Malignant Parotid Research Articles

Clinical behaviours and prognoses of high- and low-risk parotid malignancies based on histology.

To report 5-year survival in patients with primary parotid malignant tumours and assess the impact of various factors on survival or local control among diverse histologic groups. A total of 65 patients with primary parotid malignant tumours who had surgery between 2003 and 2014 were identified. Demographic characteristics including age, T stage, N stage and clinical or pathological performance were analysed. According to risk stratification (based on pathology), 65 primary parotid malignant tumours were divided into high-risk (23, 35.38%) and low-risk (35, 53.85%) groups. Overall survival (OS) and disease-free survival (DFS) were recorded by the Kaplan-Meier methods. The 5-year overall survival rate for primary parotid malignant tumours was 70.9%. Patients older than 60years with fixed mass, pain, facial-nerve palsy and high-grade N stage had adverse OS and DFS. Upon multivariable analysis, facial-nerve palsy (HR 24.59; 95% CI 2.338-178.446; P = 0.002) was the only independent predictive factor for OS. Patients with high-risk parotid malignant types were more likely to have tumour pain, facial-nerve palsy (Chi-square test: < 0.0001 and 0.02), lymphatic metastasis and local/regional recurrence (Chi-square test: 0.008 and 0.012). Compared with low-risk parotid carcinoma, tumours with high-risk histological features tend to need aggressive surgical extirpation, neck dissection and postoperative radiotherapy.

Clinicopathological Features and Treatment Outcomes in Parotid Malignancies at Ocean Road Cancer Institute, Dar-es-Salaam, Tanzania

Background: Neoplasms that arise in the salivary glands are relatively rare, yet they represent a wide variety of both benign and malignant histologic subtypes. Tumors of the salivary glands form one of the most heterogeneous groups of oncological pathology. Head and neck tumors represent ∼5% of human neoplasms, and out of these, salivary gland neoplasms constitute 10%. Aim: The challenges faced for parotid gland malignancy are numerous and these factors determine the treatment modality, prognosis and outcome, overall survival, sociodemographic features affecting Tanzanian residents and there is very little knowledge on clinicopathological aspects of parotid gland malignancies diagnosed at a tertiary health center and this study can compare the findings with epidemiologic data from different geographic locations. Methods: A Retrospective study design was used among all patients who had been diagnosed and confirmed histologically with malignant Parotid tumor referred to and treated at Ocean Road Cancer Institute (ORCI) from January 2009-December 2016. Analysis of this retrospective study determined the sociodemographic factors, clinico-pathologic features, treatment outcomes of surgery, radiotherapy, chemotherapy and assessment of 2 years overall survival of parotid malignancies from January 2009 to December 2014. The study was conducted at ORCI in Dar es Salaam. Results: Out of 94 patients with histologically confirmed parotid gland malignancy, more males were affected compared with females with the ratio of 1.18:1 and the mean SD age of patients was 51.9 years. Adenocarcinoma was the most common malignant tumor n = 37 (40%) followed by squamous cell carcinoma n = 18 (19.1%) and the left parotid gland being the most affected site. 44 cases (46.8%) had pathologic grading, grade IV accounting for majority of the grades (27.3%). Stage IV was presented the most n=72 (76.5%) and 8.5% presented with metastasis at diagnosis. 31% of patients were subjected to surgery while 69.1% were deemed to be unfit for surgery due to advanced disease. Radiotherapy was received by n = 82 (95.2%) with 13 patients (14%) subjected to curative intent and 69 patients (86%) subjected to palliative intent. 2 year overall survival for the curative cohort from 2009-2014 is 23% and 11% for the palliative arm. The 2 year overall survival of parotid gland malignancy treated at ORCI is 12%. Conclusion: Clinico-pathologic presentation of parotid gland malignancy seen in this study differs from other studies probably due to geographical variations. More males are affected than women, especially in the middle ages. Adenocarcinoma was the most frequent histology. Two years overall survival from 2009 to 2014 was 12%. Late stage presentation was seen as a problem that needs to addressed to maximize the effectiveness of the treatment, and improve the overall survival. Treatment modalities need to be standardized across health facilities in Tanzania.

Positive surgical margins in parotid malignancies: Institutional variation and survival association.

