The diagnostic value of Superb Microvascular Imaging in identifying benign tumors of parotid gland.

BACKGROUND: We compared the ultrasound features, superb microvascular imaging (SMI) and micro vessel density (MVD) of pleomorphic adenoma (PA), Warthin's tumor (WT) and basal cell adenoma (BCA) to explore the clinic value of SMI in differential diagnosis of benign tumors of parotid gland. METHODS: The vascular distributions and grade by color doppler flow imaging (CDFI) and SMI, as well as vascular index (VI) of 249 parotid gland masses from 217 patients were analyzed. RESULTS: The internal echogenicity of BCA are more homogeneous in comparing with WT and PA(P < 0.05). By SMI, the vascular distribution and vascular grade in PA were mainly peripheral (33.1%) and avascular (25.7%), Grade 1 (27.8%) and Grade 0 (25.7%). WT were mainly central (31.3%) and mixed distribution (34.9%), in Grade 3 (37.3%) and Grade 2 (36.2%). BCA was mainly peripheral (33.3%) and mixed distribution (33.3%), in Grade 2 (33.3%) and Grade 3 (33.3%). The overall detection rate of SMI for vascular Grade 2 and 3 was significantly higher than that of CDFI (P < 0.05). Both VI and MVD were lowest in PA, highest in WT (P < 0.001). The VI by SMI was correlated with MVD (P < 0.001). The correlation index between vascular distribution and grade by SMI and MVD were significantly higher than CDFI. CONCLUSION: SMI can provide low-velocity blood flow information, which is helpful for the differential diagnosis of common benign tumors of parotid gland, and is expected to be more widely used.

Parotid Gland Venolymphatic Malformation Presentation As Macroglossia.

Venolymphatic malformations (VLM) are the rare congenital disorders but the parotid gland VLMs are the rarest. Most of the parotid lesions present with unilateral swellings. Aetiology is unknown. Interestingly, this case came in OPD with the macroglossia and only complaint was cosmetic problem. Diagnosis was confirmed on the basis of Magnetic resonance imaging which is gold standard. Doppler ultrasonography showed low flow. Intra lesion electro cautery was done. There is need to focus on malformations and work to find out the causes.

Relationship between impaired parasympathetic vasodilation and hyposalivation in parotid glands associated with type 2 diabetes mellitus.

We examined the relationship between hemodynamics in the three major salivary glands and salivary secretion in urethane-anesthetized and sympathectomized type 2 diabetic and nondiabetic rats via laser speckle imaging and by collecting the saliva. Lingual nerve stimulation elicited rapid increases in glandular blood flow and induced salivary secretion from the three glands in both diabetic and nondiabetic rats. In the parotid gland, the magnitude of blood flow increase and salivary secretion was significantly lower in the diabetic rats when compared with the nondiabetic rats; however, this was not observed in the other glands. Although the intravenous administration of acetylcholine increased blood flow in the parotid gland in a dose-dependent manner, the response was significantly lower in the diabetic rats when compared with the nondiabetic rats. Similarly, mRNA expression levels of M1 and M3 muscarinic acetylcholine receptors in the parotid gland were relatively lower in the diabetic rats compared with the nondiabetic rats. Our results indicate that type 2 diabetes impairs parasympathetic vasodilation and salivary secretion in the parotid gland and suggest that disturbances in the cholinergic vasodilator pathway may contribute to the underlying mechanisms involved in the disruption of parasympathetic nerve-mediated glandular vasodilation.

Evaluation of parotid glands in healthy children and adolescents using shear wave elastography and superb microvascular imaging.

OBJECTIVES: We aim to determine parotid gland elasticity values from healthy children and adolescents using shear wave elastography (SWE). We also define the degree of vascularity using superb microvascular imaging (SMI), power Doppler (PD), and color Doppler (CD) and compare SMI with CD and PD. MATERIALS AND METHODS: A total of 100 cases, comprising 50 girls and 50 boys, with ages ranging from 3 to 17 years were included in this prospective study. SWE, SMI, PD, and CD measurements were taken from both parotid glands, and the relationships with sex, age, and body mass index (BMI) were determined. The SMI was compared with the PD and CD. RESULTS: The median elasticity values measured with SWE were 8.37 ± 2.09 kPa and 1.68 ± 0.26 m/s on the right and 8.33 ± 2.04 kPa and 1.69 ± 0.26 m/s on the left. There were significant positive correlations present for those aged below and above 10 years and for BMI with elasticity values. The median vascular spot numbers measured using SMI, PD, and CD were 5 ± 1.70, 3.5 ± 1.45, and 2 ± 1.1 on the right and 4 ± 1.7, 4 ± 1.43, and 2 ± 1.05 on the left, respectively. The median values obtained with SMI were significantly higher than the median values obtained with both PD and CD. CONCLUSION: This study determined the reference SWE, SMI, PD, and CD values for normal parotid glands in healthy children and adolescents. Elasticity values were affected by age and BMI. There was no correlation between vascularity values and age, sex, or BMI. SMI provided more detailed information about vascularity compared with the other methods.

