Normal Parotid Gland Research Articles

Sonographic biometry of apparently normal parotid gland among adults in Asaba, South-South Nigeria

Background: Detecting subtle changes in the parotid gland size can be difficult when there are no established reference values in a specific area. This can affect patient management and delay early detection of diseases. Therefore, the objective of this study was to describe the size of the parotid gland of adult Nigerian people.Methods: This cross-sectional study included apparently healthy adults. The parotid glands were scanned in various sections using a 7.5 MHz probe after applying ultrasound gel. Each dimension was measured twice, and the mean value was calculat-ed. The 95% reference rages (mean ± 1.96 standard deviation) were described for various dimensions of the parotid glands.Results: Four hundred healthy adults participated in the survey. Their mean (standard deviation) age was 38.6 (14.6) years. The mean (95% reference range) of both parotid lengths was 4.7 (4.1 – 5.3) cm. The right and left parotid transverse sizes were 3.8 (3.4 – 4.2) and 3.7 (2.9 – 4.5) respectively. The right and left parotid depths lateral to the mandible were 0.8 (0.4 – 1.2) and 0.9 (0.3 – 1.5), parotid depths dorsal to the mandible were 2.3 (1.7 – 2.9) and 2.2 (1.8 – 2.6), and parotid volume were 20.3 (13.3 – 27.1) and 19.8 (14.3 – 25.3) cm3. No significant difference was seen between the right and left parotid glands in men and women.Conclusion: This study delineates the mean and reference range values of parotid glands among healthy adults of Nigeria which can be used for clinical decision making.

Deep learning for the automatic detection and segmentation of parotid gland tumors on MRI

ObjectivesParotid gland tumors (PGTs) often occur as incidental findings on magnetic resonance images (MRI) that may be overlooked. This study aimed to construct and validate a deep learning model to automatically identify parotid glands (PGs) with a PGT from normal PGs, and in those with a PGT to segment the tumor. Materials and methodsThe nnUNet combined with a PG-specific post-processing procedure was used to develop the deep learning model trained on T1-weighed images (T1WI) in 311 patients (180 PGs with tumors and 442 normal PGs) and fat-suppressed (FS)-T2WI in 257 patients (125 PGs with tumors and 389 normal PGs), for detecting and segmenting PGTs with five-fold cross-validation. Additional validation set separated by time, comprising T1WI in 34 and FS-T2WI in 41 patients, was used to validate the model performance. Results and conclusionTo identify PGs with tumors from normal PGs, using combined T1WI and FS-T2WI, the deep learning model achieved an accuracy, sensitivity and specificity of 98.2% (497/506), 100% (119/119) and 97.7% (378/387), respectively, in the cross-validation set and 98.5% (67/68), 100% (20/20) and 97.9% (47/48), respectively, in the validation set. For patients with PGTs, automatic segmentation of PGTs on T1WI and FS-T2WI achieved mean dice coefficients of 86.1% and 84.2%, respectively, in the cross-validation set, and of 85.9% and 81.0%, respectively, in the validation set. The proposed deep learning model may assist the detection and segmentation of PGTs and, by acting as a second pair of eyes, ensure that incidentally detected PGTs on MRI are not missed.

Differentiation of parotid pleomorphic adenoma from Warthin tumor using signal intensity ratios on fat-suppressed T2-weighted magnetic resonance imaging

