Multispectral optoacoustic tomography of benign parotid tumors in vivo: a prospective observational pilot study.

Parotid lumps are a heterogeneous group of mainly benign but also malignant tumors. Preoperative imaging does not allow a differentiation between tumor types. Multispectral optoacoustic tomography (MSOT) may improve the preoperative diagnostics. In this first prospective pilot trial the ability of MSOT to discriminate between the two most frequent benign parotid tumors, pleomorphic adenoma (PA) and Warthin tumor (WT) as well as to normal parotid tissue was explored. Six wavelengths (700, 730, 760, 800, 850, 900 nm) and the parameters deoxygenated (HbR), oxygenated (HbO2), total hemoglobin (HbT), and saturation of hemoglobin (sO2) were analyzed. Ten patients with PA and fourteen with WT were included (12/12 female/male; median age: 51 years). For PA, the mean values for all measured wave lengths as well as for the hemoglobin parameters were different for the tumors compared to the healthy parotid (all p < 0.05). The mean MSOT parameters were all significantly higher (all p < 0.05) in the WT compared to healthy parotid gland except for HbT and sO2. Comparing both tumors directly, the mean values of MSOT parameters were not different between PA and WT (all p > 0.05). Differences were seen for the maximal MSOT parameters. The maximal tumor values for 900 nm, HbR, HbT, and sO2 were lower in PA than in WT (all p < 0.05). This preliminary MSOT parotid tumor imaging study showed clear differences for PA or WT compared to healthy parotid tissue. Some MSOT characteristics of PA and WT were different but needed to be explored in larger studies.

Case of eccrine chondroid syringoma of the upper lip.

Chondroid syringoma (CS) is a benign, slow-growing mixed tumour that arises from the sweat glands and usually presents in the head and neck area. Histopathological examination is important for proper diagnosis, as CS is often confused with epidermal cysts due to its rare presentation. This article presents a man in his 40s with a right upper lip mass that emerged 6 months prior to presentation. An intraoral surgical excision was performed and the histopathological analysis revealed solid epithelial cells that formed multiple, non-branching ducts lined by cuboidal epithelium. Cystic spaces were filled by heterogeneous eosinophilic material embedded in chondromyxoid stroma. Histopathology identified the lesion as an eccrine-variant CS. The patient recovered well.

Characterization of parotid gland tumors using diffusion-relaxation correlation spectrum imaging: a preliminary study.

AIM: To assess the performance of diffusion-relaxation correlation spectrum imaging (DR-CSI) in the characterization of parotid gland tumors. MATERIALS AND METHODS: Twenty-five pleomorphic adenomas (PA) patients, 9 Warthin's tumors (WT) patients and 7 malignant tumors (MT) patients were prospectively recruited. DR-CSI (7 b-values combined with 5 TEs, totally 35 diffusion-weighted images) was scanned for pre-treatment assessment. Diffusion (D)-T2 signal spectrum summating all voxels were built for each patient, characterized by D-axis with range 0∼5 × 10-3 mm2/s, and T2-axis with range 0∼300ms. With boundaries of 0.5 and 2.5 × 10-3 mm2/s for D, all spectra were divided into three compartments labeled A (low D), B (mediate D) and C (high D). Volume fractions acquired from each compartment (VA, VB, VC) were compared among PA, WT and MT. Diagnostic performance was assessed using receiver operating characteristic analysis and area under the curve (AUC). RESULTS: Each subtype of parotid tumors had their specific D-T2 spectrum. PA showed significantly lower VA (8.85 ± 4.77% vs 20.68 ± 10.85%), higher VB (63.40 ± 8.18% vs 43.05 ± 7.16%), and lower VC (27.75 ± 8.51% vs 36.27 ± 11.09) than WT (all p<0.05). VB showed optimal diagnostic performance (AUC 0.969, sensitivity 92.00%, specificity 100.00%). MT showed significantly higher VA (21.23 ± 12.36%), lower VB (37.09 ± 6.43%), and higher VC (41.68 ± 13.72%) than PA (all p<0.05). Similarly, VB showed optimal diagnostic performance (AUC 0.994, sensitivity 96.00%, specificity 100.00%). No significant difference of VA, VB and VC was found between WT and MT. CONCLUSIONS: DR-CSI might be a promising and non-invasive way for characterizing parotid gland tumors.

