Facial nerve function in carcinoma of the parotid gland

Surgery of major salivary gland cancers: REFCOR recommendations by the formal consensus method

OBJECTIVE

To determine the role of surgery of the primary tumor site in the management of primary major salivary gland cancer.

MATERIAL AND METHODS

The French Network of Rare Head and Neck Tumors (REFCOR) formed a steering group, which drafted a non-systematic narrative review of the literature published on Medline, and proposed recommendations. The level of adherence to the recommendations was then assessed by a rating group, according to the formal consensus method.

RESULTS

Treatment of salivary gland tumor is mainly surgical. The gold standard for parotid cancer is a total parotidectomy, to obtain clear margins and remove all intraparotid lymph nodes. For low-grade tumors, partial parotidectomy with wide excision of the tumor is acceptable in the case of postoperative diagnosis on definitive histology. In the event of positive margins on definitive analysis, revision surgery should be assessed for feasibility, and performed if possible.

CONCLUSION

Treatment of primary major salivary gland cancer is based on surgery with clear resection margins, as far away as possible from the tumor. The type of surgery depends on tumor location, pathologic type and extension.

How to perform prespecified subgroup analyses when using propensity score methods in the case of imbalanced subgroups

BACKGROUND

Looking for treatment-by-subset interaction on a right-censored outcome based on observational data using propensity-score (PS) modeling is of interest. However, there are still issues regarding its implementation, notably when the subsets are very imbalanced in terms of prognostic features and treatment prevalence.

METHODS

We conducted a simulation study to compare two main PS estimation strategies, performed either once on the whole sample ("across subset") or in each subset separately ("within subsets"). Several PS models and estimands are also investigated. We then illustrated those approaches on the motivating example, namely, evaluating the benefits of facial nerve resection in patients with parotid cancer in contact with the nerve, according to pretreatment facial palsy.

RESULTS

Our simulation study demonstrated that both strategies provide close results in terms of bias and variance of the estimated treatment effect, with a slight advantage for the "across subsets" strategy in very small samples, provided that interaction terms between the subset variable and other covariates influencing the choice of treatment are incorporated. PS matching without replacement resulted in biased estimates and should be avoided in the case of very imbalanced subsets.

CONCLUSIONS

When assessing heterogeneity in the treatment effect in small samples, the "across subsets" strategy of PS estimation is preferred. Then, either a PS matching with replacement or a weighting method must be used to estimate the average treatment effect in the treated or in the overlap population. In contrast, PS matching without replacement should be avoided in this setting.

Preservation of the Nerve to the Mylohyoid Muscle During Submental Island Flaps: An Anatomic Feasibility Study for Facial Nerve Reanimation Procedures

The submental island flap is an axial pattern pedicle flap widely used in head and neck surgery because of its ease and success. Indications of the submental island flap range from reconstruction for the malignant tumor resection to loss of temporal bone and facial skin due to trauma. Whereas, intraoperative facial nerve injury is not uncommon. We verified whether it was possible to localize the nerve to the mylohyoid muscle and reanimate the facial nerve during submental island flap procedures by preserving the mylohyoid muscle using human fresh cadaveric specimens. Six cadaveric heads were dissected and the position of the nerve to the mylohyoid muscle identified to the mylohyoid triangle documented. We identified the nerve to the mylohyoid muscle on all sides within the mylohyoid triangle and were able to separate the nerve from the submental island flap completely. Our results suggest that facial nerve reanimation using the nerve to the mylohyoid muscle can be used while reconstructing with a submental island flap in cases of intraoperative facial nerve injury.

