Malignant Parotid Gland Tumors Research Articles

CT features and analysis for misdiagnosis of parotid tuberculosis

PurposeTo analyze the computed tomography (CT) features and the reasons for misdiagnosis of parotid tuberculosis (TB). MethodsCT features of 13 cases of parotid TB identified more than a 10-year period (2005–2015) were retrospectively analyzed. The CT features were analyzed for nature, range, and extent of the various pathological patterns. ResultsBecause of the nonspecific CT features, 10 of 13 cases were misdiagnosed as benign and malignant tumors of parotid gland and received surgery. Ten cases of lymph nodal TB, one case of parenchymal TB, and two cases of mixed (concurrence of lymph nodal and parenchymal types) TB were found in the parotid gland. On contrast-enhanced CT scan, two cases showed homogeneous enhancement and eight cases showed ring enhancement (including five cases with thin-walled ring enhancement, two cases with flower-ring enhancement, and one case with thick-walled and eccentric ring enhancement); diffuse enhancement was seen in the one case of parenchymal type; the two cases of mixed type showed diffuse enhancement of parotid gland and ring enhancement of lymph node. Thickened skin around the parotid gland was seen in eight cases, including sinus tract between the lesion and skin in two cases. Ipsilateral cervical lymphadenopathy was found in 10 patients and bilateral was found in 3 patients. ConclusionsNonspecific CT features of parotid TB closely relate with pathological changes. Recognition and understanding the spectrum of CT features of parotid TB is helpful for differential diagnosis, but the definitive diagnosis still depends on laboratory and pathological examination.

Diagnostic value of metabolic heterogeneity as a reliable parameter for differentiating malignant parotid gland tumors.

Exact classifying between malignant and benign tumors in the parotid gland is important because the cancer has relatively poor prognosis. There have been several studies that F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) can differentiate between malignant and benign parotid gland tumors. However, the role of FDG PET is still controversial because many benign parotid gland tumors, such as Warthin's tumor and pleomorphic adenoma, show high FDG uptake. We hypothesized that metabolic heterogeneity would differentiate malignant parotid tumors because tumoral heterogeneity is an important characteristic in the malignancies. From January 2010 to April 2015, we retrospectively reviewed the 46 patients who showed FDG uptake at the parotid gland. To differentiate malignant parotid gland tumors, we obtained maximum SUV and mean SUV. Metabolic tumor volume and total lesion glycolysis were measured as metabolic volumetric parameters. We also included heterogeneity parameters of FDG PET such as heterogeneity factor (HF) and the coefficient of variation for all patients. There was significant difference of HF between malignant (-0.30±0.25; range -0.937 to -0.084) and benign parotid gland tumors (-0.06±0.05; range -0.291 to -0.012; p<0.0001). In receiver operating characteristic analysis, when ≤-0.084 was used as the cut-off value for HF, the sensitivity and specificity were 100% (95% CI 81.5-100) and 89.2% (95% CI 71.8-97.7), respectively. HF showed the highest area under the curve of 0.947 among the parameters. In logistic regression analysis, the HF was the most powerful factor for differentiation of the parotid gland tumors (p=0.002). Our results suggest that HF can be utilized as a reliable and non-invasive method for differentiation of malignant and benign parotid gland tumors.

Parotid gland tumours in Turkish population: analysis of 165 patients.

Retrospective data on 165 patients who presented with a parotid mass and underwent surgery in our clinics during 2000-2009 were examined. The obtained data (demographic data, surgical procedures, histopathological diagnoses) were compared to similar studies to make contributions to the literature. Patients were classified according to their histopathological diagnosis. Surgical procedures and patient follow-up were clarified. The results are presented as means and standard deviations. Of the 165 masses, 134 (81.3%) were benign and 31 (18.7%) were malignant. Pleomorphic adenoma was the most common benign tumour (79 patients, 59%). Lymphoma and adenoid cystic carcinoma were equally common and were the most common malignant parotid gland tumours (both 6 patients, 19.3%). The most frequent surgical procedure was superficial parotidectomy (92 patients, 55.7%), and the most commonly encountered surgical complication was facial paralysis (12 patients, 7.2%). Our data are generally in line with the literature but lymphoma was more common than in most previous reports. Although the number of cases was low, the high incidence of parotid gland lymphoma was remarkable.