An unusual position of retromandibular vein: a surgical challenge in parotid surgeries.

A 44-year-old man presented with swelling in the left parotid region. The swelling was firm and Fine Needle Aspiration Cytology report proved pleomorphic adenoma. In the CT scan, the tumour was confined to the superficial lobe of parotid. So, left superficial parotidectomy was planned. Modified Wilson Blair's incision was used. On course of identifying the facial nerve, a large calibre vein was identified running vertically through the parotid substance. Assuming it as retromandibular vein, further dissection was carried out more meticulously. Marginal mandibularbranch of facial nerve was identified near the angle of mandible and retrograde dissection showed the cervicofacial division running medial to retromandibular vein with the main facial nerve trunk lying unusually medial and posterior to it. Adding to it, the temporofacial division was found 'forked' between the branches of retromandibular vein. These variations in head and neck venous channels are not that rare as we believe. All these variations have an embryological basis. Therefore, knowledge and understanding of this complex anatomy will help us preventing devastating complications like bleeding and facial nerve injury in such cases.

Auricular complications in parotid, temporal bone, infratemporal fossa, and lateral skull base surgery.

Neoplasms located in the parotid region, temporal bone, infratemporal fossa, and lateral skull base represent a challenge due to their difficult anatomic location and surrounding neurovascular structures. A variety of surgical approaches are appropriate to access this area, although several of them can place the auricular blood supply in danger. If the auricular blood supply is compromised, ischemia and, eventually, avascular necrosis of the auricle can occur. Auricular necrosis often can cause patients a delay in adjuvant radiation therapy and result in the need for additional reconstructive procedures. Therefore, it is imperative to identify risk factors associated with the development of this disabling complication. We conducted a retrospective review of 32 individuals undergoing treatment of benign and malignant lesions in the parotid gland, infratemporal fossa, and lateral skull base. To identify potential risk factors for auricular necrosis, the patients were analyzed based on the type of neoplasm (malignant or benign), risk factors affecting blood flow (diabetes mellitus, smoking history, prior radiation, prior surgery), body mass index, and the length of surgery. In our population examined, 3 instances of auricular necrosis occurred. None of the potential risk factors proved to be statistically significant (although malignant pathology approached significance at p = 0.07). Two of the patients required an auriculectomy with reconstruction. The third had multiple postoperative clinic visits for surgical debridement. Although no potential risk factors were statistically significant, surgeons should remain cognizant of the auricular blood supply while performing surgery via preauricular and postauricular approaches to this area.

Intravoxel incoherent motion imaging measurement of perfusion changes in the parotid gland provoked by gustatory stimulation: A pilot study.

PURPOSE: To demonstrate the feasibility of intravoxel incoherent motion imaging (IVIM) for quantification of perfusion changes in the parotid gland after gustatory stimulation. MATERIALS AND METHODS: Eight healthy volunteers underwent diffusion-weighted magnetic resonance imaging (MRI) of the neck at 3T with 11 dynamic acquisitions (9 b-values between 0 and 980 s/mm2 , 2:40 min each). After 5:20 minutes, a lemon-mint-drop was administered orally. Perfusion fraction (Fp ), pseudodiffusion (D*), tissue diffusion (Dt ) coefficients, and optimal b-value threshold were measured using a multistep variable b-value threshold fitting approach. Dynamic changes in the coefficients between three exemplary timepoints (baseline, after stimulation, after dissolution) were compared using a Mann-Whitney U-test with Bonferroni correction (P < 0.016 significance level). RESULTS: Mean values (95% confidence interval [CI]) for IVIM parameters at baseline were Fp : 0.11 (0.08-0.15), D*: 56.48 mm2 /s (39.71-98.27), Dt : 1.01 mm2 /s (0.84-1.06), b-value threshold: 30 s/mm2 (21.25-105). After stimulation: Fp 0.16 (0.15-0.24; P < 0.01), D* 93.83 mm2 /s (77.98-129.53, P = 0.25), Dt 0.93 mm2 /s (0.87-1.08, P = 0.94), b-value threshold 20 s/mm2 (13.75-26.25 s/mm2 , P = 0.10), reflecting the increase in tissue perfusion. After dissolution of the drop: Fp : 0.13 (0.11-0.18, P = 0.38), D*: 101.61 mm2 /s (90.68-144.55, P = 0.07), Dt : 0.91 mm2 /s (0.85-1.05, P = 0.64), b-value threshold: 15 s/mm2 (11.25-40, P = 0.38). CONCLUSION: The IVIM method allows for simultaneous quantification of changes in perfusion and diffusion effects after gustatory stimulation of the parotid gland. LEVEL OF EVIDENCE: 2 J. Magn. Reson. Imaging 2017;45:570-578.

