Pleomorphic adenomas (PA) are the most prevalent benign salivary gland neoplasms. They may occur at any age, with a peak incidence between 40 and 60 years of age. They are more commonly observed in females (60%). These tumors can arise in both the major and minor salivary glands. Approximately 80% of these tumors are diagnosed in the parotid gland, whereas 10% arise in the minor salivary glands, mainly affecting the palates, followed by the lips and cheeks. This report describes two cases of unusual lesions that were diagnosed as (PA) in the minor salivary glands in our department via a review of the relevant literature. The first case involved an 83-year-old man who presented with a slow-growing swelling on the right side of the upper lip, and the second case involved a 45-year-old woman who presented with a slow-growing lesion on the palate. The presence of PA was confirmed histopathologically after surgical resection. Although relatively rare, PA is a benign lesion, the diagnosis of which must be known for appropriate therapeutic management.

OBJECTIVE: The aim of this study was to investigate the potential survival benefits associated with chemoradiotherapy (CRT) as opposed to radiotherapy (RT) in patients with resected high-risk salivary gland cancer (SGC), with a specific focus on determining whether these benefits are influenced by the number of high-risk variables.
METHODS: Patients who underwent surgical treatment for high-risk SGC were retrospectively enrolled and categorized into either CRT or RT groups. The impact of adjuvant therapy on locoregional control (LRC) and overall survival (OS) was assessed using a multivariable Cox model.
RESULTS: A total of 152 patients were included following propensity score-matching. In comparison to RT, CRT did not demonstrate a significant survival advantage in terms of LRC (p = 0.485, HR: 1.14, 95%CI: 0.36-4.22) and OS (p = 0.367, HR: 0.99, 95%CI: 0.17-3.87) in entire population. But among patients with T3/4 stage, high-grade tumors, and 5 or more positive lymph nodes, the addition of chemotherapy to RT significantly (p = 0.042) correlated with a 15% reduction in the risk of cancer recurrence (95%CI: 4-54%). Conversely, in other subgroups with varying combinations of high-risk variables, CRT did not provide additional survival benefits for LRC and OS compared to RT.
CONCLUSIONS: Adjuvant chemotherapy may be considered in conjunction with RT specifically in cases where there is a presence of T3/4 stage, high-grade tumors, and 5 or more metastatic lymph nodes in high-risk SGC.

Microsecretory adenocarcinoma (MSA) is a new type of salivary gland neoplasm identified in the 2022 World Health Organization Classification of Head and Neck Tumour (Skalova et al., Head Neck Pathol 16:40-53, 2022) and is characterized by a unique set of histomorphologic and immunohistochemical features and a recurrent MEF2C::SS18 fusion. MSA was initially misdiagnosed as another salivary gland tumour due to its similar morphology; until recently, only fewer than 50 cases were reported. We present a case of MSA of the hard palate with diverse architectural growth patterns, bland cytological features, abundant basophilic intraluminal secretions and fibromyxoid stroma. The tumour cells were positive for the SOX10, S100, and p63 protein and negative for the p40 protein according to immunohistochemistry. SS18 gene rearrangement was demonstrated via break-apart fluorescence in situ hybridization. We also provided a comprehensive literature review and integrated the clinicopathological features, immunophenotype, and molecular alterations of the disease. A comprehensive understanding of MSA enables us to accurately distinguish and categorize MSA from other salivary gland tumours with analogous morphologies.