ObjectiveTo investigate the value of magnetic resonance imaging (MRI) signal intensity ratios (SIRs) based on fat-suppressed T2-weighted imaging (FS-T2WI), together with demographic features, MRI anatomical characteristics, and SIRs of histopathological patterns of the tumors, in the differentiation of parotid pleomorphic adenoma (PA) from Warthin tumor (WT). Study DesignIn total, 90 patients with PA and 56 patients with WT were enrolled in the study. SIRs of tumor to normal parotid gland (SIR-T/P), spinal cord (SIR-T/S), and muscle (SIR-T/M) were calculated. Demographic and MRI anatomical features of the two patient groups were compared with univariate analysis and multivariate logistic regression analysis. The area under the receiver operating characteristic curve (AUC), sensitivity, and specificity were analyzed to evaluate the utility of SIRs in distinguishing between PA and WT. ResultsSIR-T/P exhibited outstanding discriminating ability (AUC=0.934), SIR-T/S had excellent discrimination (AUC=0.839), and SIR-T/M showed acceptable discrimination (AUC=0.728). When SIR-T/P of 1.96 was selected as the cutoff value, sensitivity and specificity were 0.756 and 0.982, respectively. SIR-T/P, age, sex, and number of lesions were identified as independent predictors by multivariate logistic regression analysis. Differences in SIRs between histopathological patterns were significant. ConclusionSIR-T/P based on FS-T2WI is an effective discriminator in the differential diagnosis between PA and WT. Age, sex, and number of lesions provided additional value in the differentiation.

Single-cell transcriptomic analysis uncovers the origin and intratumoral heterogeneity of parotid pleomorphic adenoma

Pleomorphic adenoma (PA) is the most common benign tumour in the salivary gland and has high morphological complexity. However, the origin and intratumoral heterogeneity of PA are largely unknown. Here, we constructed a comprehensive atlas of PA at single-cell resolution and showed that PA exhibited five tumour subpopulations, three recapitulating the epithelial states of the normal parotid gland, and two PA-specific epithelial cell (PASE) populations unique to tumours. Then, six subgroups of PASE cells were identified, which varied in epithelium, bone, immune, metabolism, stemness and cell cycle signatures. Moreover, we revealed that CD36+ myoepithelial cells were the tumour-initiating cells (TICs) in PA, and were dominated by the PI3K-AKT pathway. Targeting the PI3K-AKT pathway significantly inhibited CD36+ myoepithelial cell-derived tumour spheres and the growth of PA organoids. Our results provide new insights into the diversity and origin of PA, offering an important clinical implication for targeting the PI3K-AKT signalling pathway in PA treatment.

An Uncommon Salivary Gland Swelling- Parotid Duct Cyst and Its Management.

Cysts in the parotid region are more common in the gland than in the duct. Isolated cyst of parotid duct is a rare presentation. The treatment for most of the cystic lesions of the parotid or the parotid duct is the excision of the cyst with superficial parotidectomy. However, these lesions can be approached intra-orally for marsupialization achieving the same surgical results with less morbidity. This paper presents a rare case of parotid duct cyst which was managed by intraoral drainage and marsupialization. A 53-year-old female presented with swelling in the right cheek, associated with frequent fluid drainage inside the oral cavity for four months. Radiology and Fine needle aspiration revealed a benign parotid duct cyst with normal parotid gland. It was managed by a simple surgical technique of marsupialization. The patient was followed up for 1 year with no evidence of recurrence. Marsupialization obviates the need for parotidectomy in the simple cystic lesion of the parotid duct, unlike the cystic lesion in the gland per se and also reduces risk of recurrence. The simplicity and lack of major complications make it an effective treatment for salivary duct cysts.

A rare case of nodular fasciitis presenting as a parotid tumor: Clues to cytodiagnosis

A 14-year-old boy presented with left preauricular painless swelling of 10 months’ duration. Local examination revealed a 3 × 2-cm, firm, nodular, nonmobile mass in the left preauricular area, just in front of tragus. Fine needle aspiration yielded paucicellular smears comprising singly scattered histiocyte/myofibroblast-like spindle cells and occasional giant cells. It was reported as benign mesenchymal lesion on cytology. Left superficial parotidectomy was performed. Histopathological and immunohistochemical analysis confirmed the diagnosis of nodular fasciitis (NF). It was an illcircumscribed cellular neoplasm, abutting and focally infiltrating into otherwise normal parotid gland. The tumor comprised spindle cells arranged in short bundles and storiform pattern with interspersed osteoclast-like giant cells, foam cells, extravasated red blood cells (RBCs), and focal areas of keloidal collagenization. The cells were positive for smooth muscle actin and negative for CD34, beta-catenin, S100, and pancytokeratin. Final diagnosis of NF was rendered. NF can rarely involve the parotid gland or present as parotid enlargement and pose diagnostic challenge, especially on cytology. However, in appropriate clinical context, subtle cytomorphological clues such as presence of myofibroblasts and fibrocollagenous stromal fragments can help in ruling out the commonly occurring salivary gland neoplasms and offering a definitive cytodiagnosis of NF which will be helpful in deciding the further course of management.

