Head and neck pathology最新文献

{"title":"DNA Methylation Signatures of Upper Aerodigestive Tract Squamous Cell Carcinoma and Sarcomatoid Squamous Cell Carcinoma Are Similar: A Potential Novel Diagnostic Tool for the Diagnosis of Sarcomatoid Squamous Cell Carcinoma.","authors":"Josephine K Dermawan, Christopher C Griffith, Jennifer Starbuck, Sheila Shurtleff, Travis Hattery, Joy Nakitandwe, Shauna Campbell, John S A Chrisinger, Mark J Chen, Elizabeth M Azzato, Karen J Fritchie","doi":"10.1007/s12105-026-01958-4","DOIUrl":"10.1007/s12105-026-01958-4","url":null,"abstract":"<p><strong>Purpose: </strong>Upper aerodigestive tract squamous cell carcinoma (UATSCC) is often easy to recognize in its conventional form. However, a subset of tumors loses histologic evidence of squamous differentiation and, instead, become sarcomatoid (spindled). These cases may be difficult or impossible to appropriately classify on biopsy material, even with immunohistochemistry. DNA methylation has emerged as a tool to help in classifying undifferentiated malignancies. We sought to explore whether conventional and sarcomatoid UATSCC harbor the same epigenetic signature.</p><p><strong>Methods: </strong>Cases of sarcomatoid UATSCC were collected and reviewed. The conventional and sarcomatoid components were documented. Only specimens with concomitant epithelial dysplasia and/or invasive SCC were included. A panel of keratins (CK AE1/3, CAM5.2 and CK5/6) was performed on the sarcomatoid component of each tumor and scored as follows: 0, < 1%; 1+, 1-25%; 2+, 26-50%, 3+, > 50%. DNA methylation profiling was performed and compared with profiles from publicly available UATSCC and a control cohort of pleomorphic malignancies including undifferentiated sarcoma, leiomyosarcoma, angiosarcoma, atypical fibroxanthoma/pleomorphic dermal sarcoma, and melanoma, as well as sarcomatoid carcinoma of cutaneous origin.</p><p><strong>Results: </strong>21 UATSCC samples from 15 patients were retrieved (9 M, 6 F; 47-88 years, median 71 years) from sites including tongue (7), larynx (5), pharynx (3), maxillary/mandibular alveolar ridge (3), \"neck\" (2), and nasal cavity (1). 12 samples were entirely sarcomatous, while six were conventional SCC and three contained both sarcomatoid and conventional components. Of the sarcomatous components, six were entirely negative (score = 0) for all keratins performed. Using dimensionality reduction analysis of DNA methylation data by Uniform Manifold Approximation and Projection (UMAP) and unsupervised hierarchical clustering, 11 of 12 sarcomatoid UATSCC samples, were positioned with conventional UATSCC. Methylomes of sarcomatoid carcinoma of upper aerodigestive tract and cutaneous origin overlapped. Copy number profile analysis did not show significant differences between conventional and sarcomatoid histologies or tumor time point.</p><p><strong>Conclusion: </strong>The epigenetic signatures of conventional and sarcomatoid UATSCC are similar, even in cases that lack expression of multiple keratins. DNA methylation profiling may be leveraged in biopsies and entirely sarcomatoid UATSCC to accurately diagnose these cases and differentiate them from pleomorphic sarcomas and melanoma.</p>","PeriodicalId":520636,"journal":{"name":"Head and neck pathology","volume":"20 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13437858/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148674444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Early-Stage Oral Squamous Cell Carcinoma in Adolescents and Young Adults Compared with Older Patients Exhibits Distinct Clinicopathological Features.","authors":"Sawako Ono, Katsutoshi Hirose, Hotaka Kawai, Tatsuya Abe, Shintaro Sukegawa, Masanori Masui, Chihoko Ikeda, Madoka Isomura, Yuri Tachibana, Junya Ono, Katsumitsu Shimada, Hitoshi Nagatsuka, Hidetaka Yamamoto","doi":"10.1007/s12105-026-01944-w","DOIUrl":"10.1007/s12105-026-01944-w","url":null,"abstract":"<p><strong>Purpose: </strong>This study aimed to compare the clinicopathological features of stage I-II oral squamous cell carcinoma (OSCC) between adolescents and young adults (AYAs) and older patients, and to identify prognostic factors in AYA OSCC.</p><p><strong>Methods: </strong>Forty-eight AYA patients aged 15-39 years and 69 older patients aged ≥ 65 years with surgically treated stage I-II OSCC were retrospectively analyzed. Histological evaluation, survival analysis, immunohistochemistry for p53, p16, and MTAP, high-risk HPV RNA in situ hybridization, and fluorescence in situ hybridization for CDKN2A and MTAP were performed.