Diagnostic accuracy of fine-needle aspiration cytology and frozen section in primary parotid carcinoma

Update on the Treatment of Salivary Gland Carcinomas

Salivary gland carcinoma is a rare form of head and neck carcinoma, but it comprises a variety of subsites and histologic subtypes that each present with unique clinical courses and management challenges. Preoperative work-up generally consists of fine-needle aspiration cytology and MRI. However, because of the large variety of subtypes, there are often challenges obtaining a histologic diagnosis before surgery. Upfront surgery at the primary site leads to the greatest improvement in survival. Posttreatment surveillance of these patients is important. This article discusses some of the current controversies in the management of salivary gland carcinomas.

Cytopathological analysis of salivary gland cancer: REFCOR recommendations by the formal consensus method

OBJECTIVE

To determine the indications for fine-needle cytology and the modalities of frozen section pathological analysis in the management of salivary gland cancer.

MATERIAL AND METHODS

The French Network of Rare Head and Neck Tumors (REFCOR) formed a steering group who drafted a 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

Fine-needle cytology is recommended as part of the diagnostic work-up for a major salivary gland tumor suspicious for malignancy. Fine-needle cytology should be performed after MRI to avoid artifacts. Frozen section analysis is recommended to confirm the malignant nature of the tumor, to adapt the extent of resection and to indicate neck dissection. Whenever possible, the entire tumor and adjacent salivary or periglandular tissue should be sent for frozen section analysis.

CONCLUSION

Fine-needle cytology and frozen section analysis play an essential role in the management of salivary gland cancers.

Ability for fine needle aspiration and frozen section to predict extent of parotidectomy

INTRODUCTION

Several diagnostic modalities with various sensitivity and specificities can be used to evaluate a parotid mass. The aims of this project were to compare the diagnostic actionability, accuracy, and ability to accurately predict extent of surgery for FNA and frozen section during the evaluation of a parotid mass.

METHODS

A retrospective chart review of patients who underwent parotidectomy for a parotid mass from January 1, 2015 to January 30, 2022 was conducted. Actionability was defined as a pathology diagnosis or the histologic grade of a lesion, as this provided clear and useful information for the surgeon to act upon. Diagnostic accuracy was determined by comparing FNA and frozen section results to final pathology. Accuracy of extent of surgery was determined by comparing predicted extent of surgery from the FNA or frozen section result to the extent of surgery predicted by the final pathology.

RESULTS

A total of 626 patients were included in this study. FNA was obtained in 396 (63%) patients, while all neoplasms were evaluated by frozen section analysis. FNA diagnosis was actionable in 318 (80%), while frozen section diagnosis was actionable in 616 (98%) patients. Exactly 294 (92.5%) FNA diagnoses were accurate compared with 600 (98%) frozen section diagnoses. The FNA diagnosis predicted appropriate extent of surgery in 294 (74%) while the frozen section diagnosis predicted appropriate extent of surgery in 600 (96%). Among the 396 patients with FNA, frozen section was significantly more likely to accurately predict appropriate extent of surgery compared with FNA (p < 0.001).

CONCLUSION

Frozen section is more likely to yield actionable and accurate results compared with FNA. Additionally, frozen section is better than FNA in predicting the appropriate extent of surgery.

Clinicopathological characteristics of four major histological types of high-grade parotid carcinoma

OBJECTIVE

High-grade parotid carcinoma generally has a poor prognosis, and the histological type is mucoepidermoid carcinoma (MEC), salivary duct carcinoma (SDC), carcinoma ex pleomorphic adenoma (CEPA), or adenoid cystic carcinoma (AdCC) in the majority of cases.

METHODS

During the 23-year period from September 1999 to December 2022, 250 patients with parotid carcinoma underwent initial treatment and had the histopathological type of their carcinoma. Retrospective study evaluated 111 MEC, SDC, CEPA, or AdCC cases among 134 patients with high-grade parotid carcinoma. We examined pathological and clinical features and prognosis, evaluated factors associated with recurrence, and performed immunohistological examinations.

