Osteotomy in the vertical ramus outside the mandibular foramen for tumours in the parapharyngeal space

IntroductionAlthough several techniques have been described to access the parapharyngeal space, tumour surgery in this area remains a challenge. This study investigated a simple and safe technique to access parapharyngeal space tumours.Material and methodsEight primary parapharyngeal space tumours were treated with osteotomy of the vertical ramus outside the mandibular foramen. The primary tumours were pleomorphic adenoma, schwannoma, Warthin's tumour, lipoma, chordoma, and adenoid cystic carcinoma. Tumour size ranged from 4 × 4 cm to 6 × 7 cm. Patients with malignant tumours who underwent surgical resection also received adjuvant dose-fractionated stereotactic radiotherapy.ResultsAll tumours were removed completely without rupture. No patient exhibited any permanent postoperative complication, malocclusion, or other dental complications from this surgical approach. One patient had slight transient postoperative facial paresis, which resolved spontaneously within 4 weeks. The patients were followed for 7–26 months, during which no recurrence was encountered.ConclusionsOsteotomy of the vertical ramus outside the mandibular foramen achieved good exposure and satisfactory aesthetic and functional results. This simple and safe technique facilitates the removal of infratemporal fossa tumours while preserving the inferior alveolar nerve.     

Stylomandibular tenotomy in the transcervical removal of large benign parapharyngeal tumours

We used a simple modification of the transcervical approach in a selected group of nine patients with large benign parapharyngeal space tumours, all of whom met the following inclusion criteria: The tumour was benign on fine needle aspiration, the encapsulated tumour was not attached to skull base or great vessels in the parapharyngeal space on imaging. Adequate exposure was achieved by just dividing the stylomandibular ligament and retracting the mandible anteriorly. It was possible to remove the tumours successfully and safely in all nine patients without the need for mandibulotomy or superficial parotidectomy. In seven cases, the tumour crossed the midline. There were no major perioperative neurological or vascular complications. On subsequent follow up, there were no clinical or radiological signs of residual or recurrent tumour.     

Sentinel lymph node biopsy with preoperative CT lymphography and intraoperative indocyanine green fluorescence imaging for N0 early tongue cancer: A long-term follow-up study

PurposeThis study evaluated the usefulness of sentinel lymph node (SLN) biopsy with preoperative computed tomographic lymphography (CTL) and intraoperative indocyanine green (ICG) fluorescence imaging for N0 early tongue cancer.MethodsTwenty-seven patients with N0 early oral tongue cancer underwent CTL with a 128-slice multi-detector row CT scanner to detect SLN on the day before resection of primary tumor and SLN biopsy under ICG fluorescence guidance. We identified the location and number of SLNs mapped by CTL and evaluated whether CTL-enhanced SLNs could be identified intraoperatively as ICG fluorescent lymph nodes. Prognosis was also evaluated.ResultsSLNs were detected by CTL in 26 of 27 patients (96.3%). The total and mean numbers of SLNs were 41 and 1.5, respectively. All SLNs enhanced by CTL could be identified intraoperatively as ICG fluorescent lymph nodes. Two SLNs were found under ICG fluorescent guidance in only one patient without SLN enhanced by CTL. Among the 27 patients, five (18.5%) had SLN with metastasis. Median follow-up was 76 months (range 44–82 months). During follow-up, three of 22 patients without SLN metastasis had occult cervical lymph node metastasis. The 5-year overall survival rate was 100%.ConclusionSLN biopsy with preoperative CTL and intraoperative ICG fluorescence imaging is a feasible and reliable procedure, without radioisotope tracers, for neck management in cases of early tongue cancer.     