A retrospective study of parotid gland tumors at a single institution

The aim of the present study was to analyze the clinical characteristics, surgical treatments and clinical outcome of patients with parotid gland tumors and to compare the results with those cited in the literature. A retrospective study was conducted in 140 patients (male, n=77; female, n=63) with parotid gland tumors who underwent parotidectomy at Hokuto Hospital Department of Otolaryngology-Head and Neck Surgery (Obihiro, Japan) between April 2007 and December 2021. Of the 140 patients enrolled, 118 (84.3%) patients had benign tumors, including 63 (45%) patients with pleomorphic adenomas and 43 (30.7%) patients with Warthin tumors, and 22 patients (15.7%) had parotid carcinoma. Comparison of the three groups of patients with parotid gland tumors indicated that pack years as an indicator of smoking status were significantly higher in patients with Warthin tumors than in those with parotid carcinomas (P=0.011) or pleomorphic adenoma (P<0.001). Fine-needle aspiration cytology (FNAC) was non-diagnostic for only 6 (4.3%) of 140 patients. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of FNAC by both conventional smear and liquid-based cytology (LBC) for parotid carcinomas were 70, 99, 93.3, 94.4 and 82.9%, respectively. Among the 22 patients with parotid carcinoma, extended total/total and superficial parotidectomy were performed in 10 (45%) and 11 (50%) cases, respectively. Total and selective neck dissection of the area from level II to I, II and III were performed in 6 (24%) and 7 (32%) patients, respectively. Postoperative radiotherapy (50 Gy) was performed in 15 (68%) patients. The overall survival (OS) and disease-free survival (DFS) rates at 5 years were 51.5 and 76.4%, respectively. Univariate analysis revealed that age >65 years was significantly associated with poorer 5-year OS (P<0.001) and DFS (P<0.001). Multivariate analysis revealed that an age of more than 65 years combined with high-grade histologic malignancy was associated with worse DFS (P=0.02; hazard ratio, 3.628; 95% confidence interval, 1.283-9.514). In conclusion, the clinical characteristics and treatment outcomes of parotid gland tumors were consistent with the results of previous reports. Smoking may be closely related to the pathogenesis of Warthin tumors. LBC potentially provides improved accuracy in FNAC.

Management of Malignant Salivary Gland Conditions

Salivary cancers are rare tumors that arise in major and minor salivary glands. Workup almost always includes fine-needle aspiration or core needle biopsy in select cases. Imaging with ultrasound, computed tomography, or MRI is also helpful, particularly with MRI to assess facial nerve involvement or skull base involvement. Preserving function of the facial nerve is of paramount importance, and the standard of care is to not sacrifice facial nerve except in instances of gross encasement and inability to dissect tumor off of the nerve. Adjuvant radiation and chemotherapy offer survival advantages for select patients.

Long-Term Facial Nerve Outcome in Primary Parotid Cancer Surgery: A Population-Based Analysis

OBJECTIVES/HYPOTHESIS

To determine immediate postoperative and long-term facial nerve dysfunction after parotid cancer surgery, risk factors, and the role of facial reanimation surgery.

STUDY DESIGN

Population-based long-term analysis for all new primary parotid carcinoma cases in Thuringia from 1996 to 2019.

METHODS

Data of the cancer registries of Thuringia, a federal state in Germany, were analyzed in combination with hospital-based data on facial function.

RESULTS

About 477 patients (42.3% women; median age: 68 years) were included. It was observed that 6.7% had a preoperative facial nerve dysfunction, 11.7% received a radical parotidectomy, that is, that 5% had a normal preoperative facial function but needed radical surgery because of intraoperative detection of tumor infiltration into the facial nerve. About 10.2% received facial nerve reconstruction surgery. Immediate postoperative facial nerve dysfunction in the other patients was observed in 34.4% of the patients. Advanced T classification (odds ratio [OR] = 2.140; confidence interval [CI] = 1.268-3.611; P = .004) and neck dissection (OR = 2.012; CI = 1.027-3.940; P = .041) were independent risk factors for immediate postoperative facial nerve dysfunction. In addition, 22.0% showed no recovery during follow-up. Advanced T classification (OR = 2.177; CI = 1.147-4.133; P = .017) and postoperative radiotherapy (OR = 2.695; CI = 1.244-5.841; P = .012) were independent risk factors for permanent postoperative facial nerve dysfunction.

CONCLUSION

Patients with primary parotid cancer are at high risk for long-term facial nerve dysfunction. It seems that the possibilities of facial reanimation surgery needs to be utilized even more effectively.