To establish benchmarks for positive margin incidence in parotid cancers, associate positive margin status with patient, tumor, and institutional factors and overall survival, and characterize institutional variation in positive margin incidence. Retrospective database analysis. We identified patients surgically treated for a parotid malignancy 2004 to 2013 in the National Cancer Database. We associated positive margins with patient, tumor, and treatment factors by multivariable logistic regression and with overall survival by Cox proportional hazards regression. We characterized institutional variation in positive margin rates by facility type and volume. A total of 5,639 patients were identified. The overall positive margin rate was 31%. By institution, positive margin rates varied from 0% to 100%, with a median rate of 31% (interquartile range = 18%-43%). Adenoid cystic carcinoma was associated with increased, and low-grade mucoepidermoid carcinoma with decreased, odds of positive margins, (odds ratio [OR] = 1.91 [95% confidence interval {CI}: 1.54-2.38], P < .001 and OR = 0.68 [95% CI: 0.53-0.87], P = .002, respectively). Treatment at academic or high-volume facilities was associated with decreased odds of positive margins (OR = 0.79 [95% CI: 0.68-0.91], P = .001 and OR = 0.76 [95% CI: 0.63-0.91], P = .004). Positive surgical margins were associated with decreased overall survival (62% vs. 79% 5-year overall survival, hazard ratio [HR] = 1.34 [95% CI: 1.20-1.49], P < .001). Upon stratification by histology, this association was maintained for high-grade, but not low-grade, mucoepidermoid carcinoma (52% vs. 74%, HR = 1.56 [95% CI: 1.31-1.86], P < .001 and 89% versus 91%, HR = 1.05 [95% CI: 0.60-1.83], P = .874, respectively). Tumor and institutional factors are associated with positive surgical margins. Positive margin rates vary substantially between facilities and are less likely at academic and high-volume facilities. Positive surgical margins are associated with decreased overall survival and could be considered quality indicators in parotid malignancies. 2c Laryngoscope, 129:129-137, 2019.

Complex treatment of locally advanced squamous cell carcinoma of the parotid gland and secondary primary melanoma

Primary squamous cell carcinoma of the parotid gland accounts for 0.35% up to 9.8% of all parotid malignancies. In advanced stages, the gold standard is wide excision, lymphadenectomy and postoperative radiotherapy. Furthermore, head and neck cancers have an increased risk of secondary primary tumors development. Case report: A 82-year-old male underwent subtotal parotidectomy with facial nerve preservation for right parotid squamous cell carcinoma, in another department. Due to incomplete resection, 4 months later he presented with locoregional recurrence and cutaneous invasion. The patient underwent total parotidectomy en bloc with facial nerve, part of the external auditory meatus, posterior belly of digastric and part of sternocleidomastoid muscle with modified radical neck dissection, levels I-V. The defect was closed with ipsilateral pectoralis major myocutaneous flap, followed by a temporary lateral tarsorrhaphy after two months. The patient underwent adjuvant radiotherapy. One year after surgery, functional and aesthetic impairment of the facial nerve palsy were corrected: the lower face deficit by an orthodromic temporalis tendon transfer; lagophthalmos by lid loading with gold-weight. Postoperative outcome was satisfactory for the patient, with 3 years of postoperative evolution with no recurrence or metastasis. Concomitantly, the patient developed pT1a secondary primary melanoma on the skin island of the flap, which was excised. Conclusion: Patients with locoregional advanced parotid squamous cell carcinoma can benefit from wide excision with neck dissection and postoperative radiotherapy. When the facial nerve cannot be preserved, facial asymmetry can be improved through reanimation procedures. Secondary primary malignancies require proper treatment concomitantly with index tumor follow-up.

Mucoepidermoid carcinoma of the parotid gland: A National Cancer Database study

ObjectiveTo describe the demographics, tumor characteristics, and prognostic features of mucoepidermoid carcinoma of the parotid gland. Materials and methodsA retrospective study of the National Cancer Database was reviewed for all mucoepidermoid carcinomas of the parotid gland between 2004 and 2012). Patient demographics and tumor characteristics were abstracted and analyzed. Univariate and multivariate Cox multivariate regression models were used to identify predictors of survival. ResultsA total of 4431 patients met inclusion criteria. Average age at diagnosis was 57 years (median 62, SD 19), with no overall sex preference (52% female), and majority white (78%). The 1-year overall survival was 92.9% (95% CI [92.1–93.6]) and 5-year overall survival was 75.2% (95% CI [73.8–76.7%]). Median overall survival was not reached at 5 years. Factors associated with decreased survival were increasing age, comorbidities, high tumor grade, advanced pathologic group stage, and positive surgical margins. Female sex was the only factor associated with improved survival. Controlling for either histopathologic grade or pathologic stage to determine how patient demographics and tumor characteristics affected overall survival yielded similar results. Of note, intermediate grade tumors, although not independently associated with worse survival, when seen in conjunction with tumors ≥T2 and/or ≥N2, a negative impact on overall survival was seen. ConclusionAlthough mucoepidermoid carcinoma of the parotid gland is the most common parotid gland malignancy, it is still a rare tumor with a lack of large population-based studies. Advanced stage and high-grade tumors are significant predictors of decreased survival. Females have improved survival compared to males.