An ultrasound-based histogram analysis model for prediction of tumour stroma ratio in pleomorphic adenoma of the salivary gland.

OBJECTIVES: Preoperative identification of different stromal subtypes of pleomorphic adenoma (PA) of the salivary gland is crucial for making treatment decisions. We aimed to develop and validate a model based on histogram analysis (HA) of ultrasound (US) images for predicting tumour stroma ratio (TSR) in salivary gland PA. METHODS: A total of 219 PA patients were divided into low-TSR (stroma-low) and high-TSR (stroma-high) groups and enrolled in a training cohort (n = 151) and a validation cohort (n = 68). The least absolute shrinkage and selection operator regression algorithm was used to screen the most optimal clinical, US, and HA features. The selected features were entered into multivariable logistic regression analyses for further selection of independent predictors. Different models, including the nomogram model, the clinic-US (Clin + US) model, and the HA model, were built based on independent predictors using logistic regression. The performance levels of the models were evaluated and validated on the training and validation cohorts. RESULTS: Lesion size, shape, cystic areas, vascularity, HA_mean, and HA_skewness were identified as independent predictors for constructing the nomogram model. The nomogram model incorporating the clinical, US, and HA features achieved areas under the curve of 0.839 and 0.852 in the training and validation cohorts, respectively, demonstrating good predictive performance and calibration. Decision curve analysis and clinical impact curves further confirmed its clinical usefulness. CONCLUSIONS: The nomogram model we developed offers a practical tool for preoperative TSR prediction in PA, potentially enhancing clinical decision-making.

Correlation between MRI (DWI and DCE) and cellularity of parotid gland pleomorphic adenomas.

PURPOSE: Parotid pleomorphic adenomas present a risk of recurrence, higher when the tumour is a hypocellular subtype. The aim of the study was to determine whether it is possible to characterize this histological subtype with diffusion and perfusion sequences of the preoperative MRI. METHODS: This retrospective study included 97 patients operated between 2010 and 2020. Histologic slides review was performed to classify tumours into three histologic subtypes: hypocellular, classical and hypercellular. Univariate and multivariate analyses studied the correlation between histology and diffusion and perfusion MRI parameters obtained with OleaSphere® software. RESULTS: The hypocellular subtype had higher apparent diffusion coefficient values than the other two subtypes: 2.13 ± 0.23, 1.83 ± 0.42, and 1.61 ± 0.4 × 10-3 mm2/s for hypocellular, classical and hypercellular subtype respectively (p < 0.0001). Multivariate analysis showed that an ADCmean > 1.88 × 10-3 mm2/s was suggestive of a hypocellular pleomorphic adenoma in 79% of the cases, with a specificity and PPV of 94 and 96% (p < 0.001), respectively. CONCLUSION: The histological subtype of a pleomorphic adenoma can be predicted preoperatively with ADC values. A prospective and multicentric study on a larger cohort is needed to confirm our results.

Submandibular gland carcinoma ex pleomorphic adenoma with calcification.