LEVEL OF EVIDENCE

3 Laryngoscope, 2021.

Symptoms and signs of parotid tumors and their value for diagnosis and prognosis: a 20-year review at a single institution

BACKGROUND

Detailed clinical features other than parotid mass have not been investigated in detail for parotid tumors. Symptoms and signs are useful for the differentiation of benign versus malignant, and may also be of value to determine the grade of malignancy and histological type as well as the assessment of prognosis.

METHODS

We reviewed symptoms and signs of 965 patients with benign tumors and 200 patients with malignant tumors. Symptoms and signs included pain/tenderness, adhesion to surrounding tissues, and facial nerve palsy. We reviewed the incidence in benign and malignant tumors, in histological type of benign tumors, and in grade and histology of malignant tumors. For each symptom or sign, covariates were analyzed, and their correlation with the prognosis was investigated.

RESULTS

The incidence of symptoms and signs was significantly higher in malignant than benign tumors, and more frequent in higher grade of malignancy. Facial nerve palsy was observed in 18.0% of malignant tumor cases, while none occurred in benign tumor cases. Pain/tenderness was more commonly observed in adenoid cystic carcinoma, while adhesion to surrounding tissues and facial nerve palsy were most frequently noted in salivary duct carcinoma. The prognosis of patients with these symptoms and signs was significantly poor.

CONCLUSION

A detailed investigation of symptoms and signs in parotid gland tumors is the first step that leads to the diagnosis of malignant tumors. Symptoms and signs are also useful for estimating the grade of malignancy and histological type, and they are important information for predicting prognosis.

Challenges with preoperative diagnosis of low/intermediate-grade carcinoma of the parotid gland: single-center study of 112 patients

BACKGROUND

The malignancy of parotid carcinoma varies, and accurate preoperative assessment of malignancy is important for selecting the appropriate treatment. However, the preoperative diagnosis of low/intermediate-grade carcinoma is difficult, and surgery may sometimes be performed without any prior knowledge of malignancy.

METHODS

The results of fine-needle aspiration cytology (FNA), imaging studies (MRI and US), physical examination, and frozen section biopsy (FSB) were evaluated in 112 patients with low/intermediate-grade parotid carcinoma.

RESULTS

The result of FNA was benign/inadequate specimen in 44.6% of the patients. In addition, the tumor was diagnosed as benign by MRI/US in 21.4% of the patients and 37.5% had no symptoms/signs of malignancy on physical examination. The rate of misdiagnosis as benign decreased when FNA was combined with imaging and physical findings. However, malignancy could not be diagnosed by FNA and FSB in 12.5% of the patients who were only found to have malignant tumors by the final pathological examination.

CONCLUSION

FNA shows a high misdiagnosis rate of malignancy in patients with low/intermediate-grade cancer. Therefore, it is necessary to carefully evaluate the findings of imaging studies and physical examination, and FSB should be conducted if such findings suggest the possibility of malignancy.

Nonmicrosurgical Grafting for Facial Nerve Branches with Permanent Sensational Functional Outcome

A 49-year-old man underwent intraoperatively modified procedure from superficial to radical parotidectomy with excision of the facial nerve 4 branches, temporal, zygomatic, buccal, and mandibular. We have dissected and harvested the branches of the great auricular nerve to repair the defects of the temporal, zygomatic, buccal, and mandibular nerves without microsurgery aid. The aims of the repair were just to mark the nerve endings, to try autologous grafting, and to avoid neuroma(s) formation, although neuroma(s) formations from motor nerves are rare. We did an immediate temporary nonmicrosurgical nerve grafting, and we have sutured each nerve anastomosis by 2-3 stitches of Prolene 6-0. We have observed facial nerve branches' recovery on the second month, even with radiation therapy, and then gradually more improvements on the third month and then on the sixth month of the follow-up. Finally, the procedure results in permanent sensational functional outcome after 1 year. Because we did not plan a microsurgical repair, this case report does not support any intended nonmicrosurgical procedures for facial nerve repair, but it raises questions for laboratory and animal investigations about the size of Prolene we have used, grip repair taking the epineurium and fascicle in mass closure, and the positive fast functional results. In surgical environments where microscope or microinstruments are lacking, one can still perform primary nerve grafting.