Influence of amplitude-related perfusion parameters in the parotid glands by non-fat-saturated dynamic contrast-enhanced magnetic resonance imaging.

PURPOSE: To verify whether quantification of parotid perfusion is affected by fat signals on non-fat-saturated (NFS) dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and whether the influence of fat is reduced with fat saturation (FS). METHODS: This study consisted of three parts. First, a retrospective study analyzed DCE-MRI data previously acquired on different patients using NFS (n = 18) or FS (n = 18) scans. Second, a phantom study simulated the signal enhancements in the presence of gadolinium contrast agent at six concentrations and three fat contents. Finally, a prospective study recruited nine healthy volunteers to investigate the influence of fat suppression on perfusion quantification on the same subjects. Parotid perfusion parameters were derived from NFS and FS DCE-MRI data using both pharmacokinetic model analysis and semiquantitative parametric analysis. T tests and linear regression analysis were used for statistical analysis with correction for multiple comparisons. RESULTS: NFS scans showed lower amplitude-related parameters, including parameter A, peak enhancement (PE), and slope than FS scans in the patients (all with P < 0.0167). The relative signal enhancement in the phantoms was proportional to the dose of contrast agent and was lower in NFS scans than in FS scans. The volunteer study showed lower parameter A (6.75 ± 2.38 a.u.), PE (42.12% ± 14.87%), and slope (1.43% ± 0.54% s(-1)) in NFS scans as compared to 17.63 ± 8.56 a.u., 104.22% ± 25.15%, and 9.68% ± 1.67% s(-1), respectively, in FS scans (all with P < 0.005). These amplitude-related parameters were negatively associated with the fat content in NFS scans only (all with P < 0.05). CONCLUSIONS: On NFS DCE-MRI, quantification of parotid perfusion is adversely affected by the presence of fat signals for all amplitude-related parameters. The influence could be reduced on FS scans.

Vascular malformation with phleboliths involving the parotid gland: A case report with a review of the literature.

Phleboliths within the parotid gland are exceedingly rare. We report a case of a venous malformation with multiple phleboliths that involved the left parotid gland and extended into the extraparotid tissue in a 43-year-old woman. We also review 13 similar cases that have been reported since 1948, and we highlight the significance of distinguishing phleboliths from sialoliths because management of the two can be entirely different. Phleboliths in and around the salivary glands primarily affect the parotid and submandibular glands in adult women. Patients can present with recurrent, intermittent swelling that may be associated with food intake and hyposalivation. Any sialolithiasis located outside of its most common location in the submandibular glands must be investigated thoroughly before surgery.

Utility of (99m)Tc RBC Scintigraphy in Diagnosing Parotid Venous Malformations.

Venous malformations of the parotid glands are uncommon and can be difficult to confirm on routine anatomical imaging alone because of overlap of imaging features with other more common parotid lesions. (99m)Tc RBC scans combined with SPECT/CT offer a noninvasive way to diagnose parotid venous malformations without the need for biopsy. Combined with anatomical findings of phleboliths (when present), the diagnosis can be reliably determined. We present a case where MRI and biopsy were inconclusive, but the SPECT/CT was used to confirm the suspicion of a benign venous malformation.

Brief Report: Ultrasonographic Assessment of Salivary Gland Response to Rituximab in Primary Sjögren's Syndrome.