Adenoid cystic carcinoma (AdCC) is a slow-growing salivary gland malignancy that relapses frequently. AdCCs of the submandibular gland exhibit unique differences in prognosis and treatment response to adjuvant radiotherapy compared to other sites, yet the role of tumor anatomic subsite on gene expression and tumor immune microenvironment (TIME) composition remains unclear. We used 87 samples, including 48 samples (27 AdCC and 21 normal salivary gland tissue samples) from 4 publicly available AdCC RNA sequencing datasets, a validation set of 33 minor gland AdCCs, and 39 samples from an in-house cohort (30 AdCC and 9 normal salivary gland samples). RNA sequencing data were used for single sample gene set enrichment analysis and TIME deconvolution. Quantitative PCR and multiplex immunofluorescence were performed on the in-house cohort. Wilcoxon rank-sum, nonparametric equality-of-medians tests and linear regression models were used to evaluate tumor subsite differences. AdCCs of different anatomic subsites including parotid, submandibular, sublingual, and minor salivary glands differed with respect to expression of several key tumorigenic pathways. Among the three major salivary glands, the reactive oxygen species (ROS)/nuclear factor erythroid 2-related factor 2 (NRF2) pathway signature was significantly underexpressed in AdCC of submandibular compared to parotid and sublingual glands while this association was not observed among normal glands. Additionally, the NRF2 pathway, whose expression was associated with favorable overall survival, was overexpressed in AdCCs of parotid gland compared to minor and submandibular glands. The TIME deconvolution identified differences in CD4+ T cell populations between AdCC of major and minor glands and natural killer (NK) cells among AdCC of minor, submandibular, and parotid glands while plasma cells were enriched in normal submandibular glands compared to other normal gland controls. Our data reveal key molecular differences in AdCC of different anatomic subsites. The ROS and NRF2 pathways are underexpressed in submandibular and minor AdCCs compared to parotid gland AdCCs, and NRF2 pathway expression is associated with favorable overall survival. The CD4+ T, NK, and plasma cell populations also vary by tumor subsites, suggesting that the observed submandibular AdCC tumor-intrinsic pathway differences may be responsible for influencing the TIME composition and survival differences.

Although rare overall, salivary gland carcinomas (SGCs) are among the most common oral and maxillofacial malignancies. The aim of this study was to develop a machine learning-based model to predict the survival of patients with SGC. Patients in whom SGC was confirmed by histological testing and who underwent primary extirpation at the authors\' institution between 1963 and 2014 were identified. Demographic and clinicopathological data with complete follow-up information were collected for analysis. Feature selection methods were used to determine the correlation between prognosis-related factors and survival in the collected patient data. The collected clinicopathological data and multiple machine learning algorithms were used to develop a survival prediction model. Three machine learning algorithms were applied to construct the prediction models. The area under the receiver operating characteristic curve (AUC) and accuracy were used to measure model performance. The best classification performance was achieved with a LightGBM algorithm (AUC = 0.83, accuracy = 0.91). This model enabled prognostic prediction of patient survival. The model may be useful in developing personalized diagnostic and treatment strategies and formulating individualized follow-up plans, as well as assisting in the communication between doctors and patients, facilitating a better understanding of and compliance with treatment.

BACKGROUND: Neurotrophic tyrosine receptor kinase (NTRK) gene fusions are oncogenic drivers. Using the Auria Biobank in Finland, we aimed to identify and characterize patients with these gene fusions, and describe their clinical and tumor characteristics, treatments received, and outcomes.
METHODS: We evaluated pediatrics with any solid tumor type and adults with colorectal cancer (CRC), non-small cell lung cancer (NSCLC), sarcoma, or salivary gland cancer. We determined tropomyosin receptor kinase (TRK) protein expression by pan-TRK immunohistochemistry (IHC) staining of tumor samples from the Auria Biobank, scored by a certified pathologist. NTRK gene fusion was confirmed by next generation sequencing (NGS). All 2,059 patients were followed-up starting 1 year before their cancer diagnosis.
RESULTS: Frequency of NTRK gene fusion tumors was 3.1% (4/127) in pediatrics, 0.7% (8/1,151) for CRC, 0.3% (1/288) for NSCLC, 0.9% (1/114) for salivary gland cancer, and 0% (0/379) for sarcoma. Among pediatrics there was one case each of fibrosarcoma (TPM3::NTRK1), Ewing\'s sarcoma (LPPR1::NTRK2), primitive neuroectodermal tumor (DAB2IP::NTRK2), and papillary thyroid carcinoma (RAD51B::NTRK3). Among CRC patients, six harbored tumors with NTRK1 fusions (three fused with TPM3), one harbored a NTRK3::GABRG1 fusion, and the other a NTRK2::FXN/LPPR1 fusion. Microsatellite instability was higher in CRC patients with NTRK gene fusion tumors versus wild-type tumors (50.0% vs. 4.4%). Other detected fusions were SGCZ::NTRK3 (NSCLC) and ETV6::NTRK3 (salivary gland cancer). Four patients (three CRC, one NSCLC) received chemotherapy; one patient (with CRC) received radiotherapy.
CONCLUSIONS: NTRK gene fusions are rare in adult CRC, NSCLC, salivary tumors, sarcoma, and pediatric solid tumors.

