Salivary gland tumors: a diagnostic dilemma!

The Role of Blood Inflammatory Markers in Salivary Gland Carcinoma: A Scoping Review

Background/Objectives: Malignant carcinomas of the salivary glands account for approximately 1 to 7% of all head and neck malignancies and approximately 0.3% of all malignant neoplasms. Recently, the scientific community has focused on finding biomarkers that could tailor the treatment for patients with this type of cancer. The neutrophil-lymphocyte ratio (NLR) was the first marker studied and it is one of the most widely used; the platelet-lymphocyte ratio (PLR), the systemic immune inflammation index (SII) and the systemic inflammatory response index (SIRI) have recently emerged as important biomarkers. The aim of this scoping review is to evaluate the role of inflammatory biomarkers in the management of salivary gland malignancies. Methods: A review of the English literature on inflammatory blood markers in major salivary gland cancer was performed using PubMed, Scopus, and Google Scholar databases. The literature review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines for scoping reviews. Results: Eleven full-text articles were included in this review, for a total of 1356 patients in which the role of inflammatory biomarkers (NLR, PLR, SII or SIRI) for the diagnosis and prognosis of salivary gland cancer was assessed. NLR (i) was evaluated in all the studies; (ii) it contributed to the diagnosis and prognosis of both adult and pediatric patients and (iii) can be considered the main biomarker, even if a universal cut-off range is not available yet. PLR, SII and SIRI were introduced more recently and were evaluated only in some studies. Conclusions: The findings of this study suggest that elevated NLR values, regardless of age, are more frequently associated with malignancy and a poor prognosis. Further studies are necessary to evaluate the role of biomarkers other than NLR, and to identify universal and practical cut-off values.

High-frequency shear wave MR elastography of parotid glands: custom driver design and preliminary results

Parotid glands are one of the most common sites for salivary gland tumors. Conventional imaging techniques have limited usefulness in the quantitative assessment of the parotid glands, making it difficult to differentiate between healthy tissue and tumors, as well as between benign and malignant tumors. Magnetic resonance elastography (MRE) is a non-invasive technique that may potentially overcome these limitations. Nevertheless, due to the size of the parotid gland, increased elastographic resolution is required. This may be achieved by applying shear waves at higher frequencies. However, it also results in stronger attenuation, making the illumination of the parotid challenging. Here, we describe a novel passive driver tailored to the anatomy of the human face, which minimizes the distance shear waves need to travel from the source to the area of interest and thus decreases shear wave attenuation, making high-frequency shear wave MRE feasible.

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.

S, Kripesh G. A Study on Myloblastosis Gene (MYB) in Adenoid Cystic Carcinoma Using the New IHC Marker MYB (SZ04-81)

Background and aim: Adenoid cystic carcinoma is one of the most common malignant neoplasms of the salivary gland. It has overlapping histological features with other salivary gland tumors. MYB is a nuclear marker which is known to be expressed in Adenoid cystic carcinoma. In this study we aim to determine the sensitivity and specificity of MYB IHC marker to differentiate Adenoid cystic carcinoma from other benign and malignant salivary gland tumors. Materials and method: This is a retrospective case control study on the paraffin blocks of 78 cases of salivary gland tumors obtained over a period of 5 years. MYB Ser11 monoclonal antibody of clone SZ04-81 IHC, a nuclear marker was done on all cases. The results observed was tabulated and statistical analysis was done to calculate the sensitivity and specificity of the MYB IHC marker. Results: The mean age group of Adenoid cystic carcinoma was 45 years with a female preponderance. 60% of the cases of Adenoid cystic carcinoma were from minor salivary glands spread across various sites. The sensitivity and specificity of the MYB IHC marker were statistically analyzed and found to be 93.9% and 97.8% respectively. Conclusion: The present study shows substantial expression of MYB immunohistochemical marker in Adenoid cystic carcinoma, with a very high sensitivity and specificity obtained using the clone SZ04-81. Thus this marker can be used in the diagnosis of adenoid cystic carcinoma. However, correlation with H & E and FISH studies are required.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-03471-4.

Support Tools in the Differential Diagnosis of Salivary Gland Tumors through Inflammatory Biomarkers and Radiomics Metrics: A Preliminary Study

BACKGROUND

The purpose of this study was to investigate how the systemic inflammation response index (SIRI), systemic immune-inflammation index (SII), neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR), and radiomic metrics (quantitative descriptors of image content) extracted from MRI sequences by machine learning increase the efficacy of proper presurgical differentiation between benign and malignant salivary gland tumors.

METHODS

A retrospective study of 117 patients with salivary gland tumors was conducted between January 2015 and November 2022. Univariate analyses with nonparametric tests and multivariate analyses with machine learning approaches were used.