We report an unusual case of carcinoma ex pleomorphic adenoma (CXPA) in the submandibular gland. The mass had a unique calcification. Panoramic tomography revealed sponge-like calcification. The central portion displayed heterogeneous high signal intensity on T1-weighted image (T1WI) and T2-weighted image (T2WI), and heterogeneously moderate signal intensity on a short-TI inversion recovery (STIR) image. The ADC was low (0.78 × 10-3mm2/sec). After surgical excision, a pathological examination revealed that the mass contained CXPA as a minor component. Tumor cells with large hyperchromatic nuclei and eosinophilic or clear cytoplasm proliferated in irregular small tubule formations or cribriform or Roman-bridge structures in hyalinized or focally ossified stroma. The entire mass was calcified, particularly in the central region. Taken together, the reduced T1 relaxation times were related to the surface effects of diamagnetic particles, which were observed at calcium particle concentrations of up to 30%. We report a CXPA with unusual sponge-like calcification, which appeared unusually hyperintense on T1WI due to a surface effect.

INFLUENCE OF THE PATIENT'S SEX AND AGE, VOLUMES OF THE SALIVARY GLAND AND PLEOMORPHIC ADENOMA ON THE TUMOR HISTOLOGICAL VARIANTS.

OBJECTIVE: Aim: The purpose of the study was to identify the influence of the patient's sex and age, the volumes of the salivary gland and pleomorphic adenoma on the histological variants of the tumor. PATIENTS AND METHODS: Materials and Methods: The study included 21 women and 9 men with pleomorphic adenomas of the salivary gland. In 15 cases, a mesenchymal variant of pleomorphic adenoma was identified, in 5 cases - an epithelial variant, in 10 cases - a mixed variant. The average age of the patients was 39.7±2.9 years. Patients with pleomorphic adenomas underwent magnetic resonance imaging using a Siemens MAGNETOM Aera 1.5T device (Germany), during which three projections of the tumor and salivary gland were measured (antero-posterior, lateral, vertical) with subsequent calculation of their volumes, and then the ratios of these volumes. Classification trees were used to determine whether patients belonged to one of three variants of pleomorphic adenoma. The CART (Classification And Regression Tree) algorithm was used as a branching option. Stopping branching was carried out using the FACT (Fact-style direct stopping) method until each terminal (final) node of the tree does not contain incorrectly classified observations or when their number becomes less than a given proportion of the total group size (less than 5%). Determination of the structure and relationships between the tumor variants and such indicators as gender, age and radiological indicators (volume of the tumor, volume of the salivary gland, ratio of tumor volume to salivary gland volume) was carried out using correspondence analysis. RESULTS: Results: Epithelial variant of pleomorphic adenoma is more typical for women, and the mixed and mesenchymal variant is more common for patients of both sexes. The epithelial variant can develop in patients of any age, while the mixed variant occurs mainly in patients older than 41 years, and the mesenchymal variant - mainly in patients younger than 41 years. The ratio of the volume of the tumor to the volume of the salivary gland will be predominantly >0.17 in the epithelial variant of pleomorphic adenoma, predominantly ≤0.17 in the mesenchymal variant, and can take any value in the mixed variant. CONCLUSION: Conclusions: The authors conducted a study in order to identify the influence of sex, age of the patient, and the ratio of the volume of pleomorphic adenoma to the volume of the salivary gland on the histological variant of the tumor. The revealed data will be useful in the treatment and diagnostic process in patients with pleomorphic adenoma of the salivary gland.

[Imaging findings of carcinoma ex pleomorphic adenoma in minor salivary glands].