OBJECTIVE: To evaluate changes in salivary gland echostructure and vascularization after rituximab treatment in patients with primary Sjögren's syndrome (SS). METHODS: Twenty-eight patients with primary SS included in the multicenter, randomized, double-blind, placebo-controlled Tolerance and Efficacy of Rituximab in Primary Sjögren's Syndrome (TEARS) trial underwent salivary gland ultrasonography before the first placebo or rituximab infusion and then 6 months later. Trial inclusion criteria were scores of ≥50 mm on at least 2 of 4 visual analog scales (VAS) evaluating dryness, pain, fatigue, and global disease; and recent-onset (<10 years) biologically active primary SS and/or systemic primary SS. Patients were randomly assigned (1:1) to rituximab (1 gm at weeks 0 and 2) or placebo. Ultrasonography of both parotid and submandibular glands was performed to assess echostructure (using a semiquantitative score of 0-4, with improvement defined as a ≥1-point decrease), size of each gland, and vascularization based on the resistive index of the transverse facial artery of the parotid gland before and after lemon juice stimulation. RESULTS: Of the 28 patients, 5 (18%; 3 in the placebo group and 2 in the rituximab group) had clinically detectable bilateral parotid gland enlargement at baseline. Parotid parenchyma echostructure improved in 50% of the rituximab-treated patients versus 7% of the placebo-treated patients (P = 0.03). In the submandibular glands, echostructure also improved in a larger proportion of rituximab-treated patients, although the difference was not significant (36% versus 7% of placebo-treated patients; P = 0.16). Gland sizes and resistive index remained unchanged. CONCLUSION: Ultrasonography showed improved salivary gland echostructure in patients with primary SS receiving rituximab, with no changes in salivary gland size or vascularization, 6 months after the first infusion.

Modified temporomandibular joint disc repositioning with miniscrew anchor: part I--surgical technique.

Anterior disc displacement is one of the most common conditions affecting the temporomandibular joint. In the authors' previous publications, they reported on the basic technical elements of disc repositioning surgery. However, the present article presents some critical modifications that have allowed the safe and successful performance of this procedure during the past 3 years.

Vascular malformations that were diagnosed as or accompanied by malignant tumors.

BACKGROUND: Vascular malformations can mimic malignant tumors, and the coexistence of both types of lesions can limit and interfere with treatment. A consecutive series of vascular malformations that were treated and evaluated in a single institute and cases involving vascular anomalies combined with malignancies or malignancies that were treated as vascular anomalies were analyzed. OBJECTIVE: Absolute ethanol is used in the treatment and management of vascular malformations and is sometimes administered before a definitive diagnosis has been obtained, despite the fact that some vascular lesions are subsequently revealed to be malignant tumors. This study discusses such cases. MATERIALS AND METHODS: From January 2006 to August 2012, 139 patients were treated for vascular malformations at Nagasaki University Hospital and were followed up for a minimum of 1 year. RESULTS: Four malignant lesions coexisted with or were misdiagnosed as vascular malformations, including a malignant peripheral nerve sheath tumor located in the chest, a hemangiopericytoma of the palate, an adenoid cystic carcinoma of the cheek, and a squamous cell carcinoma of the cheek. Thus, malignant lesions were detected in 2.88% of cases in which vascular malformations were preoperatively diagnosed. CONCLUSION: When treating vascular malformations, it is advisable to be aware of the possibility of malignancy.

Vascular hamartoma of the parotid gland.

Hamartomas of the parotid gland are highly unusual. We present a case of a vascular hamartoma of the parotid gland arising as a 1.5 cm mass in a 5-year-old girl. As far as we are aware, no other case with the same features has been reported. We present this case to generate greater consideration of hamartomas as part of the differential diagnosis of parotid lesions, and to reflect over the criteria used to identify a hamartoma from other parotid lesions, as there appears to be some confusion in the literature.

Myopericytoma of the parotid region treated by extracapsular dissection.

Myopericytoma (MPC) is a vascular neoplasm exhibiting differentiation towards perivascular cells. Variable cytoarchitechtural features are visible within MPC, and there is much overlap between MPC, myofibroma and glomus tumours. MPC have a local recurrence rate of 10-20% and malignancy has been described in a few published cases. Previously, superficial parotidectomy has been recommended for MPC but, in this case, the surgical approach was via extracapsular dissection (ECD). A 66-year-old Caucasian man presented with a palpable mass arising from the superficial lobe of the right parotid gland. Following removal by ECD, the histopathological diagnosis of MPC was made. This is the first published report describing ECD of MPC associated with the parotid gland. ECD is preferable to superficial parotidectomy for small superficial lesions such as MPC, with similar oncological outcomes and fewer functional and aesthetic complications.