RESULTS

Pathological and clinical features and factors associated with recurrence were different for each histological type. The 10-year disease-free survival rates were as follows: MEC, 34.9%; SDC, 22.6%; CEPA, 47.1%; and AdCC, 56.3%. Human epidermal growth factor receptor type-2 and androgen receptor were positive in 48% and 56% of patients with SDC, respectively, 38% and 25% of those with CEPA.

CONCLUSION

Each histological type has its own pathological and clinical features, recurrence types, and tumor activities, suggesting that differentiating between high-grade parotid carcinomas according to histological type will improve diagnosis, and thus prognosis.

Tumores parotídeos: correlación entre estudios de imagen, punción aspiración con aguja fina y los hallazgos histopatológicos

Introducción y objetivo: Nuestro objetivo es establecer la rentabilidad del diagnóstico citológico mediante punción aspiración con aguja fina (PAAF) y la utilidad del estudio de imagen preoperatoria en el manejo de masas parotídeas. Método: Se realizó un estudio retrospectivo de una muestra de 142 pacientes con tumoración parotídea intervenidos por el Servicio de Otorrinolaringología del HUPR en los últimos 10 años, con diagnóstico preoperatorio radiológico (ecografía, TC, RNM) y citológico, mediante PAAF. Los resultados de ambas pruebas se han clasificado como positivos o negativos para malignidad y se compararon con el diagnóstico anatomopatológico. Resultados: La edad media fue de 56 años, el 61,3% eran hombres. La PAAF presentó una sensibilidad para detectar malignidad del 75% y una especificidad del 100%; con valores predictivos positivo y negativo (VPN) de 100 y 97%, respectivamente. La sensibilidad del estudio radiológico fue de 25%, y la especificidad del 99%. El valor predictivo positivo para malignidad fue de 80%, y el valor predictivo negativo, de 89%. Conclusiones: La PAAF es una prueba sencilla, pero de utilidad limitada para la orientación diagnóstica debido a su baja sensibilidad y elevados falsos negativos; sin embargo, su alta especificidad y elevado VPN hacen de la misma una prueba con mayor precisión frente a un resultado benigno o negativo. El estudio radiológico previo es útil en el diagnóstico de extensión y características tumorales, aunque se ve limitado por sí solo en el diagnóstico diferencial de malignidad. La RM se ha convertido en la modalidad de imagen de elección.  

Pilot study on the value of Raman spectroscopy in the entity assignment of salivary gland tumors

Background

The entity assignment of salivary gland tumors (SGT) based on histomorphology can be challenging. Raman spectroscopy has been applied to analyze differences in the molecular composition of tissues. The aim of this study was to evaluate the suitability of RS for entity assignment in SGT.

Methods

Raman data were collected in deparaffinized sections of pleomorphic adenomas (PA) and adenoid cystic carcinomas (ACC). Multivariate data and chemometric analysis were completed using the Unscrambler software.

Results

The Raman spectra detected in ACC samples were mostly assigned to nucleic acids, lipids, and amides. In a principal component-based linear discriminant analysis (LDA) 18 of 20 tumor samples were classified correctly.

Conclusion

In this proof of concept study, we show that a reliable SGT diagnosis based on LDA algorithm appears possible, despite variations in the entity-specific mean spectra. However, a standardized workflow for tissue sample preparation, measurement setup, and chemometric algorithms is essential to get reliable results.

Adenoid cystic carcinoma. An indolent but aggressive tumour. Part A: from aetiopathogenesis to diagnosis

Adenoid cystic carcinoma (ACC) is a relatively rare tumour of the minor and major salivary glands. It is uncommon in the parotid gland while it is much more frequent in the submandibular gland and in minor salivary and mucinous glands (oral cavity, oropharynx, and paranasal sinuses). ACC may also arise in secretory glands located in other tissues, such as in the tracheobronchial tree, oesophagus, breast, lungs, prostate, uterine cervix, lachrymal and Bartholin’s glands, and skin. The natural history of ACC is characterised by an indolent growth rate, a relatively low probability of regional lymph node metastases and a high likelihood of haematogenous dissemination. ACC has been traditionally subdivided into three histological groups (cribriform, tubular, and solid) based on solid components of the tumour. Some studies have shown that tumours with a solid growth component have a rapid fatal course, compared to tumours without a solid growth component, but other studies have failed to correlate growth patterns with clinical course. The purpose of this review is to analyse the very large number of studies (sometimes contradictory) on ACC. In this first part, the aetiology, epidemiology, histopathology, clinical behaviour and diagnostic workup are examined.