RESULTS

Inflammatory biomarkers showed statistically significant differences (p < 0.05) in the Kruskal-Wallis test based on median values in discriminating Warthin tumors from pleomorphic adenoma and malignancies. The accuracy of NLR, PLR, SII, and SIRI was 0.88, 0.74, 0.76, and 0.83, respectively. Analysis of radiomic metrics to discriminate Warthin tumors from pleomorphic adenoma and malignancies showed statistically significant differences (p < 0.05) in nine radiomic features. The best multivariate analysis result was obtained from an SVM model with 86% accuracy, 68% sensitivity, and 91% specificity for six features.

CONCLUSIONS

Inflammatory biomarkers and radiomic features can comparably support a pre-surgical differential diagnosis.

Immunohistochemical comparative analysis of tumor stem cell biomarkers in pleomorphic adenoma, adenoid cystic carcinoma and mucoepidermoid carcinoma of salivary glands

OBJECTIVE

This study aimed to compare the immunoexpression profile of tumor stem cell (TSC) biomarkers CD44, aldehyde dehydrogenase 1 (ALDH1), OCT4, and SOX2 in salivary gland tumors (SGTs).

STUDY DESIGN

Sixty tissue specimens of SGTs, including 20 pleomorphic adenomas, 20 adenoid cystic carcinomas (ACCs), and 20 mucoepidermoid carcinomas, in addition to 4 samples of normal glandular tissue, were subjected to immunohistochemistry. The expression of the biomarkers in the parenchyma and stroma was evaluated. Data were analyzed statistically by nonparametric tests (P < .05).

RESULTS

Higher parenchymal expression of ALDH1, OCT4, and SOX2 was observed in pleomorphic adenomas, ACCs, and mucoepidermoid carcinomas, respectively. Most ACCs did not express ALDH1. Higher immunoexpression of ALDH1 in major SGTs (P = .021) and of OCT4 in minor SGTs (P = .011) was found. Immunoexpression of SOX2 was related to lesions without myoepithelial differentiation (P < .001) and malignant behavior (P = .002). Furthermore, OCT4 was related to myoepithelial differentiation (P = .009). CD44 expression was related to a better prognosis. Stromal immunoexpressions of CD44, ALDH1, and OCT4 were higher in malignant SGTs.

CONCLUSIONS

Our findings suggest the participation of TSCs in the pathogenesis of SGTs. We emphasize the need for further investigations into the presence and role of TSCs in the stroma of these lesions.

Analysis of Cytological Misdiagnosis and Oversight of Adenoid Cystic Carcinoma of Salivary Gland

OBJECTIVE

In this article on adenoid cystic carcinoma (ACC) of salivary gland, we intend to summarize the causes of misdiagnosis and oversight of ACC hoping to improve cytological diagnostic accuracy, clinical management and patient treatment.

METHODS

The study retrospectively reviewed 32 patients with ACC of salivary gland, registered at the Affiliated Hospital of Southwest Medical University from July 2014 to June 2021. These cases were diagnosed by FNA and surgical excision biopsy. All cytopathological results were retrospectively categorized according to Milan system for reporting salivary gland cytopathology (MSRSGC). The accuracy of FNA was verified by surgical excision biopsy.

RESULTS

Of these 32 patients, 16 (50.0%) cases were male, and 16 (50.0%) were female. Their age ranged from 21 to 79 years, with an average age of 50.32 years. The highest incidence (15/32, 46.9%) of ACC was observed in patients between 41 and 50 years of age. 10 cases (31.3%) occurred in the parotid gland, 9 cases (28.1%) in the submandibular gland, 9 cases (28.1%) in the sublingual gland, 3 cases (9.4%) in the palate, and 1 case (3.1%) in the lip. Among the 32 cases of ACC, 23 cases (71.9%) were classified to VI, 4 cases (12.5%) to IVa, and 5 cases (15.6%) to II by MSRSGC. A comparison of the FNA results with biopsy showed that the accuracy of FNA in ACC of salivary gland is 71.9%. Being able to identify the cytomorphological features is the key factor for accurate diagnosis of ACC of the salivary gland.

CONCLUSION

Our results confirm that FNA is an important initial screening in the diagnosis of ACC of salivary gland. Increased study of the cytomorphology of ACC is beneficial for more accurate diagnosis of ACC, to reduce misdiagnosis and oversight.

Primary minor salivary gland tumors: A retrospective review of cases seen in a tertiary institution in South East Nigeria

Background

Tumors of the minor salivary glands (MSGs) are rare. They constitute a wide range of histologic types despite their low frequency.

Aim

The aim of this study is to evaluate the clinical and pathological features of 11 different tumors of MSGs presented at the University of Nigeria Teaching Hospital Ituku-Ozalla, Enugu and to compare them with similar studies done elsewhere.