Transoral robotic surgery of parapharyngeal space tumours: a series of four cases

Tumours arising from the parapharyngeal space (PPS) represent less than 1% of all head and neck tumours. Salivary gland tumours account for 40–50% of PPS lesions and are located in the pre-styloid parapharyngeal space. Pleomorphic adenomas represent 80–90% of salivary tumours in the PPS. Recently, transoral robotic surgery (TORS) has become common in head and neck surgery as a minimally invasive procedure. Four cases of benign PPS tumour treated with TORS are presented here. Preoperative diagnosis was conducted by fine needle aspiration biopsy and magnetic resonance imaging, and the results were used to plan the correct surgical approach. One case required a change of approach to conventional transoral blunt dissection. Patients required pain control and reported dysphagia symptoms for a period of weeks, but no nasogastric tube was needed at any time. This case series indicates that TORS is a safe surgical procedure for the excision of benign tumours of the PPS in selected cases.     

Giant Parapharyngeal Space Pleomorphic Adenoma of the Deep Lobe of Parotid Presenting as Obstructive Sleep Apnoea: A Case Report & Review of the Diagnostic and Therapeutic Approaches

Introduction

Salivary gland tumours constitute about less than 4 % of all head and neck tumours. Pleomorphic adenoma, also called benign mixed tumour, is the most common tumour of the salivary glands. About 80–90 % of these tumours occur in the major salivary gland mainly parotid gland and 10 % of them occur in the minor salivary glands.

Aims and Methods

Aim of this case report is to discuss the unique case of giant parotid pleomorphic adenomas arising in the deep lobe involving the parapharyngeal space and difficulty in respiration at sleep during nights repoted at this institute. The patient was undergoing treatment for obstructive sleep apnea syndrome when she reported at this institute for disturbed sleep. Diagnosis was based on computed tomography scan and magnetic resonance imaging and cytology by means of fine needle aspiration biopsy.

Conclusion

An exhaustive pre-operative diagnostic algorithm is mandatory before approaching such lesions involving parapharyngeal space. Fine needle aspiration biopsy is, in our opinion, mandatory to avoid histological surprises. The surgical approach varies according to the location of the tumour and should provide excellent visibility with wide surgical exposure to secure local neurovascular structures.     

Endoscopy-assisted transoral resection of large benign parapharyngeal space tumors

We have evaluated the outcomes of endoscopically-assisted resection of large benign tumours of the parapharyngeal space by an intraoral approach. Six patients with primary benign tumours were treated in this way. The lesions were pleomorphic adenomas, Warthin's tumour, and schwannoma. The sizes of the tumours varied from 4 × 4 cm to 7 × 7 cm. All tumours were removed completely without rupture and without damage to the facial nerve. No patient developed any permanent postoperative complications such as damage to the facial nerve, salivary fistula, or limited mouth opening. The cosmetic effects were excellent. The patients were followed up for 8 to 21 months without recurrence. Endoscopically-assisted transoral resection of large benign tumours of the parapharyngeal space is a simple and safe technique that achieves excellent aesthetic and functional results.     

Primary parapharyngeal tumours: a review of 21 cases

Background

The diagnostic and therapeutic procedures performed in a series of patients with primary parapharyngeal space (PPS) tumours treated at the ENT Departments of San Giovanni Bosco Hospital, Turin, and of the Pugliese-Ciaccio Hospital, Catanzaro, Italy, in the period 2001–2010 are evaluated.

Materials and methods

The retrospective review included 20 patients, 11 male and 9 female, average age of 41 years operated on for 21 primary PPS tumours. The most common tumours found were neurogenic neoplasms, while those of salivary origin were the next most common.

Results

There were 14 paragangliomas (7 originating from carotid glomus, 5 from vagal and 2 from tympanicum), 1 sympathetic chain schwannoma and 6 pleomorphic adenomas. All the tumours were benign in nature and gave rise to few signs or symptoms. Patients underwent preoperative computed tomography (CT) scan or magnetic resonance imaging (MRI) or both. Most contrast-enhanced masses were submitted to some type of angiography. Most of the surgeries were planned through imaging alone, as preoperative fine needle aspiration (FNA) biopsy was performed only in six cases. Four different approaches were adopted for tumour removal: transcervical, transcervical/transparotid, cervical-transparotid-transmandibular and infratemporal fossa approach. There was no operative mortality, though neurologic morbidity was significant. Follow-up, extended to a maximum of 11 years, did not reveal any recurrences. In conclusion, neurogenic tumours may be the most common of PPS masses. Surgery is the mainstay treatment and external approaches offer the potential for satisfactory tumour resection. Of such external approaches, transcervical and cervical/transparotid are the most often used in benign forms.