Proliferative Activity of Myoepithelial Cells in Normal and Diabetic Parotid Glands Based on Double Immunostaining Labeling

AIM: This study aimed to examine the effect of diabetes mellitus on the histology of parotid glands and to give a scientific overview of the distribution and the proliferative activity of myoepithelial cells (MECs) encircling both ducts and acini in parotid gland of both normal and diabetic mongrel dogs. MATERIALS AND METHODS: Twelve male mongrel dogs were used in the experiment and divided into two equal groups, group I, control group, group II, dogs with alloxan-induced diabetes. The dogs of the group II were injected by fresh preparation of a single dose of 100 mg/kg body weight of alloxan monohydrate dissolved in physiological saline. Ten days later, blood glucose level was determined using enzymatic colorimetric test; dogs presented a glucose level at or above 200 mg/dL were included in the diabetic group of the experiment. Three months later, dogs were sacrificed and the parotid glands from all groups were dissected and prepared for histological examination and double immunohistochemical expression of both actin and proliferating cell nuclear antigen (PCNA). RESULTS: Histological findings using H and E staining confirmed that the parotid gland parenchyma of the diabetic group had glandular atrophy characterized by loss of normal gland structure, acinar degeneration, and dilatation of the duct system with the presence of duct like structure. Moreover, there was a predominance of the fibrous component with the presence of fat cells within the gland compartments. Immunohistochemical findings of parotid gland of control group revealed positive scattered actin staining of weak to mild quantity in cells embracing some acini and intralobular ducts. Expression of PCNA in actin-positive cells revealed few scattered reactions embracing some acini and small ducts. Parotid gland of diabetic dogs revealed positive actin staining of mild-to-moderate quantity in the cells encircling the acini, intralobular, and some interlobular ducts. Expression of PCNA in actin- positive cells revealed mild-to-moderate positive reaction more concentrated in the cells surrounding both acini and intercalated ducts. CONCLUSION: Routine histological findings of diabetic dogs in our findings showed abundant pathological changes in parenchymal tissue elements, including acinar, ductal, and MECs that had a significant impact on saliva production and secretion resulting in dry mouth. The proliferative activity of MECs in the control group indicated a routine regeneration process, whereas the abundant proliferative activity in the diabetic group might indicate pathological transformation rather than regeneration, especially because no remedial measures were taken during this investigation.

Impact of physiological parameters on the parotid gland fat fraction in a normal population

Quantifying physiological fat tissue in the organs is important to further assess the organ’s pathologic status. This study aimed to investigate the impact of body mass index (BMI), age, and sex on the fat fraction of normal parotid glands. Patients undergoing magnetic resonance imaging (MRI) of iterative decomposition of water and fat with echo asymmetry and least squares estimation (IDEAL-IQ) due to non-salivary gland-related disease were reviewed. Clinical information of individual patients was categorized into groups based on BMI (under/normal/overweight), age (age I/age II/age III), and sex (female/male) and an inter-group comparison of the fat fraction values of both parotid glands was conducted. Overall, in the 626 parotid glands analyzed, the fat fraction of the gland was 35.80%. The mean fat fraction value increased with BMI (30.23%, 35.74%, and 46.61% in the underweight, normal and overweight groups, respectively [p < 0.01]) and age (32.42%, 36.20%, and 41.94% in the age I, II, and III groups, respectively [p < 0.01]). The fat content of normal parotid glands varies significantly depending on the body mass and age regardless of sex. Therefore, the patient’s age and body mass should be considered when evaluating fatty change in the parotid glands in imaging results.

Eligibility for 177Lu-PSMA Therapy Depends on the Choice of Companion Diagnostic Tracer: A Comparison of 68Ga-PSMA-11 and 99mTc-MIP-1404 in Metastatic Castration-Resistant Prostate Cancer.