</p><p><strong>Results: </strong>Compared with older patients, OSCCs in AYAs were more frequently located on the tongue (93.7% vs. 47.8%) and more often exhibited a superficial spreading growth pattern (60.4% vs. 31.8%). AYA tumors more frequently showed modified WPOI-1, high tumor budding, and abnormal p53 immunophenotypes (85.4% vs. 68.1%). AYA patients showed significantly better overall and disease-free survival than older patients. Within the AYA group, depth of invasion (DOI) > 5 mm was associated with distant metastasis and poorer overall and disease-free survival. Postoperative lymph node metastasis occurred in 31.2% of AYAs. Univariable analysis suggested that clinical stage II, tumor thickness > 5 mm, DOI > 5 mm, and tumor budding scores 1-2 were associated with postoperative lymph node metastasis. Molecular status, including p53, p16/CDKN2A, and MTAP, did not provide robust prognostic stratification.</p><p><strong>Conclusion: </strong>Early-stage AYA OSCC exhibits distinct clinicopathological features. DOI was the strongest prognostic indicator, whereas clinical stage, tumor thickness, and tumor budding may provide additional prognostic information regarding the risk of late nodal metastasis.</p>","PeriodicalId":520636,"journal":{"name":"Head and neck pathology","volume":"20 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13427714/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148633601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pleomorphic Adenoma of the Palate with Bizarre Ductal and Myoepithelial Cells: A Case Image.","authors":"Katsutoshi Hirose, Masato Nakaguro, Kohei Kawamura, Taisuke Mori, Satoru Toyosawa","doi":"10.1007/s12105-026-01953-9","DOIUrl":"10.1007/s12105-026-01953-9","url":null,"abstract":"<p><strong>Background: </strong>Pleomorphic adenomas (PAs), the most common salivary gland tumors, are comprised of ductal epithelial and myoepithelial cells within a stromal background. A rare subset of PAs exhibits bizarre cells and 12q amplification involving HMGA2 and MDM2; in reported cases, bizarre cells have been confined to the myoepithelial component. We report the first case of a PA with bizarre-cytological features in both the ductal and myoepithelial components.</p><p><strong>Case presentation: </strong>A 75-year-old woman presented with a palatal mass. Histology revealed a well-circumscribed biphasic tumor with marked nuclear pleomorphism in both luminal ductal and non-luminal myoepithelial cells. Despite the alarming atypia, mitotic activity was low, and neither necrosis nor invasive growth was observed. Immunohistochemically, luminal bizarre cells exhibited ductal characteristics, whereas non-luminal bizarre cells exhibited myoepithelial characteristics. Tumor cells were negative for androgen receptor and HER2 and showed a p53 wild-type expression pattern. The Ki-67 labeling index was < 5%, and the bizarre cells rarely tested positive. Molecular analysis demonstrated amplification of HMGA2 and MDM2, whereas no other pathogenic variants related to salivary gland tumors were detected. Complete excision was performed; no evidence of recurrence or metastasis was observed after 10 months.</p><p><strong>Conclusion: </strong>Marked cytological atypia of bizarre cells in PA, even when involving ductal cells, may not necessarily indicate malignancy. This case highlights the value of integrating clinicopathological and genetic findings to better define PAs with bizarre cells and prevent overdiagnosis of carcinoma based on atypia alone.</p>","PeriodicalId":520636,"journal":{"name":"Head and neck pathology","volume":"20 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13407779/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148595368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lenalidomide-Associated Oral Pigmentation: A Case Report.","authors":"André Luis Santana de Freitas, Fabiana Gomes Cardoso Pereira de Sousa, Cleverson Teixeira Soares, Rosane Rezende de Souza Giuliani, Andresa Borges Soares","doi":"10.1007/s12105-026-01954-8","DOIUrl":"10.1007/s12105-026-01954-8","url":null,"abstract":"<p><strong>Background: </strong>Lenalidomide is an immunomodulatory agent widely used in the treatment of multiple myeloma and is generally associated with a favorable safety profile. Although pigmentary alterations such as cutaneous hyperpigmentation and hair repigmentation have been reported, oral mucosal involvement remains poorly documented.</p><p><strong>Case presentation: </strong>An 80-year-old Black female with multiple myeloma undergoing lenalidomide therapy presented with asymptomatic brown macules on the tongue, hard palate, bilateral buccal mucosa and gingiva. Histopathological examination of an incisional biopsy on the tongue revealed many fine granular, brownish pigmentation of approximately the same size throughout all epithelial layers, as well as collagen fibers, vascular walls, neural tissue, and skeletal striated muscle. These findings represent an unusual pattern of pigment distribution not previously described in patients under lenalidomide therapy.