable in diagnostically challenging cases.

Thousands of human remains lie unidentified in Medical Examiners' and Coroners' Offices across the United States of America. Determining identity is the first step in bringing closure to grieving families and communities and, in certain cases, moving towards justice. While many distance themselves from death, forensic specialists, including forensic photographers and artists, dive in, focusing intently on every detail to recapitulate the deceased's story. Forensic sketches serve a dual purpose—identification and remembrance. They have been used for over a century to help identify deceased bodies and connect them to their remaining loved ones. Common external characteristics are combined with accentuated distinguishing features to bring the body back to life in a recognizable form. Preserving human dignity, acting with respect and non‐maleficence, and contributing to justice are central in these postmortem proceedings. This comprehensive review explores the gravity of the silent mass disaster of unidentified human remains in the United States of America, the disparities that exist between the missing and the recovered and identified, and sheds light on the early introduction of artificial intelligence into the field of forensic identification.

Background: Malignant serous effusions (MSEs), including pleural, pericardial, and peritoneal effusions, are common in advanced lung adenocarcinoma (LUAD). However, integrated clinicopathologic, molecular, treatment, and outcome data across effusion sites remain incompletely defined. Methods: This study retrospectively analyzed 120 cytology‐confirmed LUAD‐associated MSE cases from a single academic center by integrating gross fluid features, cytopathology, immunohistochemistry, targeted next‐generation sequencing (NGS), systemic therapy, and clinical outcomes, including survival from first malignant effusion (SME) and overall survival (OS). Results: Effusions were pleural (85 of 120; 70.8%), pericardial (28 of 120; 23.3%), and peritoneal (7 of 120; 5.8%). Median SME was 3.8 months, and was shortest in the small peritoneal effusion subgroup (1.0 months). OS differed by site, with pericardial involvement showing the shortest OS (6.1 months). Thyroid transcription factor 1 (TTF‐1) was positive in 72.5% of cases. Programmed death ligand 1 (PD‐L1) testing ( n = 85) showed a tumor proportion score (TPS) of ≥1% in 80% of cases and TPS of ≥50% in 36.5% of cases. Molecular profiling was completed in 111 of 120 cases (92.5%) by identifying TP53 mutations in 47 of 111 (42.3%) and actionable driver alterations in 42.3% of cases, most commonly involving EGFR , KRAS , BRAF , ALK , and ROS1 . TTF‐1 positivity was associated with higher rates of actionable driver alterations and higher PD‐L1 expression. PD‐L1 negativity, TTF‐1 negativity, and an absence of actionable driver alterations were associated with shorter SME and OS. Dual TTF‐1/PD‐L1 negativity defined the poorest risk subgroup (median SME, 1.2 months; median OS, 1.4 months). Multivariable analysis confirmed that TTF‐1 negativity and a lack of actionable drivers remained independently adverse. Among treated patients, immunotherapy‐based regimens were associated with the longest SME (6.7 months), whereas tyrosine kinase inhibitor–based therapy was associated with the longest OS (26.0 months). Conclusions: Integration of cytology, immunophenotype, genomics, and treatment delineates distinct prognostic subsets in LUAD with MSE. The absence of actionable driver alterations and TTF‐1 negativity remains an independent adverse prognostic factor, with dual TTF‐1/PD‐L1‐negative MSE showing particularly poor SME and OS.