Conclusion

The number of perioperative complications encountered in this series confirms the difficulty of performing surgery in this complex area, even in benign cases. The chances of avoiding vascular damage and saving the trunks or most of the nerve fibres involved depend not only on the skill and experience of the surgeon but also on the anatomy of the lesion, the type of connection between the tumour and the nerve from which it originates and the distribution of neural fibres in or around the tumour mass.     

Primary pharyngeal tuberculosis presenting as a submucosal tumour

We describe a rare case of primary pharyngeal tuberculosis without pulmonary involvement in which the lesion was thought to be a submucosal tumour with overlying intact mucosa. A 58-year-old male attended the outpatient ward due to a globus sensation in the throat of 2-month duration. A swelling of the posterior oropharyngeal wall was found. The lesion was thought to be a submucosal tumour on computed tomography and magnetic resonance imaging. Primary pharyngeal tuberculosis was confirmed by histopathological examination and polymerase chain reaction (PCR) analysis. The patient underwent 26 weeks of treatment with anti-tuberculous agents. He has been followed up for 12 months without any signs of disease recurrence.     

Surgical management of deep lobe parotid tumours with and without involvement of the parapharyngeal space

The diagnosis and treatment of deep lobe parotid tumours is challenging because of the complex surgical accessibility. There is a lack of studies describing the differences between deep lobe tumours that do and do not occupy the parapharyngeal space (PPS). Patients treated for deep lobe tumours occupying the PPS (PPS group) and not occupying the PPS (non-PPS group) were analysed retrospectively. A total of 227 patients were treated surgically for deep lobe parotid tumours between 1990 and 2019. Sixty patients (26.4%) presented with tumours that involved the PPS (PPS group), while 167 (73.6%) presented with tumours that did not occupy the PPS (non-PPS group). The majority of the PPS group tumours were removed using a transcervical or transcervical–transparotid approach. PPS group tumours were larger (P < 0.001), and tumour spill occurred more frequently in this group (benign tumours: P = 0.002; malignant tumours: P = 0.033). Complication rates did not differ between the PPS and non-PPS groups. A transcervical or transcervical–transparotid approach is the preferred method for the management of deep lobe parotid tumours that occupy the PPS in our practice. Tumour spill occurred more frequently in the PPS group, which is most probably due to the larger tumour size and more complex accessibility.     

Head posture and pharyngeal airway volume changes after bimaxillary surgery for mandibular prognathism

PurposeThe purpose of this study was to evaluate head posture and the pharyngeal airway volume changes using 3D imaging after bimaxillary surgery in mandibular prognathism patients by null hypothesis.Materials and methodsCone-beam computed tomography (CBCT) scans were obtained for 25 mandibular prognathism patients before bimaxillary surgery (T1) and 6 months after surgery (T2). The head posture of each patient was assessed by measuring cranio-cervical angle on a midsagittal plane passing through the anterior nasal spine at T1 and T2. Additionally, the volume of each subject's pharyngeal airway was measured using InVivoDental 3D imaging software.ResultsThe cranio-cervical angle increased significantly 6 months after bimaxillary surgery (p < 0.01). The total volume of the pharyngeal airway slightly decreased (p > 0.05) at the same timepoints, while naso- and oro-pharyngeal airway volume decreased significantly (p < 0.05, p < 0.05). There was significant relationship between the changes of head posture and those of total airway volume (p < 0.05).ConclusionThe null hypothesis was rejected. Bimaxillary surgery resulted in significant head flexion and a slight decrease in total pharyngeal airway volume.     