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.

Prognostic factors in parotid cancers: Clinicopathological and treatment factors influencing outcomes.

Parotid cancers are uncommon and have a relatively long natural history. Determination of prognostic factors affecting the outcome is difficult. The primary objective was to determine the demographic, clinical, histopathology and treatment-related factors affecting overall survival (OS) in parotid cancers. The secondary objective was to study the impact of these factors on disease-free survival (DFS) and patterns of failure. Data of consecutive patients who underwent parotidectomy for primary parotid malignancy between July 2006 and April 2015 with at least 6 months of posttreatment follow-up were retrospectively retrieved. Patients whose follow-up status was known at the time of analysis were included. One hundred and sixty-five patients met the inclusion criteria. The median follow-up was 38 months. The mean OS and DFS were 141.03 and 124.38 months, respectively. Age > 45 years affected both OS and DFS (P = 0.00 and 0.002 respectively) adversely. Advanced T stage affected adversely OS in univariate (P = 0.00) but not in multivariate analysis (P = 0.91) and DFS in both univariate (P = 0.00) and multivariate analysis (P = 0.005). Nodal positivity adversely affected survival adversely in univariate (P = 0.00 for OS and DFS) and multivariate analysis (P = 0.022 for OS and P = 0.001 for DFS). Resection margin of < 5mm affected OS as compared to a margin of ≥5mm (P = 0.03). Nodal positivity is the single most important factor affecting survival in parotid cancers. A histopathological resection margin of at least 5 mm is desirable. Advanced age along with high grade, advanced T and N stages need to be considered for adjuvant treatment.

Free gracilis muscle transfer for smile reanimation after treatment for advanced parotid malignancy.

The purpose of this study was to characterize the outcomes of free gracilis muscle transfer for delayed smile reanimation after radical parotidectomy. A retrospective chart review of patients who underwent free gracilis muscle transfer for smile reanimation after radical parotidectomy between 2003 and 2016 was performed. Patient-reported quality of life (Facial Clinimetric Evaluation Scale [FaCE]), physician-reported facial function ("eFACE" facial grading scale), and oral commissure excursion were compared preoperatively and postoperatively. Twelve patients were identified with prior surgery and adjuvant therapy (radiotherapy in 6 cases and chemoradiotherapy in 6 cases). Significant postoperative improvements were demonstrated for ipsilateral commissure excursion with smile (preoperatively: -2.2 mm [SD 2.3 mm] vs postoperatively: 7.9 mm [SD 2.5 mm]; P = .002), with meaningful smile achieved in 11 of 12 cases (91.7%). The average duration of facial paralysis before intervention was 72 months (range 12-204 months). Free gracilis muscle transfer is an option for dynamic smile reanimation in select patients who have undergone treatment for advanced parotid malignancy.

Accuracy of preoperative fine needle aspiration in diagnosis of malignant parotid tumors.

Objectives:To determine the diagnostic accuracy of fine needle aspiration (FNA) for detecting malignant parotid tumors.Methods:We conducted a retrospective study of all patients diagnosed with benign or malignant parotid gland tumors in King Abdulaziz University Hospital, Jeddah, Saudi Arabia, between January 2004 and May 2015. The records of 65 subjects were obtained. Histopathological findings and data from FNA examinations were obtained from medical records. Twenty-three subjects were excluded due to missing FNA, histopathology results or both. The sensitivity, specificity, negative predictive value, and positive predictive value of FNA for detecting malignant lesions were estimated and compared with the gold standard, histopathology.Results:The specimens of 5 cases were insufficient for diagnosis; therefore, 38 cases were diagnosed by FNA and had histopathological reports. Three cases were diagnosed positive for cancer using histopathology and missed by FNA, 3 were diagnosed as malignant lesions using both FNA and histopathology, and 32 cases were determined benign based on histopathology and FNA analysis. The total prevalence of parotid malignancies was 15.8%. The sensitivity of FNA for detecting malignancy was 50%, and the specificity was 100%; with a positive predictive value of 100% and negative predictive value of 91.4%.Conclusion:Fine needle aspiration is a highly specific, but only moderately sensitive test. We support the use of this method as an initial tool for diagnosing parotid gland malignancies, as it is a safe, rapid, and painless procedure, compared to histopathology.