Perineural Invasion in Parotid Gland Malignancies

Objectives To investigate the clinical predictors and survival implications of perineural invasion (PNI) in parotid gland malignancies. Study Design Case series with chart review. Setting Tertiary care medical center. Subjects and Methods Patients with parotid gland malignancies treated surgically from 2000 to 2015 were retrospectively identified in the Head and Neck Cancer Registry at a single institution. Data points were extracted from the medical record and original pathology reports. Results In total, 186 patients with parotid gland malignancies were identified with a mean follow-up of 5.2 years. Salivary duct carcinoma (45), mucoepidermoid carcinoma (44), and acinic cell carcinoma (26) were the most common histologic types. A total of 46.2% of tumors were found to have PNI. At the time of presentation, facial nerve paresis (odds ratio [OR], 64.7; P < .001) and facial pain (OR, 3.7; P = .002) but not facial paresthesia or anesthesia (OR, 2.8, P = .085) were predictive of PNI. Malignancies with PNI were significantly more likely to be of advanced T and N classification, be high-risk pathologic types, and have positive margins and angiolymphatic invasion. PNI positivity was associated with worse overall (hazard ratio, 2.62; P = .001) and disease-free survival (4.18; P < .001) on univariate Cox regression analysis. However, when controlling for other negative prognosticators, age, and adjuvant therapy, PNI did not have a statistically significant effect on disease-free or overall survival. Conclusions PNI is strongly correlated with more aggressive parotid gland malignancies but is not an independent predictor of worse survival. Facial paresis and pain were predictive of PNI positivity, and facial paresis correlated with worse overall and disease-free survival.

The Prognostic Significance of Facial Nerve Involvement in Carcinomas of the Parotid Gland

IMPORTANCE AND BACKGROUND

Facial nerve (FN) palsy and perineural invasion (PNI) are adverse features in carcinomas of the parotid gland. FN sacrifice at the time of surgery is associated with significant morbidity. The role of adjuvant radiotherapy in patients with high-risk features, including FN involvement, remains unclear.

OBJECTIVE

Analyze the disease-free survival (DFS) and overall survival (OS) and the impact of tumor characteristics, including FN involvement, for patients treated with surgical resection for carcinoma of the parotid gland.

DESIGN

This is a retrospective chart review.

SETTING

University of Utah and Intermountain Healthcare, Utah.

PARTICIPANTS

A total of 129 patients who were treated with primary surgery for nonmetastatic primary malignancies of the parotid gland from 1988 to 2006.

INTERVENTIONS

Parotidectomy with or without adjuvant therapy.

MAIN OUTCOME(S) AND MEASURES

Kaplan-Meier analysis was used to obtain 5-year estimates of DFS and OS. Recurrence risk factors, particularly the impact of FN involvement, were analyzed.

RESULTS

Five-year DFS and OS rates were 79% and 78%, respectively. Thirty-two (28%) patients developed recurrent disease. Disease recurrence occurred in 64% of patients with both FN palsy and PNI, in 43% with FN palsy without PNI, in 27% with only PNI, and in 16% without either feature.

CONCLUSIONS AND RELEVANCE

FN involvement, particularly FN palsy, is a predictor of increased risk of recurrence and death. Radiotherapy cannot substitute for FN sacrifice in high-risk patients.

Margin Analysis: Malignant Salivary Gland Neoplasms of the Head and Neck

There are no established protocols for the optimum surgical margin required for salivary gland malignancies. Factors including histologic diagnosis and TNM stage have been shown to be important in prognosis and survival outcome and mandate special consideration of margin size. Salivary cancers are treated differently at different anatomic sites, and different histologic types show a propensity for major or minor glands. Low-grade malignancies are treated with soft tissue margins of 1 cm or less. The facial nerve is preserved unless infiltrated and encased. Adenoid cystic carcinoma and carcinoma ex pleomorphic adenoma require more complex planning to obtain negative margins.

Facial Nerve Reconstruction With Concurrent Masseteric Nerve Transfer and Cable Grafting

IMPORTANCE

Reconstruction of the facial nerve after radical parotidectomy is commonly performed with cable grafting, which is associated with slow recovery of nerve function and synkinesis.