A Rare Presentation of Carcinosarcoma in a Long Standing Parotid Mass

A Rare Presentation of Carcinosarcoma in a Long Standing Parotid Mass Introduction: Parotid tumours represent one of common tumours seen in the field of Otorrhinolaryngology. Common benign tumours include pleomorphic adenoma and warthins tumour while most common malignant parotid gland tumour is mucoepidermoid carcinoma. This case, however, highlights a rare parotid tumour in a long standing parotid mass. Objective: To present a rare case of parotid carcinosarcoma ex pleomorphic adenoma. Clinical Report: A 35 year old Malay gentleman with no prior medical illness first presented on 22nd October 2013 with history of left parotid swelling for more than 10 years in which he had not seeked treatment before. He was compelled to seek treatment after a drastic increase in size within 2 weeks prior to swelling. Patient has been an active smoker past 20 years. Examination revealed a large, lobulated left parotid mass measuring 10 cm x 9 cm x 8 cm which was hard, not tender and fixed to overlying skin. There were no palpable neck nodes and facial nerve was intact. Fine needle aspiration cytology revealed mucoepidermoid carcinoma ex pleomorphic adenoma. He underwent tracheostomy, left extended total parotidectomy, left supraomohyoid neck dissection with soft tissue reconstruction with free fasciocutaneous anterolateral thigh (ALT) flap on 11th March 2014. Histopathological examination of the parotid mass revealed carcinosarcoma ex pleomorphic adenoma. Conclusion: This case report highlights a rare malignant transformation of a long standing parotid mass to form carcinosarcoma of the parotid gland.

Paediatric parotid neoplasms: a 10 year retrospective imaging and pathology review of these rare tumours

To determine the relative incidence of benign and malignant paediatric parotid gland tumours and whether particular presenting symptoms or imaging characteristics were more likely to predict malignancy. Hospital records were reviewed for all patients <18 years with histopathology-proven parotid neoplasms over the 10 year period from 2003-2013. Infantile haemangiomas and patients with neurofibromatosis type I were excluded. The presenting clinical symptoms for each patient were recorded. All available CT and MRI examinations for these patients were evaluated for tumour imaging characteristics. Seventeen patients (nine boys, eight girls; age range 2-17 years) were identified with neoplastic parotid masses; 11 tumours were malignant (65%) and six were benign (35%). The malignant tumours consisted of three acinic cell carcinomas, two mucoepidermoid carcinomas, one alveolar rhabdomyosarcoma, one poorly differentiated carcinoma, one low-grade adenocarcinoma, and three metastases (two melanoma, one orbital medulloepithelioma). The benign tumours consisted of five pleomorphic adenomas and one schwannoma. Presenting clinical symptoms were similar between benign and malignant tumours. Twelve MRI and six CT examinations were available for review with five patients undergoing both techniques. MRI features commonly identified with malignant tumours included: hypointense T2 signal, restricted diffusion, ill-defined borders, and focal necrosis. Only four of the six tumours imaged at CT were visualized, and of those, the margins were indeterminate in three patients. Paediatric parotid masses are more likely to be malignant than benign. Presenting clinical symptoms and CT are not helpful for distinguishing benign and malignant disease. MRI features such as T2 hypointensity, restricted diffusion, ill-defined borders, and focal necrosis, although not specific, should raise concern for malignancy.

Expression and clinical implications of P53, P63, and P73 protein in malignant tumor of the parotid gland.