PURPOSE: To summarize the CT and MR imaging features of carcinoma ex pleomorphic adenoma(Ca-ex-PA) in minor salivary gland, and analyze the correlation between various features and pathological classification. METHODS: Forty-three patients with Ca-ex-PA in minor salivary gland were collected. The CT and MRI findings were retrospectively analyzed and correlated with their pathological types. Fisher's exact test was used to analyze the correlation between various imaging features (tumor morphology, boundary, internal structure, bone invasion, cervical lymph node metastasis) and pathological types with SPSS 25.0 software package. RESULTS: Among the 43 patients with Ca-ex-PA, 83.7%(36/43) of the tumors were lobulated; 81.4%(35/43) showed cystic degeneration or necrosis, with heterogeneous enhancement. Coarse calcification or mixed calcification was found in 37.2%(16/43), 25.6%(11/43) had compressive absorption of adjacent bone. 75%(12/16) of type Ⅰ/Ⅱ tumors had regular morphology (round or oval), and 77.8%(21/27) of type Ⅲ tumors had irregular morphology, 93.8%(15/16) of type Ⅰ/Ⅱ tumors had well-defined margin and 66.7%(18/27) of type Ⅲ tumors had ill-defined margin. Osteolytic bone resorption occurred in 59.3%(16/27) of type Ⅲ tumors. The average maximum diameter of type Ⅰ/Ⅱ tumors was significantly shorter than that of type Ⅲ(P＜0.05). Fisher's exact test showed the characteristics of tumor morphology, boundary and osteolytic bone resorption were related to pathological grouping(P＜0.001). CONCLUSIONS: Most Ca-ex-PA in minor salivary glands is characterized by lobular and heterogeneous enhanced neoplasm on CT and MR imaging. A round or oval tumor with well-defined margin usually correlates with typeⅠ and Ⅱ, contrarily, an irregular mass with ill-defined margin and osteolytic bone destruction usually correlates with type Ⅲ. Combining the three characteristics of morphology, boundary and osteolysis is more helpful to distinguish type Ⅰ/Ⅱ and type Ⅲ tumors.

Enhanced CT combined with texture analysis for differential diagnosis of pleomorphic adenoma and adenolymphoma.

OBJECTIVE: This study sought to evaluate the worth of the general characteristics of enhanced CT images and the histogram parameters of each stage in distinguishing pleomorphic adenoma (PA) and adenolymphoma (AL). METHODS: The imaging features and histogram parameters of preoperative enhanced CT images in 20 patients with PA and 29 patients with AL were analyzed. Tumor morphology and histogram parameters of PA and AL were compared. Area under the curve (AUC), sensitivity, and subject operational feature specificity (ROC) analysis were used to determine the differential diagnostic effect of single-stage or multi-stage parameter combinations. RESULTS: The difference in CT value and net enhancement value of arterial phase (AP) were significant (p < 0.05); Flat sweep phase (FSP), AP mean, percentiles, 10th, 50th, 90th, 99th and arterial period variance and venous phase (VP) kurtosis in the nine histogram parameters of each period (p < 0.05). An analysis of the ROC curve revealed a maximum area beneath the curve (AUC) in the 90th percentile of FSP for a single-parameter differential diagnosis to be 0.870. The diagnostic efficacy of the mean value of FSP + The 90th percentile of AP + Kurtosis of VP was the best in multi-parameter combination diagnosis, with an AUC of 0.925, and the sensitivity and specificity of 0.900 and 0.850, respectively. CONCLUSION: The histogram analysis of enhanced CT images is valuable for the differentiation of PA and AL. Moreover, the combination of single-stage parameters or multi-stage parameters can improve the differential diagnosis efficiency.

Differentiation between pleomorphic adenoma and schwannoma in the parapharyngeal space: histogram analysis of apparent diffusion coefficient.

OBJECTIVES: To elucidate the differences between pleomorphic adenomas and schwannomas occurring in the parapharyngeal space by histogram analyses of apparent diffusion coefficient (ADC) values measured with diffusion-weighted MRI. METHODS: This retrospective study included 29 patients with pleomorphic adenoma and 22 patients with schwannoma arising in the parapharyngeal space or extending into the parapharyngeal space from the parotid region. Using pre-operative MR images, ADC values of tumor lesions showing the maximum diameter were measured. The regions of interest for ADC measurement were placed by contouring the tumor margin, and the histogram metrics of ADC values were compared between pleomorphic adenomas and schwannomas regarding the mean, skewness, and kurtosis by Wilcoxon's rank sum test. Subsequent to the primary analysis which included all lesions, we performed two subgroup analyses regarding b-values and magnetic field strength used for MRI. RESULTS: The mean ADC values did not show significant differences between pleomorphic adenomas and schwannomas for the primary and subgroup analyses. Schwannomas showed higher skewness (p = 0.0001) and lower kurtosis (p = 0.003) of ADC histograms compared with pleomorphic adenomas in the primary analysis. Skewness was significantly higher in schwannomas in all the subgroup analyses. Kurtosis was consistently lower in schwannomas but did not reach statistical significance in one subgroup analysis. CONCLUSIONS: Skewness and kurtosis showed significant differences between pleomorphic adenomas and schwannomas occupying the parapharyngeal space, but the mean ADC values did not. Our results suggest that the skewness and kurtosis of ADC histograms may be useful in differentiating these two parapharyngeal tumors.