OBJECTIVE

To describe facial nerve reconstruction after radical parotidectomy using concurrent masseteric nerve transfer and cable grafting.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective medical record review at a tertiary referral hospital included 9 patients who underwent concurrent masseteric nerve transfer and cable grafting for facial nerve reconstruction performed by a single surgeon from January 1, 2014, to October 31, 2015. Final follow-up was completed on March 14, 2016.

MAIN OUTCOMES AND MEASURES

Improvement in resting facial symmetry and oral commissure excursion and synkinesis.

RESULTS

Nine patients (6 women; mean age, 62.6 years; age range, 51-73 years) underwent immediate facial nerve reconstruction after radical parotidectomy using concurrent cable grafting and masseteric nerve transposition. All patients had return of oral commissure motion within 2 to 7 months after surgery with good excursion and minimal synkinesis.

CONCLUSIONS AND RELEVANCE

Masseteric nerve transposition can be combined with cable grafting to improve outcomes in facial rehabilitation after radical parotidectomy.

LEVEL OF EVIDENCE

4.

Facial Paralysis Secondary to Extensive Perineural Spread of Adenocarcinoma of the Parotid Gland Identified by PET/CT

Brain MRI in an 82-year-old man with presumed Bell's palsy revealed a clinically unsuspected right parotid gland mass but no other acute findings. Biopsy revealed poorly differentiated adenocarcinoma. Staging F-FDG PET/CT revealed an FDG-avid parotid mass, abnormal FDG uptake along the course of the facial nerve from mass to skull base, and multiple FDG-avid right level II neck lymph nodes and hepatic metastases. The PET/CT findings and prolonged clinical course suggest that diffuse perineural spread of tumor from a smoldering parotid neoplasm, and not idiopathic Bell's palsy, was responsible for the patient's facial paralysis.

Reconstruction of facial nerve after radical parotidectomy

CONCLUSION

Most patients benefitted from immediate facial nerve grafting after radical parotidectomy. Even weak movement is valuable and can be augmented with secondary static operations. Post-operative radiotherapy does not seem to affect the final outcome of facial function.

OBJECTIVES

During radical parotidectomy, the sacrifice of the facial nerve results in severe disfigurement of the face. Data on the principles and outcome of facial nerve reconstruction and reanimation after radical parotidectomy are limited and no consensus exists on the best practice.

METHOD

This study retrospectively reviewed all patients having undergone radical parotidectomy and immediate facial nerve reconstruction with a free, non-vascularized nerve graft at the Helsinki University Hospital, Helsinki, Finland during the years 1990-2010. There were 31 patients (18 male; mean age = 54.7 years; range = 30-82) and 23 of them had a sufficient follow-up time.

RESULTS

Facial nerve function recovery was seen in 18 (78%) of the 23 patients with a minimum of 2-year follow-up and adequate reporting available. Only slight facial movement was observed in five (22%), moderate or good movement in nine (39%), and excellent movement in four (17%) patients. Twenty-two (74%) patients received post-operative radiotherapy and 16 (70%) of them had some recovery of facial nerve function. Nineteen (61%) patients needed secondary static reanimation of the face.

Major salivary gland tumors in children — diagnostic and therapeutic difficulties

Major salivary gland tumors are very rare in the developmental period. Confirming tumor changes of the salivary gland requires precise diagnostic imaging involving an ultrasonography scan, computed tomography and magnetic resonance. A needle aspiration biopsy (NAB) of a tumor is of high importance. Excision of the tumor is the main treatment method in the case of parotid gland tumors. Statistical data concerning tumors suggest choosing less invasive methods, which seems very logical in children. The operational methods used in the tumor treatment are: extracapsular excision of a tumor, partial parotidectomy, total parotidectomy, sometimes proceeded with lymphatic nodes operations. Extracapsular excision of a tumor is a noninvasive method chosen because of simplicity and lesser risk of serious complications. This method is reserved only for the cases of benign tumors of the gland. Most authors, however, consider a partial parotidectomy as a method of choice in benign tumor cases and a total parotidectomy in cases of carcinomas of the parotid gland. Submandibular gland tumors need total gland excision. The clinical cases presented in this paper show the difficulties in diagnosis and treatment choices in cases of major salivary gland tumors in children.

