Malignant Salivary Gland Tumors Research Articles

Oncologic outcomes of the most prevalent major salivary gland cancers: retrospective cohort study from single center

BackgroundThe preoperative diagnosis of salivary gland cancer (SGC) is crucial for the application of appropriate treatment, particularly involving the extension of the resection.MethodsRetrospective search of medical database identified 116 patients treated surgically with malignant tumors of salivary gland between 2010 and 2020. Analysis included the demographical data, clinical course, type of surgical and adjuvant treatment, histology type and margin status, perivascular invasion (LVI), perineural invasion (PNI), metastatic lymph nodes (LN). Facial nerve function, recurrence-free and overall survival were evaluated. Adequate statistics were used for data analysis.ResultsThe final cohort included 63 SGC patients, with adenoid cystic carcinoma the most common pathological type (27%, n = 17), followed by adenocarcinoma (17.4% n = 11). T1 and T2 patients accounted for majority cases (n = 46). The lymph node metastases were confirmed with the histopathology in 31.7% (n = 20). Distant metastases were observed in 4.8% of cases (n = 3). 38% (n = 24) of SGC were treated selectively with surgery, 49.2% (n = 31) had postoperative radiotherapy and 15.9% (n = 10)—radio-chemotherapy. The final facial nerve function was impaired in 38% of patients. Mean overall survival (OS) for all patients was 108.7 (± 132.1) months, and was the most favorable for acinar cell carcinoma (118.9 ± 45.4) and the poorest for squamous cell carcinoma (44 ± 32). Cox regression analysis of disease-free survival and OS identified significant association only with patients’ age over 65 years, the hazard ratio of 7.955 and 6.486, respectively.ConclusionsThe efficacy of treatment modalities for SGC should be verified with regard to the histopathological type, but also the patients’ age should be taken into account.

Unique Presentation of Rare Cervical Sympathetic Chain Schwannoma

We describe a unique case of a cervical sympathetic chain schwannoma that presented as an ambiguous oropharyngeal mass with a differential of a benign or malignant salivary gland tumor or neurogenic tumor. Consideration of a malignant salivary gland mass led us to modify our diagnostic approach so as not to risk seeding a potential malignancy and harming the patient. This article also highlights the distinct imaging findings of neurogenic tumors of the neck that are helpful in appropriately diagnosing these tumors.

Salivary gland tumors: an audit from a tertiary care centre in Northern India.

Salivary gland tumors are relatively rare and can exhibit various clinical behaviors. The study aims to understand the natural history, pathology, diagnostic workup, and treatment strategies for these tumors to improve patient outcomes. The audit included patients with salivary gland tumors detected through radiology or cytology. Patients underwent surgery, with some receiving adjuvant treatment. Demographic information, treatment interventions, and survival outcomes were analyzed using SPSS software. A total 89 as malignant salivart gland tumours were audited Malignant tumors were predominantly found in the parotid gland, with fewer cases in the minor salivary gland and submandibular gland.The median age of presentation was 47 years, and the majority of patients were male. The study examined various pathological and clinical factors, including tumor stage, nodal status, and the presence of facial palsy. Surgical procedures and histological types of tumors were documented. Adverse histological features like positive margins, lymph node positivity, lympho-vascular invasion, extracapsular spread, and perineural invasion were noted. POSTOP RT was administered to high-risk patients. Most malignant salivary gland tumors were found in the parotid gland, while minor salivary gland tumors were underrepresented in the audit. Surgical practices were diverse. Radiotherapy protocols were relatively standardized. The study found that certain histological features, such as lymph node positivity, margin positivity, lympho-vascular invasion, perineural invasion, and extracapsular spread, were associated with adverse effects on DFS and OS. The findings suggest that specific histological features, including LVI and ECE have emerged as independent prognostic factors for DFS and OS.

Differentiation of salivary gland tumors using diffusion-weighted image-based virtual MR elastography: A pilot study.