Pharyngeal airway space,hyoid bone position and head posture after orthognathic surgery in Class III patients

Objective:To determine the effect of orthognathic surgery on pharyngeal airway in Class III patients and to (1) compare the results of different surgical techniques, (2) determine the change at the position of the hyoid bone, and (3) evaluate the craniocervical posture changes related to pharyngeal airway change.Materials and Methods:Forty-eight Class III adult patients were included in the study to assess airway space after orthognathic surgery. Nine patients were treated with maxillary advancement, seven patients were treated with mandibular set back, and 32 patients were treated with bimaxillary surgery. Cephalometric records were taken before treatment, after surgery, and about 1 year after surgery (at the end of the treatment).Results:No differences were determined at the position of hyoid bone and craniocervical posture. Nasopharyngeal area was significantly increased in all groups (P < .05). Oropharyngeal area and SPSS and IPS parameters were significantly decreased after mandibular set back operation (P < .05). In bimaxillary and maxillary advancement groups, PPS parameter was significantly increased (P < .01), and IPS parameter was significantly decreased (P < .05). No differences were detected at oropharyngeal and hypopharyngeal areas in bimaxillary and maxillary advancement groups.Conclusion:Different surgical procedures have different effects on pharyngeal airway space.     

Anatomical restrictions in the transsphenoidal,transclival approach to the upper clival region: A cadaveric,anatomic study

ObjectiveTumours in the clival region are difficult to remove surgically. Before the 1970s, clival tumours had very high mortality and morbidity rates.MethodsAn anatomic dissection was performed on 24 spheno-occipital bone blocks obtained from 28 adult cadavers. The internal carotid artery, paraclival carotid tubercle, sixth cranial nerve and dorsum sellae in the upper clival region were analyzed qualitatively and quantitatively. For the histological evaluation, 4 samples were decalcified and sagittal sections were cut. From the eight blocks obtained, 32 incisions were made in the axial plane, and the tissue was analyzed.ResultsUsing microscopy, a clival recess was clearly identified in 15 of the 24 (62.5%) samples. Paraclival carotid tubercles were observed in 19 (79.16%) of the samples. In the upper clival and petroclival region, the sixth cranial nerve had directional changes at the dural porus, the petrous apex and the lateral wall of the cavernous segment of the internal carotid artery. At the dorsum sellae level, the distance between the medial surfaces of both internal carotid arteries was a mean of 15.33 ± 2.12 mm. This distance at the pharyngeal tubercle was a mean of 38.95 ± 4.67 mm. On all the histological sections, the distance of the sixth cranial nerve from the dural porus to the cavernous sinus was within the basilar plexus, along with the subarachnoid membranes around it. On the petrous apex level, the sixth cranial nerve was fixed to the petrous apex and the internal carotid artery with connective tissue formed by dense collagen fibres. The sixth cranial nerve and the internal carotid artery are tightly surrounded by dense collagen connective tissue, and the relative proximity between the carotids on the dorsum sellae level can be easily damaged during the transsphenoidal–transclival approach. Similarly, due to the ligamentous fixation on the dural porus and the petrous apex surfaces, there is a high risk of injury to the carotid artery and sixth cranial nerve.ConclusionThis study determines the relationship between the sixth cranial nerve and the internal carotid artery at the upper clivus and to provide morphologic details that is essential for the risks of transclival surgery.     