177Lu-prostate-specific membrane antigen-617 (177Lu-PSMA-617) is an effective therapy for metastatic castration-resistant prostate cancer (mCRPC), with evidence of improved survival over standard care. The VISION trial inclusion criteria required a metastatic lesion-to-liver ratio of greater than 1 on 68Ga-PSMA-11 PET scans. We aimed to determine whether an equivalent ratio is suitable for a SPECT tracer, 99mTc-MIP-1404, and to compare lesion and lesion-to-normal-organ ratios between the 2 radiotracers. Methods: Two cohorts of patients with mCRPC matched for age, prostate-specific antigen level, and total Gleason score, with either 99mTc-MIP-1404 SPECT/CT (n = 25) or 68Ga-PSMA-11 PET/CT (n = 25) scans, were included for analysis. Up to 3 lesions in each site (prostate/prostate bed, lymph nodes, bone and soft-tissue metastases) as well as normal liver, parotid gland, spleen, and mediastinal blood-pool SUVmax were measured. Results: 99mTc-MIP-1404 SPECT lesion SUVmax was not significantly different from 68Ga-PSMA-11 PET (median, 18.2 vs. 17.3; P = 0.93). However, 99mTc-MIP-1404 liver SUVmax was higher (median, 8.5 vs. 5.8; P = 0.002) and lesion-to-liver ratios were lower (median, 2.7 vs. 3.5; P = 0.009). There was no significant difference in parotid gland or splenic SUVmax or lesion-to-parotid gland ratios between the 2 tracers although there was a small difference in lesion-to-spleen ratios (P = 0.034). Conclusion: There are differences in biodistribution and, in particular, liver activity, between 68Ga-PSMA-11 and 99mTc-MIP-1404. Therefore, if 99mTc-MIP-1404 is used to assess eligibility for 177Lu-PSMA-617 therapy, a lower adjusted lesion-to-liver ratio should be used.

Previously Unreported Salivary Heterotopia of the TMJ – 23 Serous Choristomas of One Joint

<h3>Introduction</h3> Salivary gland choristomas of the soft tissues of the TMJs, independent of adjacent parotid glands, have not been previously reported. <h3>Objective</h3> To report a massive example of serous gland heterotopia of the TMJ soft tissues. Methods and Msaterials. 116 consecutive TMJ surgical samples from 57 subjects were microscopically reviewed for abnormalities. Of these, 27 joints contained previously undescribed heterotopic glandular lobules of parotid-like tissue (plus 2 mucus lobules), with no connection to parotid glands. The case of a 41 year of female with many years of joint dysfunction and severe pain was selected for specific description because she presented the most extreme example of this phenomenon. <h3>Results</h3> Two clusters comprising a total of 57 distinct lobules of mostly normal serous acinar tissue and ductal structures were embedded in or attached to the posterior-lateral ligament of the subject's left TMJ. The ligament itself was largely replaced by dense fibrous scar, with an embedded traumatic neuroma and an hypertrophied artery, while fossa curettings showed osteoarthritis. The salivary lobules appeared to represent 23 different "glands" measuring altogether 2.5 × 2.5 × 0.5 cm. Glandular parenchyma was histologically normal and mature serous tissue, except for 6 glands which showed almost complete oncocytic change, 7 showing focal regions of oncocytic change, and 2 showing acinar atrophy with stromal fibrosis and small numbers of lymphocytes (chronic sialadenitis). No large or secretory ducts were found. Serial sectioning confirmed that there was no connection to normal parotid gland. <h3>Conclusion</h3> We report a massive cluster of 23 serous gland choristomas within and attached to the posterolateral ligament of the left TMJ in a single individual. The ligament was severely scarred and some choristomas showed chronic sialadenitis, presumably from being repeatedly pressed into the joint spaces. Heterotopic serous tissue has not been previously reported from the TMJs.

Can the ultrasound echogenicity of normal parotid and submandibular glands be used as a reference standard for normal thyroid echogenicity?