Differentiation among benign salivary gland tumors, Warthin tumors, and malignant salivary gland tumors is crucial to treatment planning and predicting patient prognosis. However, differentiation of those tumors using imaging findings remains difficult. This study evaluated the usefulness of elasticity determined from Diffusion-weighted image (DWI)-based virtual MR elastography (MRE) compared with conventional MRI findings in differentiating the tumors. This study included 17 benign salivary gland tumors, six Warthin tumors, and 11 malignant salivary gland tumors scanned on neck MRI. The long and short diameters, T1 and T2 signal intensities, tumor margins, ADC values, and elasticity from DWI-based virtual MRE of the tumors were evaluated. The interobserver agreement in measuring tumor elasticity and the ROC curves were also assessed. The long and short diameters and the T1 and T2 signal intensities showed no significant difference among the three tumor groups. Tumor margins and the mean ADC values showed significant differences among some tumor groups. The elasticity from virtual MRE showed significant differences among all three tumor groups and the interobserver agreement was excellent. The area under the ROC curves of the elasticity were higher than those of tumor margins and mean ADC values. Elasticity values based on DWI-based virtual MRE of benign salivary gland tumors, Warthin tumors, and malignant salivary gland tumors were significantly different. The elasticity of Warthin tumors was the highest and that of benign tumors was the lowest. The elasticity from DWI-based virtual MRE may aid in the differential diagnosis of salivary gland tumors.

The tumor microenvironment of benign and malignant salivary gland tumors.

Treatment of salivary gland tumors (SGTs) remains challenging. Little is known about the immune landscape of SGTs. We aimed to characterize the tumor microenvironment in benign and malignant SGTs. Eleven benign and nine malignant tumors were collected from patients undergoing curative intent surgery. Specimens were analyzed using mass cytometry by time-of-flight. Immune cell populations were manually gated, and T cells were clustered using the FlowSOM algorithm. Population frequencies were compared between high-grade and low-grade malignancies, corrected for multiple hypothesis testing. There were trends towards increased CD4+ and CD8+ T cells among malignant tumors. High-grade malignancies exhibited trends towards higher frequencies of CD8+ PD-1+ CD39+ CD103+ exhausted T cells, CD4+ FoxP3+ TCF-1+ CD127- Tregs, and CD69+ CD25- CD4+ T cells compared to low-grade malignancies. SGTs exhibit significant immunologic diversity. High-grade malignancies tended to have greater infiltration of exhausted CD8+ T cells and Tregs, which may guide future studies for immunotherapy strategies.

Radical Resection of Malignant Tumors of Major Salivary Glands: Is This Possible?

In primary therapy, a universally recognized surgical indication applies to all tumors of the salivary glands. According to the classic rule, radical resection of a head and neck tumor requires clean margins of at least 5 mm, although recent studies have shown that for certain locations, 1 mm may be sufficient. In the surgical resection of a tumor of the salivary glands, especially of the parotid gland, can these rules be respected? Owing to the complex branching and connections of the facial nerve within the parotid gland, even a medium-sized malignant tumor may be in contact with a branch of the nerve, thus raising the question of its preservation. The facial nerve is so important from a functional and aesthetic point of view that it is commonly believed that it should be preserved unless it is incorporated into the tumor. This is a compromise between an oncological resection, that is, the complete excision of the tumor with no residual cancer cells left behind, and quality of life. Almost all authors try to overcome this lack of radicality by indicating postoperative (chemo)radiotherapy. In this article, the pros and cons of nerve preservation will be analyzed by examining the published studies on this topic.

A Clinicopathological Study of Salivary Gland Lesions and Immunohistochemical Expression of Bcl2 in Benign and Malignant Salivary Gland Neoplasms

Introduction Salivary glands neoplasms (SGNs) are rare tumors and comprise approximately 3-10% of the neoplasms of the head and neck region and 1% of the neoplasms of the whole body(1) . Annual global incidence of SGNs is between 0.4 to 13.5 cases per 1, 00,000 individuals(2) . Among these, malignant salivary gland neoplasms (MSGNs) are 0.40 to 0.65 per 1, 00,000 cases(3) . MSGNs are 0.3% of all malignancies(4) . Early diagnosis of MSGNs play an important role in better management of these tumors(5) . Fine-needle aspiration cytology (FNAC) is used as a screening and early diagnostic tool in SGNs however its role is limited(6) . Accurate diagnosis depends upon the histological evaluation of SGNs

The immunohistochemical expression Ki-67 In Polymorphous Low Grade Adenocarcinoma of the Salivary Glands