Differentiation of neurogenic tumours and pleomorphic adenomas in the parapharyngeal space based on texture analysis of T2WI.

BACKGROUND: The purpose of this study was to identify neurogenic tumours and pleomorphic adenomas of the parapharyngeal space based on the texture characteristics of MRI-T2WI. METHODS: MR findings and pathological reports of 25 patients with benign tumours in the parapharyngeal space were reviewed retrospectively (13 cases with pleomorphic adenomas and 12 cases with neurogenic tumours). Using PyRadiomics, the texture of the region of interest in T2WI sketched by radiologists was analysed. By using independent sample t-tests and Mann‒Whitney U tests, the selected texture features of 36 Gray Level Co-Occurrence Matrix (GLCM) and Gray Level Dependence Matrix (GLDM) were tested. A set of parameters of texture features showed statistically significant differences between the two groups, which were selected, and the diagnostic efficiency was evaluated via the operating characteristic curve of the subjects. RESULTS: The differences in the three parameters - small dependence low level emphasis (SDLGLE), low level emphasis (LGLE) and difference variance (DV) of characteristics - between the two groups were statistically significant (P < 0.05). No significant difference was found in the other indices. ROC curves were drawn for the three parameters, with AUCs of 0.833, 0.795, and 0.744, respectively. CONCLUSIONS: There is a difference in the texture characteristic parameters based on magnetic resonance T2WI images between neurogenic tumours and pleomorphic adenomas in the parapharyngeal space. For the differential diagnosis of these two kinds of tumours, texture analysis of significant importance is an objective and quantitative analytical tool.

A nomogram incorporating clinical, conventional ultrasound and shear wave elastography findings for distinguishing pleomorphic adenoma from Warthin's tumor of the major salivary glands.

OBJECTIVE: Pre-operative differentiation between pleomorphic adenoma (PA) and Warthin's tumor (WT) of the major salivary glands is crucial for treatment decisions. The purpose of this study was to develop and validate a nomogram incorporating clinical, conventional ultrasound (CUS) and shear wave elastography (SWE) features to differentiate PA from WT. METHODS: A total of 113 patients with histological diagnosis of PA or WT of the major salivary glands treated at Fujian Medical University Union Hospital were enrolled in training cohort (n = 75; PA = 41, WT = 34) and validation cohort (n = 38; PA = 22, WT = 16). The least absolute shrinkage and selection operator (LASSO) regression algorithm was used for screening the most optimal clinical, CUS, and SWE features. Different models, including the nomogram model, clinic-CUS (Clin+CUS) and SWE model, were built using logistic regression. The performance levels of the models were evaluated and validated on the training and validation cohorts, and then compared among the three models. RESULTS: The nomogram incorporating the clinical, CUS and SWE features showed favorable predictive value for differentiating PA from WT, with the area under the curves (AUCs) of 0.947 and 0.903 for the training cohort and validation cohort, respectively. Decision curve analysis showed that the nomogram model outperformed the Clin+CUS model and SWE model in terms of clinical usefulness. CONCLUSIONS: The nomogram had good performance in distinguishing major salivary PA from WT and held potential for optimizing the clinical decision-making process.