PurposeThis study aimed to determine whether the normal parotid gland (PG) and submandibular gland (SMG) can be used as reference standards for normal thyroid echogenicity.MethodsIn total, 1,302 consecutive patients with normal salivary glands were included in this study. The echogenicity of the SMG and PG was assessed during real-time ultrasound examinations, and the glands were categorized as hyperechogenic, isoechogenic, and hypoechogenic relative to the thyroid parenchyma in patients without diffuse thyroid disease (group 1, n=1,106) and with diffuse thyroid disease (group 2, n=196). The frequency of the echogenicity categories of the normal PG and SMG was assessed according to patients’ age.ResultsIn group 1, the normal PG showed isoechogenicity in 94.0% and hypoechogenicity or hyperechogenicity in 6.0%, and the normal SMG showed isoechogenicity in 73.6% and hypoechogenicity in 26.4% of patients (P<0.001). There was no significant association of the frequency of isoechoic PG with age (P=0.834); however, there was a trend for an increasing frequency of isoechoic SMG with aging (22.9%-81.4%) (P<0.001). Similar findings were found in group 2 patients without decreased thyroid echogenicity.ConclusionThe normal PG was mostly isoechoic to the normal thyroid parenchyma, whereas the normal SMG showed hypoechogenicity at various frequencies according to age. The echogenicity of the normal PG can be used as an alternative reference standard for normal thyroid echogenicity; however, the normal SMG is not suitable for a reference standard when assessing thyroid nodule echogenicity in patients who have diffuse thyroid disease with decreased parenchymal echogenicity.

Assessment of hyperbaric oxygenation treatment response in parotid glands by T2 mapping following radiotherapy for head and neck tumours.

BackgroundThe study was designed to evaluate the influence of hyperbaric oxygenation therapy (HBOT) on the parotid gland in patients following radiotherapy for head and neck tumours.Patients and methodsHBOT response was monitored by 3T magnetic resonance imaging (MRI) using T2 mapping and subsequent measurement of mean T2 and T2 variability as well as by salivary tests (salivary flow, buffer capacity, and pH). Eighteen patients previously treated with irradiation doses between 50 and 80 Gy as well as 18 healthy gender and age matched controls were enrolled. MRI was performed prior to HBOT (40.2 ± 20 months after radiotherapy) and after 20 daily HBOT at 2.5 ATA (absolute atmosphere). Each HBOT consisted of breathing 100% oxygen for 90 minutes.ResultsSignificant differences in mean T2 prior to HBOT were observed between the ipsilateral irradiated (121 ± 20 ms), contralateral parotids (107 ± 21) and control group (96 ± 12 ms). A positive correlation in patients between T2 variability and irradiation dose was detected in contralateral parotids before HBOT (R = 0.489, p = 0.0287). In addition, negative correlations were observed between mean T2 in the ipsilateral as well as the contralateral gland and salivary flow before and after HBOT. Negative correlations between mean T2, T2 variability and pH of unstimulated saliva were also observed in the sides of parotid before and after HBOT.ConclusionsThe study confirmed that T2 mapping had a potential for monitoring the differences between irradiated and normal parotid glands. It could also be useful in the assessment of the glandular tissue response to HBOT.

Diagnostic grading of parotid lesions by conventional ultrasound: a pilot study.

To provide a graded diagnosis of benign and malignant lesions in the parotid gland by conventional ultrasound, and thus to predict the probability of malignancy of the lesions. Retrospective analysis of conventional ultrasound images of 150 patients with parotid lesions by two observers. Parotid lesions were classified into seven patterns and then categorised into eight grades: Grade 0, unsatisfied illustration on ultrasound; Grade 1, normal parotid gland; Grade 2, definitively benign; Grade 3, probably benign; Grade 4, indeterminate; Grade 5, probably malignant; Grade 6, highly suggestive malignant and Grade 7, already had malignant diagnosis. Combined with the pathological results, the conventional ultrasound diagnostic grade of parotid lesions was evaluated for predicting the probability of malignancy. There was excellent interobserver agreement of both readers for patterns and grades (K = 0.89 and 0.90, p < 0.01). The proportions of the malignancies in conventional ultrasound Grade 2, 3, 4, 5 and 6 according to the two readers 0 and 0, 0 and 0, 8.7% and 8.8%, 54.2% and 50%, 100% and 100%, respectively. The sensitivity, specificity and area under ROC curve were 64.0%, 91.2%, 0.809 and 64.0%, 89.6%, 0.802, respectively, using Grade 5 of the two readers as the best grade for diagnosing benign and malignant parotid lesions. The conventional ultrasound diagnostic grade of parotid lesions can be used to evaluate the risk of malignancy and will be helpful to improve the imaging diagnosis and clinical treatment.