Background: Polymorphous Low Grade Adenocarcinoma is a rare malignant tumor of minor salivary glands. It has an unique histopathological, clinical and behavioural features. Most of its incidence has been presented in the palate. It shows a variety of growth patterns within the same one lesion, including cribriform, tubular, and solid areas that may mimic adenoid cystic carcinoma. The tumor cells histologically are characterized by lacking of nuclear atypical and hyperchromatism with rare mitoses. However, the prognosis of this tumor is good because of its low grade, although it has an unpredictable potential to metastasize.
 Objectives: To evaluate the histopathological expression of Ki-67 proliferation antigen in Polymorphous low grade adenocarcinoma and compare the results with the clinicopathological parameters and grading of the tumors.
 Materials and Methods: This study includes 20 cases with Polymorphous Low Grade Adenocarcinoma of minor salivary glands diagnosed histopathologically and treated surgically, were investigated for the immunohistochemical expression of Ki-67 antigen. Immunohistochemical staining was performed using a Labeled Strept- Avidin Biotin method (LSAB) and 0.05 (two-sided) was the level of significance.
 Results: Twenty cases of Polymorphous Low Grade Adenocarcinoma of salivary glands were histologically diagnosed in this retrospective study to evaluate the expression of Ki-67. The mean age for patients with PLGA was nearly (50.6). (12) (60%) cases were males and (8) (40%) cases were females and also male to female ratio was (1.5:1).
 In regarding to site distribution, the most common site was the palate followed by the submandibular gland and floor of the mouth. 
 Conclusions: it was observed that there is a higher rate of cellular proliferation in malignant tumors with high grade, indicating their role in the malignancy and aggressive behavior of these tumors.

Wnt/β-catenin-C-kit axis may play a role in adenoid cystic carcinoma prognostication

Adenoid cystic carcinoma (ACC) is one of the most common malignant salivary gland tumors. ACC is composed of myoepithelial and epithelial neoplastic cells which grow slowly and have a tendency for neural invasion. The long term prognosis is still relatively poor. Although several gene abnormalities, such as fusions involving MYB or MYBL1 oncogenes and the transcription factor gene NFIB, and overexpression of KIT have been reported in ACC, their precise functions in the pathogenesis of ACC remain unclear. We recently demonstrated that the elevated expression of Semaphorin 3A (SEMA3A), specifically expressed in myoepithelial neoplastic cells, might function as a novel oncogene-related molecule to enhance cell proliferation through activated AKT signaling in 9/10 (90%) ACC cases. In the current study, the patient with ACC whose tumor was negative for SEMA3A in the previous study, revisited our hospital with late metastasis of ACC to the cervical lymph node eight years after surgical resection of the primary tumor. We characterized this recurrent ACC, and compared it with the primary ACC using immunohistochemical methods. In the recurrent ACC, the duct lining epithelial cells, not myoepithelial neoplastic cells, showed an elevated Ki-67 index and increased cell membrane expression of C-kit, along with the expression of phosphorylated ERK. Late metastasis ACC specimens were not positive for β-catenin and lymphocyte enhancer binding factor 1 (LEF1), which were detected in the nuclei of perineural infiltrating cells in primary ACC cells. In addition, experiments with the GSK-3 inhibitor revealed that β-catenin pathway suppressed not only KIT expression but also proliferation of ACC cells. Moreover, stem cell factor (SCF; also known as KIT ligand, KITL) induced ERK activation in ACC cells. These results suggest that inactivation of Wnt/β-catenin signaling may promote C-kit-ERK signaling and cell proliferation of in metastatic ACC.

Polymorphous Adenocarcinoma: A Systematic Review of the Literature and Presentation of Two Cases in a Less-Considered Anatomical Site.

Polymorphous adenocarcinoma (PAC) is the second-most common malignant tumour of the minor salivary glands. Although PAC predominantly affects the palate, it can also involve the buccal mucosa. This systematic review aims to investigate the literature data about PAC. Furthermore, we report two cases of patients affected by PAC in an infrequently considered anatomical site. According to PRISMA guidelines, a systematic review search was conducted on PubMed, Scopus, and Web of Science. Observational studies conducted on patients with a histological diagnosis of PAC were selected and analysed. Furthermore, two cases of patients with PAC affecting the buccal mucosa were reported. Twenty-nine studies were included, and 143 patients affected by PAC were analysed (62 males, 75 females, and 6 undefined, with a mean age of 57.4 ± 14.5 years). The palate was the most affected site (99/143, 69.2%), followed by the buccal mucosa (12/143, 8.4%). Moreover, we report two cases of patients with PAC affecting the buccal mucosa (one male and one female, with a mean age of 70.5 ± 2.5 years). The present study underscores the importance of considering the buccal mucosa as a possible location of minor salivary gland tumours; although it is a less-considered affliction, it is not uncommon.