To investigate the expression of P53, P63, and P73 proteins in malignant parotid gland tumors and adjacent nonneoplastic tissues and the association between the 3 proteins and their clinical characteristics. A total of 40 pairs of paraffin-embedded malignant parotid gland tumors and adjacent nonneoplastic tissues were collected. We detected P53, P63, and P73 protein expression by immunohistochemistry. Statistical analysis was performed by using the chi-square test. P53, P63, and P73 protein expression in malignant parotid gland tumors was higher than their expression in adjacent nonneoplastic tissue (P = 0.030, 0.001, and 0.001, respectively). Expression of P53, P63, and P73 proteins was not associated with age, sex, or lymph node metastasis (P > 0.05). Expression of P53 and P73 proteins, instead of the P63 protein, was correlated to the degree of malignancy (P = 0.026 and 0.018, respectively). There was no significant difference among the P53, P73, and P63 proteins in malignant parotid gland tumors (P > 0.05). In the follow-up, only one patient died of colon cancer. Our results suggest that the P53, P63, and P73 proteins may play a role in the development of malignant parotid gland tumors and provide data for their diagnosis.

Postoperative radiation therapy for parotid mucoepidermoid carcinoma.

Salivary gland cancers are rare and represent approximately 5% of all head and neck cancers and only 0.3% of all malignancies. The majority (75%) of salivary gland tumors occur in the parotid gland, and while benign lesions are more common, mucoepidermoid carcinoma (MEC) makes up 40–50% of malignant parotid gland tumors. No randomized controlled trials exist regarding the role of adjuvant radiation for patients who undergo surgical resection of low-grade MECs. Herein, we report two cases of successful postoperative radiation therapy in low-grade, pT2N0 MEC of the parotid gland. The role of adjuvant radiation therapy for patients with MEC of the parotid gland is based on data from institution reviews and lacks data from randomized controlled trials. Per our review of the literature, the pathological findings of positive surgical margins and/or perineural invasion in two patients with low-grade MEC of the parotid gland warranted adjuvant radiation for improved local control after partial parotidectomy. Both patients tolerated postoperative radiation therapy with only mild side effects and, at last follow-up, five years after completion of therapy, had no clinical or radiographic evidence of either local recurrence or distant metastasis.

A Rare Presentation of Carcinosarcoma in a Long Standing Parotid Mass

A Rare Presentation of Carcinosarcoma in a Long Standing Parotid Mass Introduction: Parotid tumours represent one of common tumours seen in the field of Otorrhinolaryngology. Common benign tumours include pleomorphic adenoma and warthins tumour while most common malignant parotid gland tumour is mucoepidermoid carcinoma. This case, however, highlights a rare parotid tumour in a long standing parotid mass. Objective: To present a rare case of parotid carcinosarcoma ex pleomorphic adenoma. Clinical Report: A 35 year old Malay gentleman with no prior medical illness first presented on 22nd October 2013 with history of left parotid swelling for more than 10 years in which he had not seeked treatment before. He was compelled to seek treatment after a drastic increase in size within 2 weeks prior to swelling. Patient has been an active smoker past 20 years. Examination revealed a large, lobulated left parotid mass measuring 10 cm x 9 cm x 8 cm which was hard, not tender and fixed to overlying skin. There were no palpable neck nodes and facial nerve was intact. Fine needle aspiration cytology revealed mucoepidermoid carcinoma ex pleomorphic adenoma. He underwent tracheostomy, left extended total parotidectomy, left supraomohyoid neck dissection with soft tissue reconstruction with free fasciocutaneous anterolateral thigh (ALT) flap on 11th March 2014. Histopathological examination of the parotid mass revealed carcinosarcoma ex pleomorphic adenoma. Conclusion: This case report highlights a rare malignant transformation of a long standing parotid mass to form carcinosarcoma of the parotid gland.