Quantitative assessment of the parotid gland using computed tomography texture analysis to detect parotid sialadenitis

We aimed to quantitatively assess the parotid gland by using computed tomography (CT) texture analysis to detect parotid sialadenitis (PS). This retrospective case-control study included 43 patients with PS who underwent CT and magnetic resonance imaging (MRI). Parotid glands with an abnormal signal (STIR: High) on MRI were identified as showing PS. Patients with parotid gland tumors, bilateral PS, marked fatty degeneration, and severe artifacts on CT were excluded. The texture features of parotid glands with PS and the contralateral normal parotid glands were analyzed using the open-access software LIFEx. The regions of interest were manually placed by tracing contours of both parotid glands on CT images. The results were tested with the paired t-test (or Wilcoxon rank-sum test when appropriate). Receiver operating characteristic (ROC) curve analysis was performed to assess the ability of texture features to predict PS. Six gray level run length matrix features, 2 neighborhood gray level difference matrix features, and 5 gray level zone length matrix features displayed significant differences between PS and normal glands (P ≤ .047). ROC curve analysis showed acceptable accuracy in 4 texture features. CT texture analysis allowed quantitative assessment of parotid glands and may have the potential to detect PS.

Quantitative Analysis and Pathological Basis of Signal Intensity on T2-Weighted MR Images in Benign and Malignant Parotid Tumors.

ObjectiveTo investigate the value of the signal intensity on T2-weighted magnetic resonance (MR) imaging using quantitative analysis in the differentiation of parotid tumors.Materials and MethodsMR data of 80 pleomorphic adenomas (PAs), 68 Warthin tumors (WTs), and 34 malignant tumors (MTs) confirmed by surgery and histology were retrospectively analyzed. The signal intensities of tumor, normal parotid gland, spinal cord, and buccal subcutaneous fat were measured, and the signal intensity ratios (SIRs) between the tumor and the three references were calculated. Receiver operating characteristic curve was used to determine the optimal threshold and diagnostic efficiency of SIR for differentiating PAs, WTs, and MTs.ResultsThe area under the curve (AUC) of tumor to parotid gland SIR (SIRP), tumor to spinal cord SIR (SIRC), and tumor to buccal subcutaneous fat SIR (SIRF) for differentiating PAs and WTs was 0.922, 0.918, and 0.934, respectively. The sensitivity and specificity at an optimal SIR threshold were 86.3% and 91.2%, 80.0% and 97.1%, and 85.0% and 94.1%, respectively. The AUC of SIRP, SIRC, and SIRF for distinguishing PAs from MTs was 0.793, 0.802, and 0.774, respectively. The sensitivity and specificity at an optimal SIR threshold was 86.3% and 61.8%, 80.0% and 73.5%, and 82.5% and 73.5%, respectively. The AUC of SIRP, SIRC, and SIRF for distinguishing WTs from MTs was 0.716, 0.709, and 0.759, respectively. The sensitivity and specificity at an optimal SIR threshold were 61.8% and 82.4%, 55.9% and 82.4%, and 64.7% and 86.8%, respectively.ConclusionSIRP, SIRC, and SIRF on T2-weighted MR images had high diagnostic efficiency for differentiating between PAs and WTs, while SIRP and SIRC for differentiating between PAs and MTs, and SIRF for differentiating between WTs and MTs had relatively high diagnostic efficiency.

Feasibility evaluation of amide proton transfer-weighted imaging in the parotid glands: a strategy to recognize artifacts and measure APT value.