Malignant salivary gland tumors: agreement between fine needle aspiration biopsy, incisional biopsy and final histopathological diagnostic.

Incisional biopsy is indicated for intraoral tumors, but it is a contraindicated surgical procedure for major salivary glands. To avoid complications and facilitate diagnosis, fine needle aspiration biopsy (FNAB) is a type of biopsy widely used for preoperative diagnosis in these glands. The aim of this study was to analyze the agreement between the diagnosis by FNAB (major glands), incisional biopsy (minor glands) and histopathological analysis of the surgical specimen in salivary gland tumors from a database (medical records) of patients treated in a cancer treatment reference center in the Northeast region of Brazil. The sample consisted of 110 cases, being 86 of them malignant tumors in major salivary glands (parotid gland=73; submandibular gland=13) and 24 cases in minor salivary glands (palate). The female gender was the most affected (57.3%), especially in patients over 60 years (42.7%). In the TNM classification, 41.8% of the cases were in T2 at the time of diagnosis, with most of the regional lymph nodes in N0 (85.5%) and 87.3% of the cases in M0. FNAB was able to identify malignant neoplasms in 68.6% of the cases (n=59), while incisional biopsy in palatal tumors obtained agreement of 75% of the cases (n=18). The analysis revealed that tumors classified as T3-T4 (p=0.012) showed greater agreement between pre- and post-surgical diagnosis. The results obtained in this study indicate that FNAB has similar accuracy to incisional biopsy in providing satisfactory preoperative diagnoses of malignant tumors in salivary glands.

Impaired intratumoral dendritic cell function and potential predictive value of dendritic cell markers for metastasis in malignant salivary gland tumors.

The differentiation between primary and metastatic salivary gland neoplasms (SGNs) helps in determining appropriate management strategies, including the need for additional diagnostic tests, surveillance, or aggressive treatment. The purpose of this study was to identify and quantify the immature and mature dendritic cells (DCs) in metastatic and no metastatic SGNs and determine its association with clinicopathological findings. Cross-sectional, observational, and descriptive study that includes 33 malignant salivary gland neoplasms [MSGN (6, 18.1% metastatic)], and 22 pleomorphic adenomas (PA), as a control group. Clinical and histopathological characteristics were obtained. Immunohistochemistry for human leukocyte antigen D-related (HLA-DR), CD1a, CD83, and Ki-67 proteins was done. Positive intra- and peritumoral DCs were counted. Individuals with MSGN had a lower density of intratumoral HLA-DR+ cells than those with PA (p=0.001), Ki-67 immunostaining was significantly higher in MSGN than in PA (6% vs. 1.4%, p<0.001). Metastatic MSGN showed less intratumoral CD1a+ than non-metastatic (3.2 vs. 165.1, p=0.001). No differences in intra- and peritumoral CD83+ cells were found between benign and malignant SGN. These results suggest that the immune-protective function of intratumoral DCs is compromised in MSGNs. DCs markers may represent useful prediction tools for metastases in salivary gland malignancies, with crucial implications in the implementation of appropriate disease management strategies.

Evaluation of cell proliferation marker CDC-7 in salivary adenoid cystic carcinoma

BackgroundAdenoid cystic carcinoma (AdCC) is considered one of the most common destructive types of malignant salivary gland tumor that have high affinity to perineural invasion (PNI). This study was conducted to access different histological features of AdCC, and assessment of the immunohistochemical expression of CDC-7. MethodsThirty formalin-fixed paraffin incorporated tissue blocks of AdCC were classified according to the WHO histopathological types. The immune-expression of CDC-7 positive area was evaluated according to percentage area as following: Negative = 0 %, Weak = 1–10 %, Moderate = 11–49 %, and Strong = 50–100. The correlations between expression of the marker and different clinico-pathological variables were investigated using Chi-square (χ2) test. The P‐value ≤ 0.05 was considered statistically significant. ResultsThe expression of CDC-7 revealed statistical significant difference between the different tumor types (p ≤ 0.05). ConclusionThe biological behavior of AdCC can be predicated from the expression of CDC-7.