Incidence of facial nerve sacrifice in parotidectomy for primary and metastatic malignancies

IntroductionThe parotid gland may become involved by primary parotid malignancies and secondarily by metastases from other primary sites. Surgical resection of these tumors can be technically challenging due to the intimate relationship of the parotid gland and the facial nerve. The primary aim of this project was to determine the incidence of facial nerve sacrifice in parotidectomy for primary and secondary malignancies of the parotid. MethodsA retrospective chart review of was performed. Patients who received parotidectomy with final pathology consistent with a malignant neoplasm were included. The primary outcome studied was necessity for facial nerve sacrifice. Co-variates included preoperative facial nerve function, preoperative pain, superficial versus total parotidectomy and pathologic diagnosis. Univariate analysis was performed using student t-test to determine odds ratios. ResultsWe identified 75 patients who had a parotidectomy for a malignant process in our review. 30 patients had facial nerve sacrifice: 14 total and 16 partial sacrifices. Patients were more likely to require facial nerve sacrifice when they presented with preoperative facial nerve dysfunction [100% vs 19.6%, p=0.0006, OR 154.3, CI (8.66–2750.9)], pre-op pain [76.5% vs. 29.3%, p=0.001, OR 7.84, CI (2.23–27.50)], and required excision of both superficial and deep lobes of the parotid gland [64.9% vs 15.8%, p=0.0001, OR 9.85, CI (3.27–29.66)]. ConclusionOur data illustrates that many patients with normal facial nerve function, even in the setting of malignancy, can have their facial nerve preserved. Pain, deep lobe involvement and preoperative facial nerve dysfunction are associated with an increased risk of needing at least partial facial nerve sacrifice in the setting of parotid gland malignancies.

Metastatic cutaneous squamous cell carcinoma of the parotid gland: prognostic factors.

Metastatic cutaneous squamous cell carcinoma is the most common parotid malignancy in Australasia. Prognostic indicators are not clearly defined and the extent of surgical resection required is controversial. A retrospective analysis was conducted of 63 patients who underwent surgery for metastatic cutaneous squamous cell carcinoma of the parotid gland at a tertiary hospital over a 10-year period. The five-year overall survival rate was 53 per cent, the disease-specific survival rate was 78 per cent and the locoregional control rate was 72 per cent. Immunosuppression and no adjuvant radiotherapy were associated with a significant reduction in disease-specific survival. None of the factors analysed had a significant effect on locoregional control rates. More extensive surgery, including lateral temporal bone resection, may improve local control rates in cases of more advanced disease. The reduced survival of immunocompromised patients must be considered when planning their management.

(P078) Radiotherapy for Parotid Malignancies: Patterns of Care and Impact on Overall Survival

(P078) Radiotherapy for Parotid Malignancies: Patterns of Care and Impact on Overall Survival

Treatment of locally advanced parotid malignancies with parotidectomy and temporal bone resection

PurposeIn this study we review our institution's experience and outcomes with temporal bone resection and parotidectomy in the treatment of advanced parotid malignancies. MethodsPatients undergoing lateral temporal bone resection and parotidectomy from 2007–2013 were identified in the EPIC electronic medical record. Primary tumor location, staging, surgical procedure, and patient demographic and outcome data were collected retrospectively. ResultsFifteen patients underwent combined temporal bone resection and parotidectomy for parotid malignancy. Carcinoma ex-pleomorphic and squamous cell carcinoma were the most common pathologies. Two year disease free survival was 40%. Distant metastases were the most common site of disease recurrence. Only nodal disease was predictive of reduced disease free survival, though pre-operative facial paralysis showed a trend towards significance. Margin status and operating for recurrent tumor did not influence outcome in our series. ConclusionLocal and regional tumor controls are attainable with combined skull base approaches to advanced parotid malignancies. Unfortunately these cases have a high rate of distant recurrence despite negative margins and local control.

Diffusion-weighted MRI in the differential diagnosis of parotid malignancies and pleomorphic adenomas: can the accuracy of dynamic MRI be enhanced?