Objective: To analyze the risk factors affecting regional lymph node metastasis in salivary gland mucoepidermoid carcinoma (MEC) and to establish a nomogram model for individually predicting lymph node metastasis in salivary gland MEC. Methods: The clinical data of 2 152 patients with salivary gland MEC from 1975 to 2020 were collected from the Surveillance, Epidemiology, and End Results (SEER) database of the National Cancer Institute. The collected data were divided into training cohort (1 506 cases) and validation cohort (646 cases) according to the ratio of 7∶3. Single-factor regression and multi-factor logistic regression were used to screen factors related to local lymph node metastasis in salivary gland MEC, with constructing of a nomogram. Calibration curve, receiver operating characteristic (ROC) curve, area under the ROC curve (AUC) and decision curve analysis were used to evaluate model performance in the validation cohort and the total cohort. Statistical tests were performed using SPSS (26.0) and R (4.3.0) software. Results: Multivariate logistic regression results showed that M stage [OR(95%CI):12.360(3.295-46.365), P=0.014], pathological grade Ⅱ、Ⅲ、Ⅳ[OR(95%CI): 1.956(1.329-2.879), 9.654(6.309-14.772), 9.298(6.072-14.238), P<0.001], T staging T2, T3, T4[OR(95%CI): 1.706(0.932-3.124), 3.021(1.790-5.096), 3.311(1.925-5.695), P<0.001], and gender [OR(95%CI):0.759(0.593-0.972), P=0.029] were independent factors affecting local lymph node metastasis in salivary gland MEC. Through verification in the validation cohort and the total cohort, the AUC values were greater than 0.8, and the calibration curve was close to the perfect reference line, proving that the constructed nomogram model had good specificity and sensitivity for predicting local lymph node metastasis in salivary gland MEC. Conclusion: M stage, pathological grade, T stage, and gender are risk factors for predicting regional lymph node metastasis and the established-nomogram has good predictive performance for local lymph node metastasis in salivary gland MEC.
目的： 通过探究影响唾液腺黏液表皮样癌（mucoepidermoid carcinoma，MEC）患者局部淋巴结转移的风险因素，建立可个体化预测唾液腺MEC患者淋巴结转移的列线图模型。 方法： 收集美国国家癌症研究所监测、流行病学及最终结果（Surveillance，Epidemiology，and End Results，SEER）数据库中1975年至2020年2 152例唾液腺MEC患者的临床资料。将其按照7∶3的比例分为训练队列（1 506例）和验证队列（646例）。采用单因素回归以及多因素Logistic回归筛选与唾液腺MEC患者局部淋巴结转移相关的因素，构建列线图。在验证队列及总队列中利用校准曲线、受试者工作特征（ROC）曲线、ROC曲线下面积（AUC）和决策曲线评价模型性能。使用SPSS（26.0）与R（4.3.0）软件进行统计学检验。 结果： 多因素Logistic回归结果显示M分期［OR（95%CI）为12.360（3.295~46.365），P=0.014］、病理分级Ⅱ、Ⅲ、Ⅳ［OR（95%CI）分别为1.956（1.329～2.879）、9.654（6.309～14.772）、9.298（6.072～14.238）,P<0.001］、T分期T2、T3、T4[OR（95%CI）分别为1.706（0.932～3.124）、3.021（1.790～5.096）、3.311（1.925～5.695）,P<0.001］以及性别［OR（95%CI）为0.759（0.593~0.972），P=0.029］是唾液腺MEC患者局部淋巴结转移的影响因素。经过验证队列以及总队列验证，列线图AUC值均大于0.8，校准曲线接近完美参考线。 结论： M分期、病理分级、T分期、性别是预测唾液腺MEC患者局部淋巴结转移的危险因素。据此建立的列线图具有良好的预测性能，可对唾液腺MEC患者局部淋巴结转移的概率进行个体化预测。.