Epithelial malignant tumors of the parotid salivary glands in children and adolescents

The article provides data on epithelial malignant tumors of the parotid salivary glands in children and adolescents. We present a historical background and modern classification proposed by the World Health Organization in 2022. We present the evolution of surgical and non-surgical treatment methods used in pediatric oncology.

Impact of Sarcopenia on Survival of Patients With Malignant Salivary Glands Tumors.

Malignant salivary glands tumors (MSGTs) are a quite rare and heterogeneous group of tumors. Management of these lesions remains controversial and challenging. Thus, finding new prognostic factors that can help to guide the decision-making process, appears to be paramount. The aim of this study was to evaluate the prognostic performance of preoperative sarcopenia to stratify MSGTs patients at high risk of disease progression. Retrospective study. A single-institution analysis (Maxillo-facial Surgery Unit, University of Naples Federico II). The study consists of a retrospective analysis of 74 patients surgically treated for MSGTs. For all patients, the skeletal muscle index (SMI) was calculated and sarcopenia was defined as SMI < 41 in females and <43 in males. The correlation between sarcopenia and tumor variables was analyzed. The prognostic performance of sarcopenia was evaluated through survival Kaplan-Meier curves. Sarcopenia resulted statistically related to age (P < .001), tumor size (P < .001), lymph node metastases (P < .001), and American Joint Committee on Cancer tumor, node, metastasis stage (P < .001). Kaplan-Meier survival curves show that 47.3% of sarcopenic patients died before their final follow-up. Data obtained from our study seem to confirm the correlation between sarcopenia and other high-risk features. The early detection of sarcopenia in patients with negative prognostic factors could be used to implement the support therapeutic strategies aimed at restore the clinical conditions of the patients. Sarcopenia may be routinely investigated before surgery to suggest the implementation of precautionary therapeutic strategies to improve the standard treatment response, reducing possible complications.

Epidemiological Profile of Salivary Gland Tumors in Southern Iranian Population: A Retrospective Study of 405 Cases.

Salivary gland tumors (SGTs) are a rare and diverse group of tumors that account for 3 to 10% of all head and neck malignancies. We aimed to conduct a comprehensive epidemiological analysis of SGTs in the south of Iran and compare the findings with previous reports from Iran and other parts of the world. Using a retrospective study, 405 patients diagnosed with SGTs were observed over an eight-year period between April 2013 and October 2021 in Shiraz, Iran. Patients' demographic and clinicopathological features were obtained from patients' records. Quantitative and descriptive data analysis was performed using SPSS software. There were 302 benign (74.5%) and 103 (25.4%) malignant SGTs. Pleomorphic adenoma and Warthin's tumors were the most common benign SGTs (70.5% and 21.5%, respectively). The most common malignant SGTs were mucoepidermoid carcinoma and adenoid cystic carcinoma (26.2% and 22.3%, respectively). There was a statistically significant association between tumor origin and its malignancy status (p < 0.001). In addition, the results indicated that benign tumors were most commonly detected in the parotid gland (p < 0.05). The benign tumors were more frequently observed among the younger population (p = 0.006). In summary, the findings of the current study were mainly consistent with the previous reports from Iran and the rest of the world. Benign tumors were the most prevalent type of SGTs, and the parotid gland was the most common site. While the majority of cases that developed from the major salivary glands were benign, all the minor SGTs were malignant. Older patients were more likely to develop malignant tumors compared to younger ones. This study provides insights into the prevalence, age-related incidence, gender distribution, and geographic variation of salivary gland tumors. This can be instrumental to develop a guideline for screening, diagnosis, and determining an optimal treatment.

Salivary Gland Secretory Carcinoma; Review of 13 Years World-Wide Experience and Meta-Analysis.