Multidisciplinary approach to lethal bleeding from an arteriovenous malformation in the external auditory canal.

Arteriovenous malformations (AVMs) are composed of abnormally connecting feeding arteries as well as draining veins and lack a regulatory system. Frequent recurrences and unpredictable behavior are their main problems. Potential mortality and morbidity associated with therapeutic procedures must be considered with these patients. Improper treatment often aggravates the condition, potentially rendering therapy more complex. A multidisciplinary approach, including an endovascular approach, surgical excision, and flap reconstruction, is considered to completely eradicate an AVM. This study introduces a complicated case of AVM with massive bleeding through the external auditory canal that was treated with a multidisciplinary approach.

Effects of large pressure amplitude low frequency noise in the parotid gland perivasculo-ductal connective tissue.

INTRODUCTION: In tissues and organs exposed to large pressure amplitude low frequency noise fibrosis occurs in the absence of inflammatory signs, which is thought to be a protective response. In the parotid gland the perivasculo-ductal connective tissue surrounds arteries, veins and the ductal tree. Perivasculo-ductal connective tissue is believed to function as a mechanical stabilizer of the glandular tissue. MATERIAL AND METHODS: In order to quantify the proliferation of perivasculo-ductal connective tissue in large pressure amplitude low frequency noise-exposed rats we used sixty Wistar rats which were equally divided into 6 groups. One group kept in silence, and the remaining five exposed to continuous large pressure amplitude low frequency noise: g1-168h (1 week); g2-504h (3 weeks); g3-840h (5 weeks); g4-1512h (9 weeks); and g5-2184h (13 weeks). After exposure, parotid glands were removed and the perivasculo-ductal connective tissue area was measured in all groups. We applied ANOVA statistical analysis, using SPSS 13.0. RESULTS: The global trend is an increase in the average perivasculo-ductal connective tissue areas, that develops linearly and significantly with large pressure amplitude low frequency noise exposure time (p < 0.001). DISCUSSION: It has been suggested that the biological response to large pressure amplitude low frequency noise exposure is associated with the need to maintain structural integrity. The structural reinforcement would be achieved by increased perivasculo-ductal connective tissue. CONCLUSIONS: Hence, these results show that in response to large pressure amplitude low frequency noise exposure, rat parotid glands increase their perivasculo-ductal connective tissue.

Introdução: Em tecidos e órgãos expostos a ruído de baixa frequência de alta amplitude ocorre fibrose na ausência de sinais inflamatórios, que se pensa ser uma resposta protetora. No tecido conjuntivo perivasculo-ductal da glândula parótida seguem artérias, veias e a árvore ductal. Crê-se que o tecido conjuntivo perivasculo-ductal funcione como um estabilizador mecânico do tecido glandular.Material e Métodos: Para quantificar a proliferação de tecido conjuntivo perivasculo-ductal em ratos expostos a ruído de baixafrequência de alta amplitude foram utilizados 60 ratos Wistar igualmente divididos em seis grupos. Um grupo mantido em silêncio, e os restantes 5 expostos a ruído de baixa frequência de alta amplitude continuamente: g1-168h (1 semana); g2-504h (3 semanas); g3-840h (5semanas); g4-1512h (9 semanas) e g5-2184h (13 semanas). Após a exposição, as parótidas foram removidas e o tecido conjuntivo perivasculo-ductal foi medido em todos os grupos. Foi efectuada análise estatística com ANOVA por SPSS 13.0.Resultados: A tendência é um aumento global das áreas do tecido conjuntivo perivasculo-ductal, que se desenvolve de forma linear e significativa com o tempo de exposição (p < 0,001).Discussão: Tem sido sugerido que a resposta biológica à exposição ao ruído de baixa frequência de alta amplitude está associada à necessidade de manter a integridade estrutural. O reforço estrutural seria conseguido através do aumento do tecido conjuntivo perivasculo-ductal.Conclusões: Assim, estes resultados mostram que o tecido conjuntivo perivasculo-ductal aumenta em resposta à exposição ao ruído de baixa frequência de alta amplitude.