</p><p><strong>Conclusion: </strong>This case emphasizes the need for thorough oral examination in patients undergoing lenalidomide therapy, as early recognition of drug-induced pigmentation is essential for proper diagnosis and management.</p>","PeriodicalId":520636,"journal":{"name":"Head and neck pathology","volume":"20 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13400540/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148582092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Malignant Odontogenic Tumors: A Clinicopathological Study of 53 Cases in Brazil.","authors":"Lorena Paula de Paula, Flávia Sirotheau Correa Pontes, Felipe Paiva Fonseca, Pablo Agustin Vargas, Marcio Ajudarte Lopes, Alan Roger Dos Santos Silva, Jacks Jorge Júnior, Paulo Victor Mendes Penafort, Adalberto Mosqueda-Taylor, Paulo Sérgio da Silva Santos, Vanessa Soares Lara, Cléverson Teixeira Soares, Décio Dos Santos Pinto Júnior, Ramon Ribeiro, Elismauro Francisco de Mendonça, Diego Antônio Costa Arantes, Eneida Franco Vencio, Izadora Fernanda Veiga de Jesus Costa, Flávia Caló de Aquino Xavier, Jean Nunes Dos Santos, Rogério Gondak, Filipe Modolo Siqueira, Juliana Lucena Schussel, Heliton Gustavo de Lima, Ciro Dantas Soares, Hélder Antônio Rebelo Pontes","doi":"10.1007/s12105-026-01952-w","DOIUrl":"10.1007/s12105-026-01952-w","url":null,"abstract":"<p><strong>Objectives: </strong>This study aimed to investigate the clinicopathological features of malignant odontogenic tumors (MOTs) and to provide a comprehensive characterization that enhances the current understanding of this disease group.</p><p><strong>Methods: </strong>MOTs were retrieved from six Brazilian oral pathology services between 2007 and 2025. Demographic, clinical and radiographic data were collected from the charts, and the histological H&E-stained sections were revised by two blinded pathologists; previously available immunohistochemical and molecular findings were retrieved and reviewed in selected cases and the diagnosis was established according to the 2022 World Health Organization classification.</p><p><strong>Results: </strong>A total of 53 malignant odontogenic tumors were identified, predominantly affecting the mandible (83%), with a slight male predominance (male-to-female ratio, 1.12:1) and a mean age of 41.4 years. Ameloblastic carcinoma was the most frequent subtype (58.5%), followed by clear cell odontogenic carcinoma (18.9%), ameloblastic fibrosarcoma (13.2%), primary intraosseous carcinoma (7.5%), and ghost cell odontogenic carcinoma (1.9%).</p><p><strong>Conclusions: </strong>This multicenter review summarizes the main features of malignant odontogenic tumors. Although rare, these tumors often exhibit locally aggressive behavior, highlighting the need for early diagnosis, accurate histopathological evaluation, and standardized reporting with long-term follow-up.</p>","PeriodicalId":520636,"journal":{"name":"Head and neck pathology","volume":"20 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13388572/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148538016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Deep Learning AI Model for Histopathological Diagnosis and Grading of Mucoepidermoid Carcinoma of Salivary Glands (Diagnostic Accuracy Study).","authors":"Doha Ibrahim Abd El Ati, Safa Fathy, Hamza EmadElDin Hamza, Shymaa Hamza","doi":"10.1007/s12105-026-01950-y","DOIUrl":"10.1007/s12105-026-01950-y","url":null,"abstract":"<p><strong>Purpose: </strong>This study aims to evaluate the effectiveness of deep learning AI model in the diagnosis and grading of mucoepidermoid carcinoma.</p><p><strong>Methods: </strong>We developed a multiple instance learning based-deep learning model which consisted of two modules. One to perform slide-level classification of whole slide images into mucoepidermoid carcinoma and non-mucoepidermoid carcinoma classes and the second one to perform grading into low, intermediate, and high grades. A total of 194 whole slide images were included in the study. Of these, 92 corresponded to mucoepidermoid carcinoma, while the remaining 102 represented non-mucoepidermoid carcinoma cases.</p><p><strong>Results: </strong>Our results showed that the classification model achieved 90.62% accuracy, 90.62% macro F1 score, 90.60% weighted F1 score, 91.67% macro precision, 91.18% macro recall. The grading model achieved an accuracy of 73.3%, weighted F1-score of 73.9%, weighted precision of 76.1% and weighted recall of 73.3%.