Secretory Carcinoma is a malignant salivary gland tumor, initially described in 2010. This rare tumor is associated with the translocation t(12;15) (p13;q25), resulting in the fusion gene ETV6-NTRK3. Since this tumor is quite rare, most publications describe only small cohorts of patients. We aimed to investigate the clinical, pathological, and prognostic features of this newly defined malignant entity. Pubmed, Google Scholar, and Web of Science databases. All published articles between 2010 and 2023 were reviewed. Search terms included the terms "Mammary Analogue Secretory Carcinoma" and "Secretory Carcinoma". All articles published in English reporting on Secretory Carcinoma of salivary glands were retrieved. One-hundred and 12 retrospective articles reporting a total of 674 patients were included, with 52% males and a mean age of 44.9 ± 18.9. The event rate for patients with advanced-stage disease (Stage 3/4) at presentation was 24.1% (95% CI 17.6%-31.9%, I2 = 9.2%), 14.6% for regional metastases (95% CI 10.5%-20%, I2 = 12%), and the event rate of distant metastasis was 8.4% (95% CI 5.5%-12.7%, I2 = 4.2%). Adjuvant radiotherapy was administered for 30.3% of patients (95% CI 24.1%-37.2%, I2 = 21.5%). The recurrence rate was 19% (95% CI 15.1%-23.8%, I2 = 5%). Survival outcomes showed a 17.2% death of disease rate for Secretory Carcinoma patients (95% CI 13.5%-21.8%, I2 = 7.3%). Secretory Carcinoma is a rare and relatively newly defined entity arising in the parotid gland most commonly. Characterized as a low-grade tumor, the majority of patients are diagnosed at an early stage, without regional or distant disease, and the prognosis is relatively good. NA Laryngoscope, 134:1716-1724, 2024.

Diagnosis of Salivary Gland Tumors Using Transfer Learning with Fine-Tuning and Gradual Unfreezing.

Ultrasound is the primary tool for evaluating salivary gland tumors (SGTs); however, tumor diagnosis currently relies on subjective features. This study aimed to establish an objective ultrasound diagnostic method using deep learning. We collected 446 benign and 223 malignant SGT ultrasound images in the training/validation set and 119 benign and 44 malignant SGT ultrasound images in the testing set. We trained convolutional neural network (CNN) models from scratch and employed transfer learning (TL) with fine-tuning and gradual unfreezing to classify malignant and benign SGTs. The diagnostic performances of these models were compared. By utilizing the pretrained ResNet50V2 with fine-tuning and gradual unfreezing, we achieved a 5-fold average validation accuracy of 0.920. The diagnostic performance on the testing set demonstrated an accuracy of 89.0%, a sensitivity of 81.8%, a specificity of 91.6%, a positive predictive value of 78.3%, and a negative predictive value of 93.2%. This performance surpasses that of other models in our study. The corresponding Grad-CAM visualizations were also presented to provide explanations for the diagnosis. This study presents an effective and objective ultrasound method for distinguishing between malignant and benign SGTs, which could assist in preoperative evaluation.

Central mucoepidermoid carcinoma of maxilla a case report and review of literature

MEC is the most commonly occurring malignant salivary gland neoplasm, comprising 2.8–15% of all salivary gland tumors. Its behavior is like mucoepidermoid cancers elsewhere and maxillary cancers in general. These cancers typically impact the mandible and exhibit histological characteristics indicating low-grade malignancy. This paper reports the case of 50-year-old female with facial swelling, which on FNAC showed intermediate-grade epithelial malignancy. mucoepidermoid carcinoma. MRI showed lytic lesion in right maxilla. She underwent right subtotal maxillectomy and had good prognosis on one year follow up.

Radiomics Analysis in Characterization of Salivary Gland Tumors on MRI: A Systematic Review.

Radiomics analysis can potentially characterize salivary gland tumors (SGTs) on magnetic resonance imaging (MRI). The procedures for radiomics analysis were various, and no consistent performances were reported. This review evaluated the methodologies and performances of studies using radiomics analysis to characterize SGTs on MRI. We systematically reviewed studies published until July 2023, which employed radiomics analysis to characterize SGTs on MRI. In total, 14 of 98 studies were eligible. Each study examined 23-334 benign and 8-56 malignant SGTs. Least absolute shrinkage and selection operator (LASSO) was the most common feature selection method (in eight studies). Eleven studies confirmed the stability of selected features using cross-validation or bootstrap. Nine classifiers were used to build models that achieved area under the curves (AUCs) of 0.74 to 1.00 for characterizing benign and malignant SGTs and 0.80 to 0.96 for characterizing pleomorphic adenomas and Warthin's tumors. Performances were validated using cross-validation, internal, and external datasets in four, six, and two studies, respectively. No single feature consistently appeared in the final models across the studies. No standardized procedure was used for radiomics analysis in characterizing SGTs on MRIs, and various models were proposed. The need for a standard procedure for radiomics analysis is emphasized.