吲哚菁绿荧光成像技术在口腔鳞癌治疗中的应用：中国专家共识

吲哚菁绿（indocyanine green,ICG）荧光成像是一种基于ICG增强的渗透性和滞留效应（enhanced permeability and retention effect,EPR）的活体组织实时近红外显像技术,临床上可对实体肿瘤及其周围组织进行差异显像,评估肿瘤范围及手术切缘。该荧光成像技术用于口腔鳞癌（oral squamous cell carcinoma,OSCC）外科治疗尚处于起步阶段,在适应证、操作流程、注意事项等方面均缺乏相应规范。在前期开展的ICG近红外荧光成像辅助OSCC外科治疗的多中心临床研究基础上,经国内多家医学院校口腔颌面外科专家的共同商讨,参考国内外相关文献,形成ICG荧光成像技术在OSCC治疗中的应用专家共识,以期指导OSCC外科治疗的临床实践。     

Predictability of pharyngeal airway space dimension changes after orthognathic surgery in class II patients: A mathematical approach

IntroductionAngle Class II malocclusion due to mandibular retrognathia is a common dentofacial deformity. It is well known that mandibular advancement increases pharyngeal airway dimensions. The aim of this study was to evolve a mathematical method for predicting posterior pharyngeal airway space (PAS) changes based on 2D lateral cephalographic radiographs (LCRs) and expected extent of mandibular advancement prior to BSSO.Materials and methodsLinear regression analyses were performed in order to investigate the relation between the posterior airway space and mandibular advancement. LCRs where carried out to assess skeletal landmarks and pharyngeal airway space pre- (T0) and postoperatively (T1). To detect changes postoperatively, the posterior airway space was divided into three units: nasopharyngeal airway space (superior airway space — SPAS), oropharyngeal airway space (mid airway space — MAS) and hypopharyngeal airway space (inferior airway space — IAS). The differences between the distances of distinct measurement points (DIFF) were measured pre- and postoperatively. DOA referred to the distance of mandibular advancement and DP to the distance between the measurement points preoperatively. The parameters a, b₁ and b₂ were the regression coefficients that were determined separately for each unit (SPAS, MAS, and IAS).Results49 patients (16 male and 33 female) with a mean age of 27.2 years (SD: 10.09), ranging from 18 to 51 years, who underwent mandibular advancement surgery (BSSO) were enrolled in this study. The mean distance of mandibular advancement was 5.05 mm (SD: 1.63). Regarding SPAS and IAS, mandibular advancement did not affect dimensions significantly: SPAS DIFF, 0.33 mm ± 1.13 mm (b₁, p = 0.0881; b₂, p = 0.087); IAS DIFF, 0.66 mm ± 2.45 mm (b₁, p = 0.342; b₂, p = 0.765). DOA and DP did not influence DIFF significantly in both sections. Regarding MAS, the mean effect of mandibular advancement was an expansion of 2.47 mm ± 2.24. The linear regression model showed a statistically significant (b₁, p = 0.0064; b₂, p = 0.0240) influence of DOA and DP on DIFF in posterior airway dimensions pre- and postoperatively.DiscussionBased on preoperative LCR imaging data, a linear regression model was developed as a mathematical approach to allow prediction of PAS development in patients with Angle Class II malocclusions of different degrees. Increasing mandibular advancement was shown to be linked to increasing PAS, while a greater distance between the measuring points preoperatively led to smaller predicted PAS increases postoperatively.ConclusionPredicting pharyngeal airway space (PAS) development after mandibular advancement by analysing lateral cephalometric radiographs (LCR) may be useful in the screening and treatment of obstructive sleep apnea syndrome (OSAS) patients. Our mathematical approach is a simple and sustainable prediction tool based on LTR data for patients with Class II malocclusions.     

Minimal invasive biopsy of intraconal expansion by PET/CT/MRI image-guided navigation: A new method