Salivary gland carcinomas

INTRODUCTION

Salivary gland carcinomas are rare tumours of heterogeneous morphology that require distinctive surgical and adjuvant therapy.

METHODS

Relevant studies were electronically searched in PubMed and reviewed for innovative and important information.

RESULTS

Recent insights in genetic alterations like chromosomal aberrations, expression of receptor tyrosine kinases, malfunction of tumour suppressor genes or DNA promoter methylations increased the knowledge about aetiology and pathogenesis. New histological subtypes are recognised, and a three-tiered grading system seems reasonable. Ultrasound remains the basic diagnostic imaging procedure. New developments comprise the diffusion-weighed magnetic resonance imaging, while fluorodeoxyglucose positron emission tomography/computed tomography shows good diagnostic accuracy in detecting distant metastases and local recurrence. Fine-needle aspiration cytology helps in differentiating a neoplasia from a non-neoplastic lesion while being unreliable in recognising malignancy. In contrast, additional core needle biopsy and/or intraoperative frozen section diagnosis increase the accuracy in diagnosing a malignant lesion. Conservative parotid surgery with nerve monitoring remains state-of-the-art. Free flaps or musculoaponeurotic flaps are proposed for prevention of Frey's syndrome. As parotid cancer often shows skip metastases, complete ipsilateral neck dissection (level I-V) is indicated particularly in high-grade lesions. Adjuvant radio(chemo)therapy increases local tumour control, whereas overall survival is not necessarily improved. Current results of systemic chemotherapy or targeted therapy in advanced tumour stages are disappointing.

CONCLUSION

Despite several developments, salivary gland carcinomas remain a heterogeneous group of tumours challenging both pathologists and clinicians.

Signs and symptoms of parotid gland carcinoma and their prognostic value

The aim of this study was to analyse signs and symptoms present in patients with parotid gland carcinoma and to assess their prognostic value. A retrospective study of data from 131 patients who were treated surgically was performed. Evaluation of prognostic factors was possible in 109 patients who completed a minimum 5 year follow up. The most common sign and symptoms were parotid mass (96.9%), pain (40.4%), enlarged cervical lymph nodes (32.0%), facial nerve palsy (20.6%) and overlying skin infiltration (19.8%). In 20% of all cases there were no symptoms of tumour malignancy. The average duration of symptoms suggesting malignancy was 4 months. In univariate analysis, the strongest prognostic value was found for facial nerve palsy; it reduced nearly tenfold (9.7) the 5-year disease-free survival. The subsequent poor prognostic factors were: skin infiltration, enlarged cervical lymph nodes, tumour fixation and tumour size (>4 cm). Pain and the dynamics of tumour growth were not statistically significant for survival rate. Significant difference in 5-year disease free survival rate was found between the groups of patients, according to the number of symptoms suggesting malignancy. The multivariate analysis showed that only facial nerve palsy and skin infiltration were independent prognostic factors.

The presence of facial nerve weakness on diagnosis of a parotid gland malignant process

The objectives of this article are to assess the frequency and significance of facial paralysis and undiagnosed nerve infiltration in patients with parotid malignancies. 103 patients with parotid gland malignancies were treated in a single institution, the tertiary center for ENT at the University Department in Poznan between 1996 and 2006. Facial palsy at the initial presentation was found in 32 patients. The stage of the primary tumor in the examined group of 103 patients is as follows: 20—T1, 31—T2, 20—T3, 32—T4. The correlation between facial nerve function before treatment and patients’ characteristics, including the treatment methods, were analyzed. Intact facial nerve function at patient presentation was a very strong prognostic factor determining the treatment and final outcome for malignant neoplasms of parotid gland. Similarly, T stage and a high-grade malignant histology had a direct influence on the duration of patients’ survival.

Are all prognostic factors in parotid gland carcinoma well recognized?