(1) To verify whether appropriate selection of cutoff values for dynamic and diffusion-weighted magnetic resonance imaging (MRI) parameters optimizes the accuracy of preoperative differential diagnosis of parotid malignancies and pleomorphic adenomas. (2) To define the role of preoperative MRI in the differential diagnosis of parotid tumors. The retrospective analysis included 221 surgical patients with parotid tumors. Aside from ultrasonography-guided fine-needle biopsy, the preoperative protocol included dynamic and diffusion-weighted MRI. Final diagnoses were based on histopathologic examination of surgical specimens. Receiver operating characteristic analysis was conducted to determine the sensitivity and specificity of preoperative MRI with various combinations of cutoff values. Twenty-four patients with parotid malignancies (10.8%) and 57 with pleomorphic adenomas (25.8%) were identified. Parotid malignancies had significantly lower values of apparent diffusion coefficient and Tpeak, as well as significantly higher values of Tmax and washout rate. An apparent diffusion coefficient ≤1.267×103mm/s2 yielded optimum accuracy in identification of parotid malignancies (95.8% sensitivity and 93% specificity). Diffusion-weighted MRI is effective in differential diagnosis of parotid malignancies. Optimization of preoperative diagnosis of parotid tumors should include preselection identification of Warthin tumors on the basis of dynamic MRI, followed by identification of pleomorphic adenomas based on diffusion-weighted MRI and cytologic examination of the remaining lesions.

Extracapsular dissection as sole therapy for small low-grade malignant tumors of the parotid gland.

The aim of the study was to investigate whether extracapsular dissection of a primarily unsuspected lesion in the parotid gland could be oncologically sufficient for carefully selected cases of parotid gland malignomas. Retrospective clinical study. The records of all patients treated for primary malignant tumors of the parotid gland solely by means of extracapsular dissection between 2006 and 2013 were studied retrospectively. Patients with manifestation of malignant tumors in the parotid gland that were not of primary salivary gland origin (squamous cell carcinomas, lymphomas, melanomas) or who had had revision surgery or other malignant tumors in their history, as well as patients with insufficient data, were excluded from our study sample. Nine patients, all with low-grade parotid malignancies, were detected. Our study showed acceptable oncologic and functional outcomes throughout. Our study was able to show very encouraging preliminary results following primary extracapsular dissection as sole surgical therapy for carefully selected low-stage, low-grade, inferiorly located lesions in patients with high compliance. 4. Laryngoscope, 127:1804-1807, 2017.

Kimura’s Disease- A Diagnostic Challenge

Kimura’s disease is a rare, benign, chronic inflammatory disease with an unknown etiology, which predominantly affects Asian males. It has predilection for the head and neck region, and primarily involves the major salivary glands and is accompanied with loco-regional lymphadenopathy. It is therefore often misdiagnosed for a salivary gland tumor or lymphadenopathy secondary to metastases, lymphoma or tuberculosis. We present a case of Kimura’s disease in a middle aged Chinese male patient manifesting as painless lumps over the left jaw and neck. Based on the CT scan, the differential diagnoses of lymphomatous/metastatic adenopathy affecting the left cervical and parotid nodes or a primary left parotid malignancy with ipsilateral metastatic adenopathy were considered. However, a fine needle aspiration biopsy of the left sided adenopathy yielded the diagnosis of Kimura’s disease. The triad of subcutaneous masses in head and neck region, regional lymphadenopathy and masses in one or more of the major salivary glands should raise the suspicion of Kimura’s disease.

Tuberculous Lymphadenitis and Parotitis.

Tuberculous lymphadenitis is the most common extrapulmonary manifestation of disseminated tuberculosis (TB). It is considered to be the local manifestation of the systemic disease that has disseminated to local lymph nodes, but a high index of suspicion is needed for the diagnosis, because there are several infectious and noninfectious diseases that can mimic the same clinical picture. In recent years, different diagnostic methods have been introduced, including fine-needle aspiration cytology, which has emerged as a simple outpatient diagnostic procedure that replaced the complete excisional node biopsy, and a number of molecular methods which have greatly improved diagnostic accuracy. This chapter covers the most actual knowledge in terms of epidemiology, clinical manifestations, pathogenesis, and treatment and emphasizes current trends in diagnosis of tuberculous lymphadenitis. TB parotid gland involvement is extremely rare, even in countries in which TB is endemic. Because of the clinical similarity, parotid malignancy and other forms of parotid inflammatory disease always take priority over the rarely encountered TB parotitis when it comes to differential diagnosis. As a result, clinicians often fail to make a timely diagnosis of TB parotitis when facing a patient with a slowly growing parotid lump. This chapter highlights the most important features of this uncommon disease.