</p><p><strong>Conclusion: </strong>The proposed deep learning classification model achieved promising performance in differentiating mucoepidermoid carcinoma cases. However, the grading model achieved an overall accuracy of 73.3%. Thus, depending on AI solely is still questionable, however it can be used to augment the work of the pathologist.</p>","PeriodicalId":520636,"journal":{"name":"Head and neck pathology","volume":"20 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13388593/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148538028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Calcified Chondroid Mesenchymal Neoplasm of the Temporomandibular Joint Region: Three Cases Illustrating Recent Developments and Diagnostic Pitfalls.","authors":"Darren Yee Shuen Chua, Xinyi Qu, Bengt Fredrik Petersson, Jaslyn Jie Lin Lee, Ming Liang Oon, Nicholas Jin Hong Tan, Abbas Agaimy, Bingcheng Wu","doi":"10.1007/s12105-026-01949-5","DOIUrl":"10.1007/s12105-026-01949-5","url":null,"abstract":"<p><strong>Purpose: </strong>Calcified chondroid mesenchymal neoplasm (CCMN) is a recently described and evolving entity that predominantly arises in the distal extremities andtemporomandibular joint (TMJ) region. CCMN is characterized by FN1 and PDGFRA gene fusions. In the TMJ region, most cases previously described as tophaceous pseudogout (i.e., mass-forming calcium pyrophosphate deposition disease) are now being increasingly recognized as CCMN. There is considerable morphologic overlap between CCMN and tophaceous pseudogout (TPG), and the detection of FN1 and PDGFRA gene rearrangements is critical in distinguishing CCMN from TPG. We aim to identify, from our archival records, cases of CCMN that were previously diagnosed as TPG.</p><p><strong>Methods: </strong>We retrospectively reviewed clinical history and histopathology slides of three cases of TMJ region masses initially diagnosed as TPG, and submitted all three cases for targeted RNA sequencing.</p><p><strong>Results: </strong>Case 1 harbored a canonical FN1::FGFR2 fusion. Case 2 failed targeted RNA sequencing. Case 3 harbored a canonical PDGFRA::USP8 fusion. None of the three cases had clinical history of pseudogout. All three cases were subsequently reclassified as CCMN on review.</p><p><strong>Conclusion: </strong>CCMN should be considered as a differential diagnosis in first presentations of 'tophaceous pseudogout' associated with chondroid metaplasia, with targeted molecular testing done as part of the diagnostic process.</p>","PeriodicalId":520636,"journal":{"name":"Head and neck pathology","volume":"20 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13388602/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148537982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Parotid Cystadenoma Presenting as Recurrent Parotitis: A Five-Case Retrospective Series and Preliminary Clinicopathological Features.","authors":"Mohamed Abdalla, Agboola Ogunbiyi, Mohamed Sundus, Al-Omari Ali","doi":"10.1007/s12105-026-01956-6","DOIUrl":"10.1007/s12105-026-01956-6","url":null,"abstract":"<p><strong>Purpose: </strong>Parotid cystadenoma is an uncommon benign epithelial salivary gland neoplasm. Rarely, it may present with recurrent inflammatory episodes, creating diagnostic uncertainty and operative complexity. To the authors' knowledge, this represents the largest reported case series specifically focused on histologically confirmed parotid cystadenoma presenting with recurrent parotitis. This case series describes five such patients and outlines preliminary clinicopathological features that may support recognition of this presentation, while acknowledging the exploratory nature of the observations.</p><p><strong>Methods: </strong>We performed a retrospective descriptive case series from a specialist parotid surgical practice. Five consecutive patients managed by the primary author with histologically confirmed parotid cystadenoma and a clinical history of recurrent parotitis were included. Clinical presentation, imaging, tissue sampling, operative findings, histopathology, facial nerve status and 12-month follow-up were reviewed from clinical records. No formal diagnostic criteria were developed or validated.</p><p><strong>Results: </strong>All patients had unilateral cystic parotid lesions with recurrent inflammatory symptoms. Imaging demonstrated benign-appearing cystic lesions, varying from well-circumscribed superficial-lobe cysts to multiloculated lesions extending into the deep lobe. Preoperative core biopsy was non-diagnostic in all cases, usually yielding cyst fluid, inflammatory debris or degenerate cells. Surgical excision established the diagnosis in each patient. Histology confirmed cystadenoma, predominantly oncocytic; intraluminal crystalloids were identified in two cases, both associated with suppurative or inflammatory change. No patient had preoperative facial nerve dysfunction. At 12-month follow-up, no recurrence or persistent postoperative facial nerve deficit was recorded in any case.