The aim of his study was to assess the treatment results and prognostic factors in patients with parotid gland carcinoma. The material consisted of 109 patients treated surgically, with or without complementary radiotherapy, between 1978 and 2008 (follow-up at least 5-years). 5-year overall and disease-specific survival were observed in 57.0% of the patients and 5-year disease-free survival was achieved in 50.0%. Univariate analysis including ten clinical and pathological features to assess their prognostic value was done. Parapharyngeal space invasion, facial nerve palsy, and high grade of tumor malignancy were the factors with the highest influence on the treatment results, because their presence decreased the chance for recovery 9.8, 9.7, and 8.2 times, respectively. Histologically positive cervical lymph nodes and extraparenchymal extension were the other factors connected with poor prognosis (prognosis worse 6.7 and 5.4 times, respectively). Clinically positive cervical lymph nodes, positive/uncertain microscopic margin, involvement of the deep lobe, or the whole gland increased the risk of treatment failure 3.4, 3.1, and 2.8, respectively. The age ≥60 years and male gender were statistically significant factors, correlated with poor prognosis and decreased chance for recovery 2.4 and 2.6 times. T-status and clinical stage had important influence on 5-year disease-free survival rate because there were significant differences in the treatment results between individual stages. Multivariate analysis proved that the independent prognostic value, among anatomic structures involved by the neoplasm, had mandible, facial nerve, and skin infiltration. Among tumor-related factors, T-stage and grade had the statistically significant influence on treatment results, and stage and lymph nodes metastases among clinical and pathological features. These results confirm the value of actually used TNM classification (2002). Although the parapharyngeal space invasion is a factor, which seems to have a significant, poor prognostic value, it was not included in this classification.

When the bell tolls on Bell's palsy: finding occult malignancy in acute-onset facial paralysis

PURPOSE

This study reports 4 cases of occult parotid malignancy presenting with sudden-onset facial paralysis to demonstrate that failure to regain tone 6 months after onset distinguishes these patients from Bell's palsy patients with delayed recovery and to propose a diagnostic algorithm for this subset of patients.

MATERIALS AND METHODS

A case series of 4 patients with occult parotid malignancies presenting with acute-onset unilateral facial paralysis is reported.

RESULTS

Initial imaging on all 4 patients did not demonstrate a parotid mass. Diagnostic delays ranged from 7 to 36 months from time of onset of facial paralysis to time of diagnosis of parotid malignancy. Additional physical examination findings, especially failure to regain tone, as well as properly protocolled radiologic studies reviewed with dedicated head and neck radiologists, were helpful in arriving at the diagnosis.

CONCLUSION

An algorithm to minimize diagnostic delays in this subset of acute facial paralysis patients is presented. Careful attention to facial tone, in addition to movement, is important in the diagnostic evaluation of acute-onset facial paralysis.

Utility of a herpes oncolytic virus for the detection of neural invasion by cancer

Prostate, pancreatic, and head and neck carcinomas have a high propensity to invade nerves. Surgical resection is a treatment modality for these patients, but it may incur significant deficits. The development of an imaging method able to detect neural invasion (NI) by cancer cells may guide surgical resection and facilitate preservation of normal nerves. We describe an imaging method for the detection of NI using a herpes simplex virus, NV1066, carrying tyrosine kinase and enhanced green fluorescent protein (eGFP). Infection of pancreatic (MiaPaCa2), prostate (PC3 and DU145), and adenoid cystic carcinoma (ACC3) cell lines with NV1066 induced a high expression of eGFP in vitro. An in vivo murine model of NI was established by implanting tumors into the sciatic nerves of nude mice. Nerves were then injected with NV1066, and infection was confirmed by polymerase chain reaction. Positron emission tomography with [(18)F]-2'-fluoro-2'-deoxyarabinofuranosyl-5-ethyluracil performed showed significantly higher uptake in NI than in control animals. Intraoperative fluorescent stereoscopic imaging revealed eGFP signal in NI treated with NV1066. These findings show that NV1066 may be an imaging method to enhance the detection of nerves infiltrated by cancer cells. This method may improve the diagnosis and treatment of patients with neurotrophic cancers by reducing injury to normal nerves and facilitating identification of infiltrated nerves requiring resection.