Malignant Tumors of the Parotid Gland in Children

Population-based analysis of the incidence, demographics, and management outcomes in children with malignant tumors of the parotid gland. Surveillance, Epidemiology, and End Results database (1973-2009) was researched for all patients younger than 20 years. Overall, 284 patients were identified. Annual incidence of these tumors was 1.43 cases per million. The highest incidence occurred in girls (0.86/1,000,000), black children (0.849/1,000,000), and adolescents (1.56/1,000,000). Median age at diagnosis was 13.5 years. Most patients were 10 years or older (n = 256, 90%). Most patients presented with local disease (n = 207, 76%). Only 3% had metastasis at time of diagnosis. Most tumors were mucoepidermoid carcinomas (n = 139, 49%) or acinar cell carcinomas (n = 113, 40%). There were no differences in survival between mucoepidermoid and acinar cell carcinomas (96% vs 98% respectively, P = 0.317). Overall mortality was 4.6% over the study period. Overall survival was 96% at 5 years, 95% at 10 years, and 83% at 20 years. Adolescents had significantly higher mortality rates (7.1% vs 1.6% for children <15 years of age, P = 0.23). Multivariate analysis identified the use of adjuvant radiation therapy (hazard ratio, 6.01; 95% confidence interval, 1.15-31.45; P = 0.034) as the only independent predictor of poor outcome. Malignant parotid gland tumors are most common in adolescents, and this subgroup has worse outcomes. The role of radiotherapy remains controversial.

Comparison of TNM-based stage grouping versus UICC/AJCC stage grouping (7th edition) in malignant parotid gland tumors

Although the UICC/AJCC's TNM staging of the 7th edition was improved in 2002, there are still shortcomings concerning the prognostic quality. Alternative TNM-based stage-groupings such as the T and N Integer Score (TANIS) where shown to have a better prognostic quality for various kinds of head and neck tumors in the past. The aim of the study was to compare the prognostic value of the 7th edition of the UICC/AJCC TNM-classification for carcinoma of the parotid gland with different TNM-based stage groupings. The retrospective analysis included 180 patients with carcinoma of the parotid gland diagnosed between 1986 and 2007. The stage grouping system of the 7th edition of the UICC/AJCC and TNM-based stage-groupings (TANIS-3, TANIS-8, Snyderman, Berg and Hart) were tested for their prognostic significance. Overall survival (OS) was plotted by Kaplan-Meier analysis. Prognostic factors were identified through univariate and multivariate analysis. In univariate analysis all stage-groupings had a highly significant impact on overall survival (p<0.05), however in multivariate analysis, only the TANIS-8 scheme (p=0.008) and Snyderman scheme (p=0.047) predicted OS, while the UICC/AJCC-classification did not predict OS significantly (p=0.381). In comparison to other TNM-based stage groupings the UICC/AJCC-classification did not provide significant prediction of OS, while alternative stage-groupings such as the TANIS-8 had a higher prognostic value.

Discovery and Prevalidation of Salivary Extracellular microRNA Biomarkers Panel for the Noninvasive Detection of Benign and Malignant Parotid Gland Tumors

This study was conducted to explore the differences in salivary microRNA (miRNA) profiles between patients with malignant or benign parotid gland tumors as a potential preoperative diagnostic tool of tumors in the salivary glands. Whole saliva samples from patients with malignant (n = 38) or benign (n = 29) parotid gland tumors were obtained from the Salivary Gland Tumor Biorepository (SGTB). After total RNA isolation, human miRNA cards were used for miRNA profiling. The differential miRNA expression was analyzed using two-sided Wilcoxon test. Quantitative real-time PCR (qRT-PCR) was used to validate selected miRNAs in an independent sample set. Receiver-operating characteristics curve and probability of malignancy was exploited to evaluate the diagnostic power of the validated miRNAs. With miRNA profiling, 57 of 750 investigated miRNAs were differently expressed, of which 54 showed higher miRNA expression in samples from patients with malignant tumors than those from patients with benign tumors. Validating the expression in an independent sample set of 9 miRNAs revealed indeed higher expression of miRNAs in malignant samples compared with benign samples. The expression of 6 validated miRNAs was statistically significantly different between the two groups (P < 0.05). A four miRNA combination was able to discriminate between saliva samples from patients with malignant tumors from those of patients with benign parotid gland tumors (sensitivity 69%, specificity 95%). Salivary miRNA profiles differ in saliva from patients with malignant from saliva from patients with a benign parotid gland tumor. These preliminary results are promising to develop a noninvasive diagnostic tool for diagnosing tumors in the salivary glands.