Patients and Method

This is a retrospective study of patients with tumors involving the MSGs seen at the OMFS and ORL clinics, UNTH. Information regarding demographic characteristics, duration at first presentation, types of tumors, site and side affected, and treatment given were recorded in patients' medical records. Data were analyzed using SPSS version 23; qualitative variables were compared using Chi-square test.

Result

One hundred and thirty three cases of various lesions involving the salivary gland were seen within the study period. Fifty three (39.8%) patients met the inclusion criteria and are reported further. Twenty eight (28) cases occurred in males. The mean age of the patients was 39.8 years STD 16.5, while the mean duration of the swellings at presentation was 45.5 months STD 35.4. Pleomorphic adenoma was the most common of the 29 (54.7%) benign histopathologic type seen. The soft palate was the commonest site affected 37 (69.8%). Local excision with wide margin was adequate in treating majority of the swellings 40 (75.5%), while 1 (1.9%) case of recurrence was seen within the study period.

Conclusion

Tumors involving the MSGs are uncommon; males are mostly affected in our environment.

Pentapartite fractionation of particles in oral fluids by differential centrifugation

Oral fluids (OFs) contain small extracellular vesicles (sEVs or exosomes) that carry disease-associated diagnostic molecules. However, cells generate extracellular vesicles (EVs) other than sEVs, so the EV population is quite heterogeneous. Furthermore, molecules not packaged in EVs can also serve as diagnostic markers. For these reasons, developing a complete picture of particulate matter in the oral cavity is important before focusing on specific subtypes of EVs. Here, we used differential centrifugation to fractionate human OFs from healthy volunteers and patients with oral squamous cell carcinoma into 5 fractions, and we characterized the particles, nucleic acids, and proteins in each fraction. Canonical exosome markers, including CD63, CD9, CD133, and HSP70, were found in all fractions, whereas CD81 and AQP5 were enriched in the 160K fraction, with non-negligible amounts in the 2K fraction. The 2K fraction also contained its characteristic markers that included short derivatives of EGFR and E-cadherin, as well as an autophagosome marker, LC3, and large multi-layered vesicles were observed by electronic microscopy. Most of the DNA and RNA was recovered from the 0.3K and 2K fractions, with some in the 160K fraction. These results can provide guideline information for development of purpose-designed OF-based diagnostic systems.

Role of nuclear morphometry in diagnosis of salivary gland neoplasms

BACKGROUND

Fine needle aspiration cytology is an important diagnostic tool in salivary gland cytopathology. However, cytology of salivary gland neoplasms shows diversity with morphological overlap, heterogeneity and subjective variability, posing diagnostic challenge. Nuclear cytomorphometric image analysis turns the subjective criteria into quantitative parameters, which may aid not only in differentiating between benign and malignant tumours but also can aid in categorising challenging cases with morphological overlap.

METHODS

A retrospective analysis of Papanicolaou stained fine needle aspirate smears from 50 patients with salivary gland neoplasms, with available follow-up histopathology, was performed. The aspirates were categorised in to three neoplastic categories of Milan system for reporting salivary gland cytology (MSRSGC) that is benign neoplasm, salivary gland neoplasm with uncertain malignant potential, and malignant. The smears were subjected to cytomorphometric image analysis using Image Pro Software (version 10). Each nucleus was analysed for 13 parameters including aspect ratio, intensity, diameter, perimeter, roundness, area, Feret diameter, circularity, radii, Fournier description and chromatin texture characteristics such as margination, heterogeneity and clumpiness. The data obtained was compared through relevant statistical methods.

RESULTS

The comparative morphometric data obtained for parameters using ANOVA, for the three categories showed statistically significant P values (<0.001). The post hoc test (Games-Howel) test also showed significant P values (<.001).

CONCLUSION

Cytomorphometric image analysis is an important tool in diagnosis of salivary gland neoplasms and can improve the diagnostic accuracy for better treatment and improved prognosis. However, more studies with larger sample size may be needed in future for further affirming its role.

Adenoid cystic carcinoma of the sublingual gland: A case report

Adenoid cystic carcinoma (ACC) of the sublingual gland is an extremely rare neoplasm. The clinicopathological characteristics of ACC are slow-growing swelling with or without ulceration, perineural spread, local recurrence, and distant metastasis. This report describes a 58-year-old male who had a slowly growing swelling without ulceration on the right side of the mouth floor that had been present for 1 month. In a radiological examination, the mass showed multilocular cystic features and no bony or tongue muscle invasion. No enlarged cervical lymph nodes were detected. Excisional biopsy and histological analysis showed that the lesion was ACC. In addition to reporting a rare case of ACC, this report also discusses the differential diagnosis and treatment of ACC with a review of the relevant literature.