Accuracy of Fine Needle Aspiration Biopsy in Diagnosing Parotid Gland Malignancy

Objective: To determine the sensitivity, specificity, positive predictive value, negative predictive value and overall accuracy of FNAB in detecting parotid malignancies in our institution.&#x0D; Methods: &#x0D; Design: Retrospective Chart Review&#x0D; Setting: Tertiary Government Hospital&#x0D; Participants: Postoperative records of seventy six (76) patients with tumors of the parotid gland preoperatively diagnosed by FNAB.&#x0D; Results: The sensitivity of FNAB was 46%. The specificity and positive predictive value were both 100% and negative predictive value was 90%. Overall accuracy in diagnosing malignant parotid tumor was 91%.&#x0D; Conclusion: FNAB in this institution is a poor predictor of malignancy, having a sensitivity rate of only 46%. While this may serve as a basis for not recommending pre-operative FNAB for patients with parotid tumors in the interim, other factors should also be considered, including concerns with the actual performance and interpretion of FNAB in our institution.&#x0D; Keywords: Parotid neoplasm, Cancer of the parotid, fine needle aspiration biopsy, sensitivity, specificity, accuracy

Parotid malignancies are not homogenous in terms of their presentation on dynamic MRI – a preliminary report

Conclusion: At least two groups of parotid malignancies exist, including one whose parameters of dynamic MRI closely resemble those of pleomorphic adenomas. Also tumors with long time to peak enhancement after administration of a contrast agent (Tpeak) and low washout rate (WR) should be considered malignant, especially single masses with concomitant lymphadenopathy located within the deep parotid lobe.Objective: To verify if malignant tumors of the parotid are homogeneous in terms of parameters of preoperative dynamic MRI: Tpeak and WR.Methods: The retrospective analysis included 221 surgical patients with parotid tumors. Aside from fine needle biopsy, pre-operative examination included dynamic and diffusion-weighted MRI. Final diagnosis was based on histopathological examination of the surgical specimen.Results: Twenty-four of 221 (10.8%) malignant lesions were identified. Using k-means clustering based on Tpeak and WR values, two distinct clusters of parotid malignancies were identified. The cut-off value for Tpeak optimally differentiating between the clusters was 140 s; the cut-off value for WR could not be identified. The two clusters did not differ in terms of dynamic and diffusion-weighted MRI parameters, patient age, sex and prevalence of lymphadenopathy. Significant inter-cluster differences were found in the prevalence of deep parotid lobe involvement and presence of a single mass.

Focal fluorine-18 fluorodeoxyglucose-avid parotid findings in patients with lung cancer: prevalence and characteristics.

Correct interpretation of incidental tumors is important to plan an appropriate treatment. We assessed the incidence and imaging characteristics of fluorine-18 fluorodeoxyglucose (F-FDG)-avid focal parotid findings (FPFs) in patients with lung cancer. FPFs in PET-computed tomography reports of cancer patients were searched. Those with known parotid malignancies, lymphoma, and diffuse F-FDG uptake in the entire parotid gland were not included in the analysis. FPFs were detected in 38/3120 cancer patients (1.23%), observed as a soft tissue mass with a mean diameter 1.6±0.5 cm (range 0.8-2.7 cm) and a mean maximum standardized uptake value of 7.7±3.7 (range 2.5-17.8). FPFs were observed in 23/604 (3.8%) patients with lung cancer, compared with 6/1366 (0.4%) with breast cancer and 5/842 (0.6%) with gastrointestinal malignancies. We assessed FPFs appearances in 23 patients with lung cancer (18 men, mean age 72.8±9.2); 20 (87%) were current or past smokers. There was no correlation between the stage or histopathological type of the lung cancer and the prevalence of parotid lesions. In four patients with histopathology, no malignancy was detected. For an additional 11 patients with available imaging and clinical follow-up (mean follow-up 15.5±13.5 months, range 3-42 months), FPFs were consistent with benign lesions. FPFs were more prevalent among patients with lung cancer than in patients with other malignancies. As F-FDG avidity was moderate to high, FPFs may mimic distant metastases. It is important to consider FPFs in the interpretation of a focal parotid lesion as misinterpretation may result in denial of appropriate therapy.