The feasibility and image quality of three-dimensional (3D) amide proton transfer (APT)-weighted (APTw) in parotid tumor lesions have not been well established in previous studies. This study aimed to evaluate the utility of APT imaging in parotid lesions and glands. Patients with parotid lesions received 3D turbo spin echo (TSE) APTw on a 3.0T scanner. Two radiologists, who were blinded to the clinical data, independently evaluated the APTw image quality using 4-point Likert scales (1= poor, 4= excellent) in terms of integrity and hyperintensity artifacts. An image quality selection protocol was built based on the two scores. Evaluable images (integrity score >1) and trustable images (integrity score >3 and hyperintensity artifacts score >2) were then enrolled for APTw value comparison between parotid lesions and glands. Forty consecutive patients were included in this study. Four patients were excluded due to severe motion (n=3) or dental (n=1) artifacts, and 36 patients received the APT sequence. Among these, more parotid tumor lesions (34/36, 94.4%) than normal parotid glands (23/31, 74.2%) revealed excellent integrity scores (score =4) (P=0.034). Most parotid tumor lesions (24/34, 70.6%) and glands (16/28, 57.1%) revealed no or little hyperintensity artifacts for diagnosis (scores 3 and 4). APT values of parotid lesions and glands in the evaluable groups were 2.11%±1.15% and 1.60%±1.56%, respectively, and the difference was not significant (P=0.197). APT values of parotid lesions and glands in the trustable groups were 1.99%±1.18% and 1.03%±1.09%, respectively, and the difference was statistically significant (P=0.018). 3D APTw could be used to differentiate parotid tumors and normal parotid glands; however, the technology still needs to be improved to remove artifacts. In our study, most APTw images of tumor lesions in parotid glands had acceptable image quality, and these APTw images are feasible for diagnostic use.

Diffusion tensor imaging of oral carcinoma: Clinical evaluation and comparison with histopathological findings

PurposeThis study aims to assess the usefulness of diffusion tensor imaging (DTI) as a noninvasive method for the evaluation of histological grade and lymph node metastasis in patients with oral carcinoma (OC). Materials and methodsThirty-six consecutive patients with histologically confirmed OC underwent examination by 3-T MRI. DTI was performed using a single-shot echo-planar imaging sequence with b values of 0 and 1000 s/mm2 and motion-probing gradients in 12 noncollinear directions. Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) maps were compared with histopathological findings. The DTI parameters were correlated with the histological grade of the OCs based on the World Health Organization grading criteria and the presence or absence of lymph node metastasis. ResultsThe FA values (0.275 ± 0.058) of OC were significantly lower than those of normal tongue, muscle, and parotid glands (P < 0.001 for all), and the MD, AD, and RD values (1.220 ± 0.149, 1.434 ± 0.172, and 1.019 ± 0.165 × 10−3 mm2/s, respectively) were significantly higher than their respective normal values (P < 0.001 for all). Significant inverse correlations with histological grades were shown for FA, MD, AD, and RD values in OC patients (r = −0.862, r = −0.797, r = −0.747, and r = −0.844, respectively; P < 0.001 for all). In addition, there was a significant difference in the FA values of metastatic and nonmetastatic lymph nodes (0.186 vs. 0.276), MD (0.923 vs. 1.242 × 10−3 mm2/s), AD (1.246 vs. 1.621 × 10−3 mm2/s), and RD (0.792 vs. 1.100 × 10−3 mm2/s; P < 0.001 for all). ConclusionsDTI may be clinically useful for the noninvasive evaluation of histological grade and lymph node metastasis in OC patients.