Atypical Chondroid Syringoma of the Toe.

Although chondroid syringoma rarely occurs outside the head and neck, the majority of malignant chondroid syringomas are identified in the extremities. Here, we present a case of atypical chondroid syringoma in the fifth toe. Diagnosis of chondroid syringoma with atypical cells was made following initial excisional biopsy and histology, necessitating repeated surgery for positive margins. In this case report, we examine the radiopathologic correlation of this diagnosis, detail the imaging findings of benign and malignant chondroid syringomas, and highlight how magnetic resonance imaging can be used to guide surgical planning and treatment course of this potentially malignant tumor.

Keloid masking a parotid tumor: A rare case presentation.

A 37-year-old Nigerian woman presented with an itchy and occasionally painful scar that appeared after the healing of an acne lesion over the left parotid region, 13 years ago. She noticed a progressive increase; however, there was no history of facial weakness. Examination revealed a keloid lesion overlying a firm nontender mass. Ultrasound scan and fine-needle aspiration cytology indicated a benign tumor of the left parotid. Superficial parotidectomy was performed, and the histology revealed a keloid overlying a pleomorphic adenoma. This is an unusual presentation of keloid which developed over a pleomorphic adenoma. Hence, we report the above case for its rarity.

Résumé Une femme Nigériane de 37 ans s'est présentée avec une cicatrice qui démangeait et parfois était douloureuse, apparue après la cicatrisation d'une lésion acnéique sur le région parotide gauche, il y a 13 ans. Elle a remarqué une augmentation progressive; cependant, il n'y avait aucun antécédent de faiblesse faciale. Examen révélé une lésion chéloïde recouvrant une masse ferme non sensible. L'échographie et la cytoponction à l'aiguille fine ont révélé une tumeur bénigne du côté gauche parotide. Une parotidectomie superficielle a été réalisée et l'histologie a révélé une chéloïde recouvrant un adénome pléomorphe. C'est un peu inhabituel présentation d'une chéloïde qui s'est développée sur un adénome pléomorphe. Par conséquent, nous signalons le cas ci-dessus pour sa rareté. Mots-clés: Cicatrice chéloïde, adénome pléomorphe, rare.

Synchronous pleomorphic adenoma in parotid gland and parapharyngeal space: a case report and literature review.

Synchronous pleomorphic adenoma in the parotid gland and parapharyngeal space are rare. We report a case of simultaneous pleomorphic adenoma in parotid gland and parapharyngeal space in a 65-year-old male presenting to the ENT outpatient department at Northwest General Hospital, Peshawar. The patient presented with a left parotid lump, intra oral examination of which revealed the left palatine tonsil to have been pushed medially. CT of the neck showed a completely separate lump in the left parapharyngeal space, and FNAC of the parotid lump was suggestive of mucoepidermoid carcinoma. The superficial parotid lump was excised first, and the parapharyngeal growth was accessed intraorally and excised. Histopathology revealed both the growths to be pleomorphic adenomas. It is important to raise awareness of synchronous salivary gland tumours, which are a rare occurrence, to highlight its optimal investigation to ensure complete surgical excision, and appropriate management.

Concurrent FDG-Avid and Non-FDG-Avid Pleomorphic Adenomas in the Submandibular Gland and Parapharyngeal Space.

ABSTRACT: Pleomorphic adenoma is the most common benign tumor of salivary glands. Here we present an interesting case of concurrent pleomorphic adenomas in the parapharyngeal space and submandibular gland. The tumors showed stark differences in the imaging findings on FDG PET/CT and MRI. Pathology confirmed the diagnosis of pleomorphic adenomas with the different composition of the cellular component and chondromyxoid stroma. This case suggests that the difference in cellularity of pleomorphic adenomas can affect FDG uptake and diffusion-weighted MRI-derived apparent diffusion coefficient values.