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.

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.

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.

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.

Varix of the retromandibular vein within the parotid gland: case study.

OBJECTIVE: To report a case of varix of the retromandibular vein within the parotid gland. METHODS: Case report, and discussion of the appropriate selection and use of radiological investigation techniques. RESULTS: A 64-year-old lady who presented with unilateral tinnitus underwent a magnetic resonance imaging scan to exclude a vestibular schwannoma. The magnetic resonance scout images revealed an incidental finding of a hyperechoic mass within the parotid gland. The mass was most consistent with a pleomorphic adenoma. Ultrasound-guided fine needle aspiration cytology was arranged; the ultrasound identified the mass as a varix of the retromandibular vein and fine needle aspiration cytology was not performed. CONCLUSION: A varix of the retromandibular vein is a very rare cause of a parotid mass. Appropriate radiological investigations can prevent unnecessary invasive investigations or procedures.

[Capabilities of ultrasound study in the differential diagnosis of neoplasms of the major salivary glands].

Seventy patients aged 20 to 75 years with suspected parotid gland disease were examined to study the capabilities of an ultrasound study in the diagnosis of neoplasms of the major salivary glands. B-mode ultrasonography and color Doppler imaging presented a means of detecting the presence of masses in the gland, their topography and dimensions, and specific vascularization, which allowed the option and scope of treatment to be planned.

Effect of irradiation on microvascular endothelial cells of parotid glands in the miniature pig.

PURPOSE: To evaluate the effect of irradiation on microvascular endothelial cells in miniature pig parotid glands. METHODS AND MATERIALS: A single 25-Gy dose of irradiation (IR) was delivered to parotid glands of 6 miniature pigs. Three other animals served as non-IR controls. Local blood flow rate in glands was measured pre- and post-IR with an ultrasonic Doppler analyzer. Samples of parotid gland tissue were taken at 4 h, 24 h, 1 week, and 2 weeks after IR for microvascular density (MVD) analysis and sphingomyelinase (SMase) assay. Histopathology and immunohistochemical staining (anti-CD31 and anti-AQP1) were used to assess morphological changes. MVD was determined by calculating the number of CD31- or AQP1-stained cells per field. A terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) apoptosis assay was used to detect apoptotic cells. The activity of acid and neutral Mg(2+)-dependent SMase (ASMase and NSMase, respectively) was also assayed. RESULTS: Local parotid gland blood flow rate decreased rapidly at 4 h post-IR and remained below control levels throughout the 14-day observation period. Parotid MVD also declined from 4 to 24 hours and remained below control levels thereafter. The activity levels of ASMase and NSMase in parotid glands increased rapidly from 4 to 24 h post-IR and then declined gradually. The frequency of detecting apoptotic nuclei in the glands followed similar kinetics. CONCLUSIONS: Single-dose IR led to a significant reduction of MVD and local blood flow rate, indicating marked damage to microvascular endothelial cells in miniature pig parotid glands. The significant and rapid increases of ASMase and NSMase activity levels may be important in this IR-induced damage.

A rare cause of a parotid mass: spontaneous pseudoaneurysm of the superficial temporal artery.

The authors describe a rare presentation of a spontaneous pseudoaneurysm of the superficial temporal artery which mimicked a parotid neoplasm. The clinical presentation, possible aetiology, diagnosis, and management of this condition are discussed.

New insights in the vascular supply of the human parotid gland - consequences for parotid gland-sparing irradiation.

BACKGROUND: Xerostomia is caused by irradiation for head and neck cancer, depending on the dose to the parotid gland. To investigate which part of the parotid gland has to be spared with radiotherapy, detailed information about the vascular supply of the parotid gland is necessary. METHODS: Arterial vessels of the head of a human cadaver were colored. A 3-dimensional reconstruction of the parotid gland and the arterial vessels was made and analyzed. RESULTS: Five arterial vessels were responsible for the vascular supply of the parotid gland: the posterior auricular artery, 2 branches so far unnamed, the superficial temporal artery, and the transverse facial artery. All arteries were branches off the external carotid artery, and supplied different parts of the parotid gland. CONCLUSIONS: This study describes the detailed vascular supply of the human parotid gland. These results may contribute to improve parotid sparing radiotherapy, thus reducing complications such as xerostomia in the future.

Perfusion characteristics of late radiation injury of parotid glands: quantitative evaluation with dynamic contrast-enhanced MRI.

We aimed to quantitatively investigate the alteration of parotid perfusion after irradiation using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) based on a two-compartment tracer kinetic model. This study enrolled 19 patients (53.2 +/- 14.9 years) treated by head and neck radiotherapy and 19 age-relevant and sex-matched subjects as a control group. Perfusion parameters (K ( el ), k (21) and A) of parotid glands were analyzed based on the Brix model from T1-weighted DCE-MRI. Suitability of the Brix model was evaluated via Monte Carlo simulation for the goodness-of-fit. Analysis of nonlinear goodness-of-fit showed that the Brix model is appropriate in evaluating the parotid perfusion (R(2) = 0.938 +/- 0.050). The irradiated parotid glands showed significantly lower K ( el ) (P < 0.0005) and k (21) (P < 0.05) and consequently significantly higher value of peak enhancement (P < 0.0005) and time-to-peak (P < 0.0005) compared with non-irradiated ones, suggestive of gradual and prolonged accumulation and delayed wash-out of contrast agent due to increased extracellular extravascular space and decreased vascular permeability in the irradiated glands. Linear regression analysis showed dose-dependent perfusion changes of the irradiated parotid glands. We conclude that quantitative DCE-MRI is a potential tool in investigating parotid gland perfusion changes after radiotherapy.