Diagnostic value of gadolinium-enhanced dynamic MR imaging for parotid gland tumors

ObjectiveThis study aimed to evaluate the value of gadolinium-enhanced dynamic MR imaging for differentiating benign and malignant parotid gland tumors, and for characterizing the various histological types. Patients and methodsNon-enhanced T1-weighted (T1-W), fat-suppressed T2-weighted (T2-W), and gadolinium-enhanced fat-suppressed dynamic T1-weighted images were obtained preoperatively in 27 patients (28 parotid gland tumors), by using a 1.5 or 3 T MR imaging unit (GE, Signa Exite). The tumor margins and the enhancement curve patterns on dynamic MR imaging were analyzed. All patients underwent a parotidectomy with histopathologic analysis. ResultsPleomorphic adenomas depict a gradual enhancement pattern. Warthin’s tumors depict an early peak of enhancement and a high washout pattern. Malignant tumors depict an early peak of enhancement and a low washout pattern. ConclusionGadolinium-enhanced dynamic MR imaging improved the performance of MR imaging in differentiating benign from malignant parotid gland tumors and characterizing the different histological types of benign tumors.

Parotid gland tumors: Correlation between routine cytology and cytomorphometry by digital image analysis using conventional and newly introduced cytomorphometric parameters

The objective of this study was to compare qualitative cytomorphology and morphometric characteristics of parotid gland tumor cells, with the aid of a computer-assisted system of image analysis. Routine qualitative cytologic and quantitative morphometric results from 64 parotid gland tumors were compared. Ultrasound (US)-guided fine-needle aspiration (FNA) specimens were taken from 54 patients. Eleven conventionally used morphometric parameters were studied: area, perimeter, convex area, convexity, maximal and minimal radius, length, breadth, form factor (FF), elongation factor, and nuclear- cytoplasmatic (N/C) ratio. Two newly introduced nuclear form factors were also measured: area symmetry factor and perimeter symmetry factor. The following nuclear morphometric parameters were significantly different between malignant and benign tumors: area, perimeter, convex area, convexity, maximal and minimal radius, length, breadth, FF, elongation factor, area symmetry factor, and perimeter symmetry factor. Comparing the cutoff values and receiver operating characteristic (ROC) curves the following nuclear morphometric parameters were found most useful in separating benign from malignant tumors: area, perimeter, convex area, maximal radius, length, and FF. The following whole cell morphometric parameters were significantly different between malignant and benign tumors: minimal and maximal radius, convexity, breadth, FF, and elongation factor. N/C ratio was significantly higher in malignant tumors. The quantitative morphometric analysis is a useful tool in the cytological differentiation between benign and malignant parotid gland tumors. Computerized image analysis may add to morphological evaluation by turning qualitative data into quantitative values.

