Thyroid Fine-Needle Aspiration: The Current and Future Landscape of Cytopathology.

Thyroid cytology is a rapidly evolving field that has seen significant advances in recent years. Its main goal is to accurately diagnose thyroid nodules, differentiate between benign and malignant lesions, and risk stratify nodules when a definitive diagnosis is not possible. The current landscape of thyroid cytology includes the use of fine-needle aspiration for the diagnosis of thyroid nodules with the use of uniform, tiered reporting systems such as the Bethesda System for Reporting Thyroid Cytopathology. In recent years, molecular testing has emerged as a reliable preoperative diagnostic tool that stratifies patients into different risk categories (low, intermediate, or high) with varying probabilities of malignancy and helps guide patient treatment.

Artificial Intelligence Applications in Cytopathology: Current State of the Art.

The practice of cytopathology has been significantly refined in recent years, largely through the creation of consensus rule sets for the diagnosis of particular specimens (Bethesda, Milan, Paris, and so forth). In general, these diagnostic systems have focused on reducing intraobserver variance, removing nebulous/redundant categories, reducing the use of "atypical" diagnoses, and promoting the use of quantitative scoring systems while providing a uniform language to communicate these results. Computational pathology is a natural offshoot of this process in that it promises 100% reproducible diagnoses rendered by quantitative processes that are free from many of the biases of human practitioners.

Utility of the Milan System for Reporting Salivary Gland Cytopathology in fine needle aspiration cytology of minor salivary gland lesions.

INTRODUCTION: Salivary gland lesions are routinely evaluated by fine-needle aspiration cytology (FNAC) preoperatively. The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) has standardized salivary gland FNAC reporting. Its application in major salivary glands (MSGs) has been well-established; however, its utility in minor salivary glands (MiSGs) is not well-known. We studied the utility of MSRSGC in MiSG FNAC. MATERIALS AND METHODS: A retrospective search of MiSG FNACs from 2 academic institutions (2006-2023) was performed. FNACs were classified using the MSRSGC. Histologic data were reviewed and recorded. The risk of malignancy (ROM), risk of neoplasia (RON), diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. RESULTS: The series included 43 MiSG FNAC (24 males and 18 females), with a mean age of 55 years (range 10-92). Aspirated sites included the following: palate, buccal space, floor of mouth, lip, tongue, and maxillary sinus. FNACs were classified as nondiagnostic (1), nonneoplastic (3), atypia of undetermined significance (6), benign neoplasm (9), salivary gland neoplasm of uncertain malignant potential (15), suspicious for malignancy, (2) and malignant (7). The risk of neoplasia and risk of malignancy were 87% and 39%. The diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 100%, respectively. CONCLUSIONS: Milan System for Reporting Salivary Gland Cytopathology offers valuable information for stratifying MiSG lesions. However, the distribution and the range of diagnostic entities encountered differ somewhat from those in MSGs. For instance, mucinous cyst contents may warrant unique consideration in MiSG; while an atypical classification is recommended in MSGs, the high prevalence of mucoceles in MiSG may tilt this group toward benignity.

Cytologic features of differentiated high-grade thyroid carcinoma: A multi-institutional study of 40 cases.

BACKGROUND: Differentiated high-grade thyroid carcinoma (DHGTC) is recently recognized by the World Health Organization (WHO) as a subgroup of thyroid carcinomas with high-grade features while retaining the architectural and/or cytologic features of well-differentiated follicular-cell-derived tumors. The cytomorphology of DHGTC is not well documented despite potential implications for patient triage and management. METHODS: The pathology archives of six institutions were searched for cases diagnosed on resection as "high-grade thyroid carcinoma" using WHO criteria. The fine-needle aspiration (FNA) cohort represents a 10-year period (2013-2023); all were reviewed to confirm DHGTC classification. The corresponding FNAs were assessed for 32 cytomorphologic features. RESULTS: Forty cases of DHGTC with prior FNA were identified. The mean patient age was 64.2 years. The average lesion size was 4.9 cm, and the majority demonstrated a TI-RADS score of 4 or 5 (95.2%). Three main high-grade subsets of DHGTC based on corresponding histology included papillary thyroid carcinoma (65%), follicular carcinoma (22.5%), and oncocytic carcinoma (12.5%). Over 97% of FNA cases were classified as Bethesda category IV or above. Approximately 25% of DHGTC showed cytologic features that included marked cytologic atypia, increased anisonucleosis, large oval nuclei, mitotic activity, or necrosis (p < .05); 68% of DHGTC cases were associated with high-risk molecular alterations. TERT mutations occurred in 41%, of which 89% of these were associated with a second mutation, usually RAS or BRAF p.V600E. CONCLUSIONS: Cytology has a low sensitivity for DHGTC, although a subset of DHGTCs have cytologic features raising the possibility of a high-grade thyroid carcinoma. Other findings include high-risk molecular changes and clinicopathologic features such as older patient age and larger lesion size.