Intraorbital tumours are often undetected for a long period and may lead to compression of the optic nerve and loss of vision. Although CT, MRI's and ultrasound can help in determining the probable diagnosis, most orbital tumours are only diagnosed by surgical biopsy. In intraconal lesions this may prove especially difficult as the expansions are situated next to sensitive anatomical structures (eye bulb, optic nerve). In search of a minimally invasive access to the intraconal region, we describe a method of a three-dimensional, image-guided biopsy of orbital tumours using a combined technique of hardware fusion between ¹⁸F-FDG Positron Emission Tomography (¹⁸F-FDG PET), magnetic resonance imaging (MRI) and Computed Tomography (CT).Method and materialWe present 6 patients with a total of 7 intraorbital lesions, all of them suffering from diplopia and/or exophthalmos. There were 3 female and 3 male patients. The patients age ranged from 20 to 75 years. One of the patients showed beginning loss of vision. Another of the patients had lesions in both orbits. The decision to obtain image-guided needle biopsies for treatment planning was discussed and decided at an interdisciplinary board comprising other sub-specialities (ophthalmology, neurosurgery, maxillofacial surgery, ENT, plastic surgery). All patients underwent 3D imaging preoperatively (¹⁸F-FDG PET/CT or ¹⁸F-FDG PET/CT plus MRI). Data was transferred to 3D navigation system. Access to the lesions was planned preoperatively on a workstation monitor. Biopsy-needles were then calibrated intraoperatively and all patients underwent three-dimensional image-guided needle biopsies under general anaesthesia.Results7 biopsies were performed. The histologic subtype was idiopathic orbital inflammation in 2 lesions, lymphoma in 2, Merkel cell carcinoma in 1, hamartoma in 1 and 1 malignant melanoma. The different pathologies were subsequently treated in consideration of the actual state of the art. In cases where surgical removal of the lesion was performed the histological diagnosis was confirmed in all cases.ConclusionThere is a wide range of possible treatment modalities for orbital tumours depending on the nature of the lesion. Histological diagnosis is mandatory to select the proper management and operation. The presented method allows minimal-invasive biopsy even in deep intraconal lesions, enabling the surgeon to spare critical anatomical structures. Vascular lesions such as cavernous haemangioma, tumour of the lacrimal gland or dermoid cysts present a contraindication and have to be excluded.     

Giant osteochondroma derived from pterygoid process of sphenoid

Osteochondroma is rarely found in oral and maxillofacial regions. The majority of reported osteochondromas occurred in mandibular areas; their occurrence in bones developed by intramembranous ossification is extremely rare. In this report, a case of osteochondroma arising from the pterygoid process of the sphenoid is described. Radiological investigations showed a large bony mass under the left great wing of the sphenoid and involving the left parapharyngeal space. The tumour was compressive to the mandibular ramus and pharyngeal cavity, causing marked disturbance of mouth opening and secretory otitis media. Histopathological examination confirmed the lesion to be osteochondroma.     

Cone-beam evaluation of pharyngeal airway space in adult skeletal Class II patients with different condylar positions

Objectives:To test the null hypothesis that there is no significant difference in pharyngeal airway space among adult skeletal Class II patients with different condylar positions using cone-beam computed tomography (CBCT).Materials and Methods:The CBCT records of 60 patients with skeletal Class II malocclusion (ANB angle ≥ 4°, Wits ≥ 0) were selected from the CBCT database. According to the condyle position, the patients were divided in three groups: anterior group (CD ≤ −12%), centric group (−12% ≤ CD ≤ +12%), and posterior group (CD ≥ +12%). Three-dimensional (3D) pharyngeal airway models were reconstructed using InvivoDental software 5.1.3. The volume and area of the pharyngeal airway space were measured in the 3D airway model.Results:The volume and area of the pharyngeal airway space in the centric group were significantly smaller than those in the posterior group (P < .01). The volume and area of the pharyngeal airway space were smallest in the anterior group and significantly increased in the centric and posterior groups (P < .001).Conclusions:The null hypothesis was rejected. Significant differences were noted in pharyngeal airway space among adult skeletal Class II patients with different condylar positions.     