OBJECTIVE: This study describes a large, well-documented case series of salivary gland polymorphous adenocarcinomas (PAC) from a single Brazilian center.
METHODS: Demographic data, clinical presentation, histopathological and immunohistochemical features from 26 cases of PAC were analyzed and discussed in detail.
RESULTS: Most patients were females (n = 21), with a ratio of 1:4.2 (male: female) with a mean age of 58.8 years (ranging from 36 to 84 years). The most common clinical presentation was a fibrocollagenous, firm nodular lesion, with a mean size of 2.46 cm (ranging from 0.5 to 3 cm). Most lesions occurred on the palate (n = 16), followed by buccal mucosa (n = 3), upper lip (n = 3), buccal vestibule (n = 2) and alveolar ridge (n = 1). Histologically, various growth patterns were observed, including tubular, solid, cribriform, papillary, and cystic. Additionally, glomeruloid slit-like structures, mucous, and clear cells were noted. Surface papillary epithelial hyperplasia was observed in a few cases. Nine cases exhibited myxoid and collagenous areas, while two cases showed fusiform areas and another case demonstrated squamous differentiation. Clear cell predominance was noted in two cases, and peri- and intraneural invasion was seen in eight cases. Immunohistochemical analysis revealed positivity for S-100, p63 and CK7, and negativity for p40 in all cases. The Ki-67 proliferation index was markedly low in most cases, with a mean of 2.5%.
CONCLUSIONS: We have provided a broad, detailed description of the clinical and microscopic features of PAC in a large, Brazilian cohort. These findings, in a resource-limited area, may be quite useful for establishing a proper diagnosis.

When neglected for a long time, salivary gland pleomorphic adenoma (PA) can attain a considerable size, increasing the patient\'s morbidity along with the risk of malignant transformation. Very few case reports are available describing PA of the parotid glands presenting as a large cervicofacial mass. We report a case of epithelial myoepithelial carcinoma -a rare subtype of carcinoma ex-PA (Ca-Ex-PA) of non-luminal differentiation, that developed over a long period in a primary PA of the parotid gland and presented as a giant cervicofacial mass.

Salivary gland squamous cell carcinomas (SG-SCCs) constitute a rare type of head and neck cancer which is linked to poor prognosis. Due to their low frequency, the molecular mechanisms responsible for their aggressiveness are poorly understood. In this work we studied the role of the phosphatase DUSP1, a negative regulator of MAPK activity, in controlling SG-SCC progression. We generated DUSP1 KO clones in A253 human cells. These clones showed a reduced ability to grow in 2D, self-renew in ECM matrices and to form tumors in immunodeficient mice. This was caused by an overactivation of the stress and apoptosis kinase JNK1/2 in DUSP1-/+ clones. Interestingly, RNAseq analysis revealed that the expression of SOX2, a well-known self-renewal gene was decreased at the mRNA and protein levels in DUSP1-/+ cells. Unexpectedly, CRISPR-KO of SOX2 did not recapitulate DUSP1-/+ phenotype, and SOX2-null cells had an enhanced ability to self-renew and to form tumors in mice. Gene expression analysis demonstrated that SOX2-null cells have a decreased squamous differentiation profile -losing TP63 expression- and an increased migratory phenotype, with an enhanced epithelial to mesenchymal transition signature. In summary, our data indicates that DUSP1 and SOX2 have opposite functions in SG-SCC, being DUSP1 necessary for tumor growth and SOX2 dispensable showing a tumor suppressor function. Our data suggest that the combined expression of SOX2 and DUSP1 could be a useful biomarker to predict progression in patients with SG-SCCs.