Background: Optical genome mapping (OGM) detects genome-wide structural variants (SVs), including balanced rearrangements and complex copy-number alterations beyond standard-of-care cytogenomic assays. In chronic lymphocytic leukemia (CLL), cytogenetic and genomic risk stratification is traditionally based on fluorescence in situ hybridization (FISH), karyotyping, targeted next-generation sequencing (NGS), and immunogenetic assessment of immunoglobulin heavy chain variable region (IGHV) somatic hypermutation status, each of which interrogates only a limited aspect of disease biology. Methods: We retrospectively evaluated fifty patients with CLL using OGM and integrated these findings with cytogenomics, targeted NGS, IGHV mutational status, and clinical time-to-first-treatment (TTFT) data. Structural variants were detected using OGM and pathogenic NGS variants were derived from a clinical heme malignancy panel. Clinical outcomes were extracted from the electronic medical record. Results: OGM identified reportable structural variants in 82% (41/50) of cases. The most frequent abnormality was del(13q), observed in 29/50 (58%) and comprising 73% (29/40) of all OGM-detected deletions with pathologic significance. Among these, 12/29 (42%) represented large RB1-spanning deletions, while 17/29 (58%) were focal deletions restricted to the miR15a/miR16-1 minimal region, mapping to the non-coding host gene DLEU2. Co-occurrence of adverse lesions, including deletion 11q/ATM, BIRC3 loss, trisomy 12, and deletion 17p/TP53, were recurrent and strongly associated with shorter TTFT. OGM also uncovered multiple cryptic rearrangements involving chromosomal loci that are not represented in the canonical CLL FISH probe panel, including IGL::CCND1, IGH::BCL2, IGH::BCL11A, IGH::BCL3, and multi-chromosomal copy-number complexity. IGHV data were available in 37/50 (74%) of patients; IGHV-unmutated status frequently co-segregated with OGM-defined high-risk profiles (del(11q), del(17p), trisomy 12 with secondary hits, and complex genomes whereas mutated IGHV predominated in OGM-negative or structurally simple del(13q) cases and aligned with indolent TTFT. Integration of OGM with NGS further improved genomic risk classification, particularly in cases with discordant or inconclusive routine testing. Conclusions: OGM provides a comprehensive, genome-wide view of structural variation in CLL, resolving deletion architecture, identifying cryptic translocations, and defining complex multi-hit genomic profiles that tracked closely with clinical behavior. Combining OGM and NGS analysis refined risk stratification beyond standard FISH panels and supports more precise, individualized management strategies in CLL. Prospective studies are warranted to evaluate the clinical utility of OGM-guided genomic profiling in contemporary treatment paradigms.

PURPOSE: Chromosomal rearrangements drive tumorigenesis through fusion transcripts. Clinical whole-transcriptome sequencing (WTS) enables comprehensive fusion detection, overcoming limitations of targeted methods, but its clinical application has been hindered by technical and cost barriers. METHODS: We validated a clinical bait-capture WTS assay using 78 solid tumor samples across diverse tissue types, including 59 with known fusions or oncogenic splice variants. Sensitivity was assessed against clinically reported fusions from targeted next-generation sequencing or fluorescence in situ hybridization. Analytical performance was evaluated for sensitivity, specificity, limit of detection, and reproducibility across varying RNA inputs and sequencing conditions. Clinical implementation data were also analyzed. RESULTS: WTS demonstrated a sensitivity of 97.1% and a specificity of 100% for detecting clinically relevant fusions. Detection was robust across tumor types, with RNA input as low as 1 ng. Optimized sequencing thresholds of 60 million reads and 130-bp read length improved performance. The assay was highly reproducible and resistant to common contaminants. Over 6 months of clinical use (410 specimens), WTS identified 29 fusions (7% detection rate), including six clinically relevant fusions undetectable by our institution's previous targeted panel, increasing the fusion yield by 26%. CONCLUSION: WTS provides high sensitivity, specificity, and expanded fusion detection, supporting its routine clinical adoption. Future work will explore its broader role in integrated genomic profiling and therapeutic guidance.

Background: Cytological evaluation is essential for assessing pericardial effusions (PEs) in non–small cell lung cancer (NSCLC). This study retrospectively examined the clinicopathological, molecular, and prognostic characteristics of patients with NSCLC with PE.Methods: Clinical data from 80 patients with NSCLC with PE treated at an academic center over the course of 15 years were reviewed. PE specimens were categorized according to the International System for Reporting Serous Fluid Cytopathology (ISRSFC). The analysis included patient demographics, molecular alterations, cytopathology, histology, and survival outcomes.Results: Of the 80 patients, 36 (45%) were female and 90% had stage IV disease. A smoking history was noted in 58 patients (72.5%), and 22 patients (27.5%) presented with tamponade. Lung adenocarcinoma predominated (87.5%). The ISRSFC categorized 25% of the specimens as negative for malignancy (NFM), 7.5% as atypia of undetermined significance (AUS), 3.75% as suspicious for malignancy (SFM), and 63.75% as malignant (MAL). Immunohistochemistry in 57 specimens identified thyroid transcription factor 1 (65%) as the most frequently positive marker. Molecular analysis revealed p53 mutations (59.1%) as the most prevalent, followed by KRAS (34.1%) and EGFR (15.9%). Kaplan–Meier analysis showed significantly better survival for NFM patients than non‐NFM patients (MAL, SFM, and AUS; p = .0036). Bloody PEs and tamponade were associated with worse outcomes. The immunotherapy group achieved the most prolonged survival among stage IV patients (9.07 months; p = .017). Cox regression confirmed cytology‐negative status as an independent prognostic factor.Conclusions: Cytological evaluation and ISRSFC classification are crucial for NSCLC‐associated PEs. A multidisciplinary approach integrating cytology, immunohistochemistry, and molecular profiling is essential for optimal management and prognosis.