Cementoblastoma Mimicking Pathology of Endodontic Origin: A Case Report.

Interdisciplinary care in the management of complex pathology is critical to ensure patients receive predictable, evidence-based treatment. The authors report the unique case of a healthy 38-year-old female patient who presented to a private endodontics practice with a radiopaque lesion associated with the root of tooth No. 20. The patient experienced mild and occasional palpation tenderness associated with the tooth. Extraoral examination and intraoral soft tissues presented without any abnormalities. Intraoral radiographs revealed a radiopacity overlying the apex of tooth No. 20. A cone-beam computed tomography scan of the region revealed a well-delineated bulbous radiopaque lesion attached to the lingual aspect of the apical third of the root of tooth No. 20. The lesion could not be distinguished from the root outline and presented with a radiolucent halo along its periphery. The differential diagnosis at the time consisted of cementoblastoma, condensing osteitis, hypercementosis, and periapical cemento-osseous dysplasia. The patient was referred to an oral and maxillofacial surgeon for evaluation and treatment. Tooth No. 20 was subsequently treated with an excisional biopsy and concurrent extraction of the tooth. Histologic examination of the lesion supported the diagnosis of cementoblastoma.

Atypical Spindle Cell/Pleomorphic Lipomatous Tumor With Sarcomatous Transformation: Clinicopathologic and Molecular Analysis of 4 Cases.

Atypical spindle cell/pleomorphic lipomatous tumor (ASPLT) is a recently described adipocytic tumor predominantly affecting the subcutaneous soft tissues of adults. Previous studies have shown that ASPLT follows a benign clinical course with a 4% to 12% local recurrence rate and no risk of dedifferentiation. Herein, we describe the clinicopathologic and molecular findings of 4 cases of ASPLT showing unequivocal sarcomatous transformation. Three patients were male and one was female, aged 65, 70, 74, and 78 years. Two cases presented as mass-forming lesions, while 1 case was incidentally discovered. The tumors measured 30, 55, 80, and 110 mm and occurred in the chest wall (n = 2) or arm (n = 2); all were subcutaneous. Microscopically, they showed a biphasic appearance comprising a low-grade ASPLT component and a high-grade sarcomatous component. The low-grade components showed features in the spectrum of either atypical pleomorphic lipomatous tumor (n = 2) or atypical spindle cell lipomatous tumor (n = 2). The high-grade components displayed leiomyosarcoma-like (n = 2), pleomorphic liposarcoma-like (n = 1) or undifferentiated sarcoma-like (n = 1) morphology. On immunohistochemistry, tumors were negative for MDM2 and showed loss of RB1 expression. In addition, the leiomyosarcoma-like areas seen in 2 cases were positive for smooth muscle actin and H-caldesmon. Single-nucleotide polymorphism array, performed in 3 cases, showed deletions of TP53, RB1, and flanking genes in both components. In contrast, the sarcomatous components showed more complex genomic profiles with rare segmental gains and recurrent loss of PTEN (n = 3), ATM (n = 2), and CDKN2A/B (n = 2) among other genes. Whole exome sequencing identified a TP53 variant in one case and an ATRX variant in another, each occurring in both tumor components. Limited clinical follow-up showed no recurrence or metastasis after 1 to 13 months (median, 7.5 months) postsurgical excision. Altogether, our data support that ASPLT can rarely develop sarcomatous transformation and offer insights into the molecular mechanisms underlying this event.

GLI1-Altered Mesenchymal Tumors.

GLI1-altered mesenchymal tumors comprise an emerging group of neoplasms characterized by fusions or amplifications involving GLI1, a gene that encodes a key regulator of the Hedgehog signaling pathway. In recent years, tumors with GLI1 alterations have been reported across a variety of anatomic sites and a broad age range. Although these tumors can exhibit a wide morphologic spectrum and a variable immunophenotype, they frequently present with monomorphic ovoid cells arranged in distinctive nests with a rich, arborizing vascular network. Recent evidence indicates that they have the potential to metastasize, which suggests that they may be best considered a sarcoma.

The art of specimen orientation: Two-dimensional maps for oropharynx squamous cell carcinoma.

The goal of surgical treatment for oropharynx squamous cell carcinoma (SCCa) is resection to negative margins. Current methods of orienting resection specimens often do not give a comprehensive view, especially in oropharynx SCCa where specimens can lack anatomic landmarks. We created standardized two-dimensional maps of oropharynx anatomy drawn to scale to improve communication between surgeons and pathologists. Notes regarding surgery including anatomic landmarks, areas of concern, additional margins, and relevant clinical information were added to the map. The maps guided pathology work-up, and the pathologist could communicate details back to the surgeon on how the specimen was sectioned or locations of microscopic foci to direct future treatment and clinical monitoring. The use of two-dimensional maps for oropharynx SCCa specimens offers a standardized solution to address the challenges of anatomic orientation. These maps summarized key pathological information, preserved clinical details from the specimens, and guided multidisciplinary conferences when planning adjuvant treatment.