Expression of CD44v6 and COX-2 in pleomorphic adenomas and carcinomas of parotid gland

To investigate the correlation between CD44v6 and cyclooxygenase-2(COX-2) expression and recurrence and deterioration of pleomorphic adenoma of parotid gland. Immunohistochemistry was used to detect the expression of CD44v6 and COX-2 in 19 normal parotid tissues, 25 primary pleomorphic adenomas, 15 first recurrent pleomorphic adenoma, 15 second recurrent pleomorphic adenoma and 13 cancer in pleomorphic adenomas. The correlation between CD44v6 and COX-2 and the recurrence and deterioration of pleomorphic adenomas was evaluated using SPSS 15.0 software package. The positive expression rate of CD44v6 in normal parotid gland, primary pleomorphic adenoma, first recurrent pleomorphic adenoma, second recurrent pleomorphic adenoma and cancer was 5.26%, 44.00%, 60.00%, 93.37% and 100.00%, respectively;and the positive expression rate of COX-2 was 10.53%, 40.00%, 63.33%, 93.37% and 100.00%, respectively. There was significant difference in the positive expression intensity of CD44v6 and COX-2 among the groups (P<0.05). The positive expression rate and intensity of CD44v6 and COX-2 in normal parotid gland tissue were significantly lower than those in other groups (P<0.05). There was no significant difference in the positive expression rate and intensity of CD44v6 between primary pleomorphic adenoma and first recurrent pleomorphic adenoma (P>0.05). There was no significant difference in the expression intensity of COX-2 between the two groups (P>0.05), but the positive expression rate of COX-2 between the two groups was not significant(P>0.05). The positive expression rate and intensity of CD44v6 and COX-2 in the second recurrent pleomorphic adenoma were significantly higher than those in the first recurrent pleomorphic adenoma(P<0.05), but there was no significant difference between the two groups(P>0.05). CD44v6 in the second recurrent pleomorphic adenoma and cancer was significantly higher than that in the first recurrent pleomorphic adenoma(P<0.05). There was no significant difference in the expression rate and intensity of COX-2 (P>0.05). CD44v6 and COX-2 may play an important role in promoting occurrence, invasion, recurrence and deterioration of pleomorphic adenoma through synergistic action.

Conservative Surgical Treatment of Benign Parotid Tumors: Extracapsular Dissection

Parotid tumor resection, parotidectomy, is a surgical procedure that requires considerable experience from surgeons in most of the cases because of the risk of facial nerve damage. In addition, it is often times difficult to identify and preserve the facial nerve during the procedure, because it requires removal of a considerable amount of normal parotid tissue even when it is not related to the location of the tumor itself. Post-operative cosmetic problems and complications associated with inevitable removal of the normal parotid gland tissue cannot be ignored. For these reasons, parotidectomy has been evolved over the years to ensure the oncological safety, avoid complications, and improve functional and cosmetic results. Recently, the use and importance of extracapsular dissection (ECD) has become more recognized because it is a more conservative surgical method than partial superficial parotidectomy with preservation of facial nerve function, minimization of functional and cosmetic complications, and limited removal of unnecessary normal parotid gland tissue. Herein, we review the literatures related to ECD for benign parotid tumors and explain the efficacy of this emerging procedure based on the previous study results reported by the authors.

High expression of Livin serves as a predictive indicator for parotid gland tumors.

The aim of this study was to explore the expression of Livin in benign and malignant parotid gland tumors. We also investigate the role of Livin in the occurrence and progression of parotid gland tumors. Livin expression in 30 cases of normal parotid gland tissues, 40 cases of benign parotid gland tumors and 60 cases of malignant parotid gland tumors was detected by immunohistochemistry. The correlation between Livin expression and pathological characteristics of patients with parotid gland tumors was analyzed. The differentially expressed Livin in normal parotid gland tissues and malignant parotid gland tumors was determined by Western blot and quantitative Real Time-Polymerase Chain Reaction (qRT-PCR), respectively. Livin expression was unable to be detected in normal parotid gland tissues. The positive rate of Livin expression in benign and malignant parotid gland tumors was 17.50% and 71.67%, respectively (p<0.05). Livin expression was correlated to malignant level, clinical stage and tumor diameter in 60 cases of malignant parotid gland tumors (p<0.05). However, the positive rate of Livin expression was not correlated to lymph node metastasis, age and sex of patients with parotid gland tumors (p>0.05). Livin expression is closely related to the pathological progression of parotid gland tumors, which may serve as a hallmark in diagnosis, treatment and prognosis of patients with parotid gland tumors.