</p><p><strong>Conclusion: </strong>Parotid cystadenoma should be included in the differential diagnosis of recurrent parotitis associated with a cystic parotid lesion, particularly when tissue sampling is inconclusive. The proposed clinicopathological features are preliminary observations from a small retrospective series and require validation in larger cohorts before use as diagnostic criteria.</p>","PeriodicalId":520636,"journal":{"name":"Head and neck pathology","volume":"20 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13376070/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148475744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biphenotypic Sinonasal Sarcomas with Recurrent PAX3::FOXO6 Gene Fusion.","authors":"Rumeal D Whaley, Antonina A Wojcik, Hussam Al-Kateb, Kevin C Halling, Beth A Pitel","doi":"10.1007/s12105-026-01951-x","DOIUrl":"10.1007/s12105-026-01951-x","url":null,"abstract":"<p><strong>Background: </strong>Biphenotypic sinonasal sarcoma (BSNS) typically demonstrates expression of both neural and myogenic markers while harboring PAX3 gene fusions. Reported fusion partners include MAML3, NCOA1, NCOA2, FOXO1, FOXO6, WWTR1, and YAP1. Herein, we report two additional cases of BSNS harboring PAX3::FOXO6 gene fusions to aid in variant classification.</p><p><strong>Case presentation: </strong>Patient 1 was a 37-year-old female and patient 2 was 56-year-old male with BSNS involving the right nasal cavity and left middle turbinate, respectively. Both sarcomas were unencapsulated infiltrative spindle cell neoplasms that demonstrated morphologic features of BSNS. Case 1 demonstrated variable aberrant nuclear accumulation of beta-catenin protein and lacked expression of SMA and S100 protein. Positive reactions were observed with SMA and S100 protein in case 2. RNA sequencing identified PAX3::FOXO6 (exon 7::exon 2) in both cases.</p><p><strong>Conclusion: </strong>The sinonasal location, morphology, and immunophenotype allow for discrimination against competing entities in most cases. In select cases genetic evaluation becomes necessary and to further aid in variant classification and to provide additional support for this rare finding we provide two examples of BSNS harboring PAX3::FOXO6.</p>","PeriodicalId":520636,"journal":{"name":"Head and neck pathology","volume":"20 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13369112/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148440748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oral Diagnosis of Lepromatous Leprosy in a Hyperendemic Region of Brazil.","authors":"Ana Cláudia Garcia Rosa, Marcos Phelipe Araujo Andrade Alves, Regina Garcia Dorta","doi":"10.1007/s12105-026-01945-9","DOIUrl":"10.1007/s12105-026-01945-9","url":null,"abstract":"<p><strong>Background: </strong>Leprosy is a chronic infectious disease caused by Mycobacterium leprae that primarily affects the skin and peripheral nerves. Oral manifestations are rare and typically occur in advanced cases of multibacillary lepromatous leprosy.</p><p><strong>Case presentation: </strong>An 18-year-old male from Tocantins, a hyperendemic region of Brazil, presented with widespread mucocutaneous papulonodular lesions affecting the face and extremities, as well as nodular and ulcerative lesions of the hard and soft palates and the uvula. Histopathological analysis revealed a diffuse subepithelial inflammatory infiltrate predominantly consisting of foamy macrophages exhibiting Virchow-like characteristics. Immunohistochemistry showed diffuse CD68 positivity. Fite-Faraco and Ziehl-Neelsen staining revealed numerous intracytoplasmic acid-fast bacilli. These findings, together with clinical features, established the diagnosis of lepromatous leprosy.</p><p><strong>Conclusion: </strong>Although oral manifestations of leprosy are uncommon, they may represent important diagnostic indicators of advanced multibacillary disease. Oral biopsy, combined with histopathological examination and special stains, remains essential for definitive diagnosis, particularly in hyperendemic regions where other granulomatous infectious diseases may coexist.</p>","PeriodicalId":520636,"journal":{"name":"Head and neck pathology","volume":"20 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13328585/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148379452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}