Approximately 30% of endometrial cancers are associated with microsatellite instability (MSI) caused by deficiencies in the DNA mismatch repair (MMR) genes (dMMR). MMR testing by immunohistochemistry for MMR proteins and MSI testing by polymerase chain reaction (PCR) are routinely utilized to screen patients with colorectal cancer and endometrial cancer for Lynch syndrome and, more recently, to identify patients eligible for immunotherapy. The Biocartis Idylla™ MSI assay is a fully automated, cartridge-based real-time PCR assay. The assay uses as little as one formalin-fixed paraffin-embedded (FFPE) tumor section and is designed to detect seven novel MSI biomarkers consisting of short homopolymers located in ACVR2A , BTBD7 , DIDO1 , MRE11 , RYR3 , SEC31A and SULF2 genes. Mutation in two of these markers is considered MSI-H. FFPE of 35 ECs (25 dMMR and 10 microsatellite stable (MSS)) were used in this study. When tumor content was ≤20% on a slide, macrodissection was performed. The overall percent agreement with MMR IHC was 97% (31/32) with sensitivity = 96% and specificity = 100%. Pre-analytic evaluation of the manufacturer's recommended 20% tumor content cut-off is essential to ensure valid results. The Idylla MSI assay offers several advantages over other PCR-based assays including minimal hands-on time, rapid turn-around-time, no requirement for a paired normal sample and the use of FFPE directly without an extraction step.

Purpose Mesenchymal neoplasms composed of vascular, smooth muscle, and adipocytic components are uncommon in the nasal cavity. While angioleiomyoma (AL) is a smooth muscle tumor in the Head & Neck WHO classification, it is considered of pericytic origin in the Skin as well as Soft Tissue and Bone classifications. For nasal AL with an adipocytic component, the terms AL with adipocytic differentiation and angiomyolipoma (AML) have been applied, among others. AML is a type of perivascular epithelioid cell tumor (PEComa), most often arising in the kidney, sometimes associated with the tuberous sclerosis complex (TSC). It is uncertain whether nasal cavity AML and AL are best considered hamartomas or neoplasms, as their genetics are largely unexplored. Methods We performed a multi-institutional retrospective study of nasal cavity mesenchymal lesions. Patient demographics, clinical histories, and histologic and immunohistochemical findings were collected. DNA and RNA were extracted from formalin-fixed, paraffin-embedded tissue and analyzed by SNP-based chromosomal microarray, targeted RNA fusion sequencing, and whole-exome sequencing. Results Fifteen lesions (3–42 mm) were identified, predominantly in male (87%) patients with a median age of 60. Patients typically presented with obstructive symptoms, and none had a history of TSC. One AL was a recurrence from six years prior; 11 cases showed no recurrence (median 4.7 years, range: 0.88–12.4). Morphologically, 11 AML contained 30–80% smooth muscle, 10–25% vasculature, and 2–60% adipose tissue, while four AL contained 70–80% smooth muscle and 20–30% vasculature. Other histologic observations included ulceration, thrombosis, inflammation, myxoid change, senescent nuclei, and extramedullary hematopoiesis; no well-developed epithelioid cell morphology was identified. Immunohistochemically, all cases were positive for smooth muscle markers (actin, desmin, and/or caldesmon) and negative for melanocytic markers. Molecular analysis revealed loss of 3p and 11q in a single AML. No other known pathogenic copy number or molecular alterations were seen, including in TSC1/2, TFE3, or NOTCH2. Conclusion Nasal cavity AML lacks morphologic, immunophenotypic, and genetic features of PEComa family AML. The significant histologic overlap between nasal AML and AL without distinguishing molecular features in either entity suggests “sinonasal angioleiomyoma with adipocytic differentiation” may be the most appropriate terminology for hybrid vascular and smooth muscle lesions containing adipocytic components.