副耳下腺腫瘍の臨床的検討

Accessory parotid gland tumors are relatively rare; hence, adequately detailed clinical analyses of these tumors are difficult to perform at a single institution. In this report, we describe the findings for 65 patients [29 men, 36 women; median age, 51 (9-81) years] with accessory parotid gland tumors, consisting of 4 cases documented by us and 61 cases previously reported by other Japanese authors. Approximately 50% of the patients were treated in an otolaryngology department, while the remaining patients were treated in plastic surgery, oral surgery, or dermatology departments. In 4 patients, the results of preoperative fine-needle aspiration cytology indicated that the tumor was benign; however, the postoperative histopathology results revealed malignant tumors. The frequencies of malignant and benign tumors were 44.6% (n = 29) and 55.4% (n = 36), respectively. Mucoepidermoid carcinoma and pleomorphic adenoma were the most frequent types of malignant and benign accessory parotid gland tumors, respectively. Among the various surgical methods that were used, such as direct cheek and intraoral incisions, a standard parotidectomy incision was the most preferred treatment approach for these tumors. Recently, an endoscopic approach has also been found to yield satisfactory results. An optimal approach should be selected after evaluating the advantages and disadvantages of these methods. No definite guidelines are available regarding the choice of elective neck dissection and postoperative radiation therapy for malignant accessory parotid gland tumors. Although tumor resection (plus elective neck dissection) and postoperative radiation therapy have been frequently performed for various kinds of malignant accessory parotid gland tumors to date, additional studies are needed regarding the criteria for selecting elective neck dissection and postoperative radiation therapy. Since the malignancy rate for accessory parotid gland tumors is higher than that for parotid gland tumors, the possibility of malignancy (especially mucoepidermoid carcinoma and carcinoma ex pleomorphic adenoma) should be considered when resecting accessory parotid gland tumors, even if the results of preoperative fine-needle aspiration cytology indicate that the tumor is benign.

Zabiegi rekonstrukcyjne w wielkich guzach gruczołów ślinowych

ObjectiveEvaluation the outcome after extensive surgery of salivary glands tumors with simultaneous reconstruction of soft tissue and skin defect. MaterialIn the period 2007–2011, surgery treatments performed in 295 of major salivary glands. 31 patients underwent surgery due to malignant parotid gland tumors: 19 women (61%) and 12 men (39%). In 8 (26%) presented skin infiltration. 10 (32%) patients had facial palsy between II-IV degree (House Brackmann scale). The radiographic findings in some patients showed infiltration of the deep lobe of parotid gland, external auditory canal, infiltration of mastoid process, skull base and the subtemporal fossa. MethodsOf the 31 patients in 13 (42%) reconstruction techniques with muscle cutaneous trapezius flap were applied in 4 (31%) patients. In group of 7 (54%) patients using a muscle flap based on the sterno-cleido-gland, in 2 (15%) patients defects were covered using the free anterior lateral thigh flap. ResultsIn all patients, healing proceeded normally. In the operated patients, one patient did not receive radical surgery due to the infiltration of the skull base. Length of hospitalization ranged between 7–21 days. In no case was lost flap, also there was no local complications at the donor. ConclusionsThe choice of treatment for malignant parotid gland tumors which are usually radioresistant is surgical resection. In patients with extensive tumors with infiltration of neighbouring organs reconstruction with use of distant flaps are recommended. It provides a good oncological and aesthetic result.

Incidence Trends of Malignant Parotid Gland Tumors in Swedish and Nordic Adults 1970 to 2009

Incidence Trends of Malignant Parotid Gland Tumors in Swedish and Nordic Adults 1970 to 2009

Head and neck MRI of Kimura disease

The purpose of our study was to describe the MR appearance of Kimura disease and to interpret the differences in appearance from malignant parotid gland tumours. MR studies of seven patients with Kimura disease were reviewed. The MR studies included T(1) weighted, T(2) weighted, short tau inversion-recovery, diffusion-weighted (DW) and dynamic contrast-enhanced imaging. Typical Kimura disease featured subcutaneous lesions, continuously infiltrated parotid lesions from the subcutaneous lesions with or without intraparotid lymphadenopathies, and reactive cervical lymphadenopathies. The subcutaneous lesions showed gradual upward enhancement on dynamic contrast-enhanced MR images. Reactive lymph nodes showed early enhancement on contrast-enhanced MR images and marked high intensity and low apparent diffusion coefficient values on DW images. An indication for making the diagnosis of Kimura disease should be the subcutaneous tissue of the head and neck showing gradual upward enhancement on dynamic contrast-enhanced MRI and a lack of high intensity on DW images, associated with reactive lymph nodes.