The feasibility of locating the affected bone of BRONJ with indocyanine green

The morbidity of bisphosphonate‐related osteonecrosis of the jaw (BRONJ) is also increasing with the use of bisphosphonates (BPs). Removing affected bone accurately is the most effective treatment. This study aimed to explore the feasibility of Indocyanine green (ICG)‐based Near‐Infrared fluorescence (NIF) imaging to remove BRONJ affected bone. Firstly, the rat model of BRONJ was constructed. And 5 mg/kg ICG were injected via tail vein, after 12 hr, the affected and healthy bone were dissected for ICG‐based NIF imaging and quantification detection of fluorescence intensity. Finally, all the bone samples were sent for further pathological examination. All the affected bone tissues in rat BRONJ model were fluorescence developed with ICG. And the fluorescence developed regions were further confirmed as affected bone tissues with pathological examination. The fluorescence intensity in affected bone tissues, adjacent, and opposite bone tissues was 1.93*107 ± 2.08*106, 1.19*106 ± 2.33*105, and 1.24*106 ± 1.57*105, respectively (p < .05). Conclusions It was feasible that the extent of affected bone in rat model with BRONJ could be estimated intraoperative via ICG‐based NIF imaging. This novel approach would become an auxiliary method in the treatment of patients with BRONJ in the future.     

Evidence of phenotypic stability after transduction of fluorescent proteins in two human tongue cancer cell lines

ObjectivesThis study investigated the phenotypic stability and biological properties of two human tongue cancer cell lines after transduction of fluorescent proteins.DesignThe human tongue cancer cell lines UM1 and UM2 were cultured with GFP and RFP lentiviral particles stock for 72 h. Cells with successful transduction of fluorescent proteins were selected in a medium containing G418 antibiotics for two weeks. The proliferation rates of parental and transduced cell lines were evaluated by their population doubling time (PDT). Transduction efficiency was assessed by fluorescence microscope and flow cytometry. The transduced cells in passage 1, 2, 10, 20 and 30 were collected to check the stability of fluorescent protein expression. Phenotypic stability of the transduced cells was detected by means of cell morphology, cell surface markers and cell function evaluating essay.ResultsThe proliferation rates of the transduced cell lines showed no significant difference compared to their parental cells. Successful transduction with high efficiency (99% up) was demonstrated. High fluorescence expression on both transduced cells was detected until the thirtieth generation. UM1 and UM1-GFP displayed mesenchymal cell characteristics, while UM2 and UM2-RFP cell lines showed properties characteristic of epithelial.ConclusionsTwo human tongue cancer cell lines of epithelial and mesenchymal phenotype respectively, have been successfully labelled with green and red fluorescent proteins. The fluorescence maintained a high expression rate over thirty generations without influencing the original morphological phenotype and cadherin expression.     

Salivary levels and immunohistochemical expression of selected angiogenic factors in benign and malignant parotid gland tumours

Objectives

Angiogenesis underlies tumour growth and metastasis through hepatocyte growth factor (HGF), epithelial growth factor (EGF), and vascular endothelial growth factor (VEGF). The aim of this study was to determine the levels of VEGF, EGF, HGF, HGFR (hepatocyte growth factor receptor), and SRSF1 (serine-rich protein splicing factor-1) in patients with parotid gland tumours and in healthy controls via ELISA in parotid saliva. Immunohistochemical expression of anti-angiogenic isoform of VEGF₁₆₅b subunit, VEGFR1, VEGFR2, and microvessel density (CD34) were assessed in the tumour tissue and in the non-tumorous surrounding margins.

Materials and methods

The study included 48 patients with benign and malignant parotid gland tumours and 15 healthy controls.

Results

Comparison of VEGF, EGF, and HGF in tumour and non-tumorous tissues showed no significant differences and no correlations with tumour stage. The salivary VEGF concentration was significantly higher in patients with pleomorphic adenoma and Warthin’s tumour. No significant correlation was found between expression of VEGF₁₆₅b and VEGFR2 in tumours and non-tumor surgical margins.

Conclusions

The increased salivary VEGF reflects changes in affected parotid glands, but it cannot be used as a prognostic and differentiative factor for parotid tumours.

Clinical relevance

Reciprocal relations between growth factors suggest an overlapping pathway of secretion and activity.