Oncocytoma: The Vanishing Parotid Mass

Parotid gland oncocytoma is an uncommon, benign salivary neoplasm composed of mitochondria-rich oncocytes. The purpose of this study was to correlate MR imaging and histopathology of parotid gland oncocytomas and to define the features that may distinguish these neoplasms from other benign and malignant parotid gland tumors. The MR imaging features in 9 patients with a pathologic diagnosis of oncocytoma were retrospectively reviewed. The imaging features were strikingly similar for 8 of the 9 patients. All lesions appeared T1 hypointense but isointense to the native parotid gland on fat-saturated T2 and postcontrast T1 imaging. On MR imaging, parotid gland oncocytomas share specific imaging characteristics that have not been described for benign or malignant parotid gland tumors. Oncocytomas are isointense to native parotid gland on fat-saturated T2 and T1 postcontrast MR images. Preoperative identification of correct histology may help surgical planning.

Distinguishing benign from malignant parotid gland tumours: low-dose multi-phasic CT protocol with 5-minute delay

ObjectivesTo explore the percentage enhancement wash-out ratio (PEW) and relative PEW (RPEW) of low-dose multi-phasic computed tomography (CT) in distinguishing benign from malignant parotid gland tumours.MethodsThis study was approved by the ethics committee, and informed patient consent was obtained. 51 patients with parotid tumours proven by histopathology received CT, including 18 with pleomorphic adenomas, 14 with Warthin’s tumours and 19 with malignant tumours. Size and attenuation of parotid tumours were measured. Compared with 5-min attenuation, the 30-s and 90-s PEW (PEW30, PEW90) and RPEW (RPEW30, RPEW90) were calculated.ResultsThere was a significant difference in PEW30, RPEW30, PEW90 and RPEW90 in the parotid neoplasms groups (P < 0.01), and statistical significance existed simultaneously in pleomorphic adenomas vs malignant tumours and Warthin’s tumours vs malignant tumours according to SNK-q test. The optimal diagnosis results of malignancy with 100% specificity (32/32) was obtained by using a combination of the following criteria: −70% > PEW30 < 36%, −30% > PEW30 < 19%, PEW90 > 12%, and the sensitivity (74%) for diagnosis of malignancy was yield.ConclusionsWash-out ratio may assist in differentiating the benign from malignant parotid gland tumours. Combining the percentage of enhanced wash-out ratios of CT protocols can yield diagnostic results for malignancy.

Carcinome mucoépidermoïde de la glande parotide chez le petit enfant

Mucoepidermoid carcinoma of the parotid gland is a rare malignant tumor mostly affecting adults. It accounts for 1 to 3 % of head and neck malignant tumors. It is very rarely observed in children under 10 years of age. A four-and-half-year-old boy was brought to consultation in our department, in June 2006, for a left cervical swelling having progressively increased over the previous two years. Cervical US confirmed the presence of a 2.3cm long tumor of the left parotid area, hyperechogenic and heterogenic, associated to a homolateral lymphadenopathy in the jugular and carotid region (zone II), 2cm in diameter. A total parotidectomy preserving the facial nerve was performed. The biopsy extemporaneous histological examination suggested a low-grade mucoepidermoid carcinoma. Surgery was completed by functional neck dissection. Our four-and-half-year-old patient was one of the youngest cases ever reported. Malignant parotid gland tumors are very rarely observed in children: less than 19 cases have been published worldwide. Its occurrence in a young child under ten years of age is very rare. Mucoepidermoid carcinoma accounts for one third of all malignant parotid gland tumors.