Pretherapeutic Predictive Factors for Histological High-Grade Parotid Gland Carcinoma

OBJECTIVE

The histological grade of parotid gland carcinoma (PGC) is an important prognostic factor; however, the diagnosis prior to treatment has been challenging to make. This study aimed to investigate whether the pretreatment clinical findings, including hematological inflammatory, nutritional, and immune markers, could predict the histological grade of PGC.

STUDY DESIGN

Retrospective study.

METHODS

We retrospectively enrolled 111 patients with PGC and evaluated the correlation between histological grade and pretreatment clinical findings such as age, sex, tumor staging, facial nerve paralysis, pain or tenderness, adhesion to the surrounding tissues or tumor immobility, and hematological markers.

RESULTS

Sixty patients (54%) were diagnosed with histological high-grade PGC. Univariate analysis revealed that age, T classification, N classification, TNM stage, facial nerve paralysis, adhesion/immobility, C-reactive protein (CRP), and CRP-to-albumin ratio (CAR) were significant predictors of PGC histological grade. On multivariate analysis, high T classification (T3, 4), high N classification (≥1), and elevated CRP (≥0.22 mg/dL) were independent predictors of high-grade PGC.

CONCLUSIONS

Pretreatment T classification, N classification, and CRP are significant predictors of the histological grading of PGC. Our results are useful for treatment planning and obtaining appropriate informed consent from the patients before treatment.

LEVEL OF EVIDENCE

4 Laryngoscope, 2021.

The Milan System, from Its Introduction to Its Current Adoption in the Diagnosis of Salivary Gland Cytology

Salivary gland masses are often encountered in the everyday practice of cytopathology. It is commonly known that the cytologic interpretation of these lesions can pose diagnostic problems due to overlapping cytomorphologic features. Fine needle aspiration (FNA) of salivary lesions shows good to excellent sensitivity and specificity in differentiating a neoplastic from a non-neoplastic process and in diagnosing common tumors such as pleomorphic adenoma. However, its value is limited in diagnosing specific neoplastic entities especially those with well-differentiated morphology. In light of this gap, an international group of pathologists has proposed a management-oriented, tiered classification for reporting salivary gland FNA specimens, “The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC)”. Similar to other classification systems, the MSRSGC scheme comprises six diagnostic categories, which were linked with a specific risk of malignancy (ROM) and management. In this review article, the author evaluated the published literature on FNA in diagnosing salivary gland lesions with the adoption of the Milan system since its introduction in the daily practice of salivary cytopathology.

Management of Salivary Gland Malignancy: ASCO Guideline

PURPOSE

To provide evidence-based recommendations for practicing physicians and other healthcare providers on the management of salivary gland malignancy.

METHODS

ASCO convened an Expert Panel of medical oncology, surgical oncology, radiation oncology, neuroradiology, pathology, and patient advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 2000 through 2020. Outcomes of interest included survival, diagnostic accuracy, disease recurrence, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 293 relevant studies to inform the evidence base for this guideline. Six main clinical questions were addressed, which included subquestions on preoperative evaluations, surgical diagnostic and therapeutic procedures, appropriate radiotherapy techniques, the role of systemic therapy, and follow-up evaluations.

RECOMMENDATIONS

When possible, evidence-based recommendations were developed to address the diagnosis and appropriate preoperative evaluations for patients with a salivary gland malignancy, therapeutic procedures, and appropriate treatment options in various salivary gland histologies.Additional information is available at www.asco.org/head-neck-cancer-guidelines.

Cytologic grading of primary malignant salivary gland tumors: A blinded review by an international panel

BACKGROUND

Fine needle aspiration (FNA) is commonly used for the preoperative evaluation of salivary gland tumors. Tumor grade is a key factor influencing clinical management of salivary gland carcinomas (SGCs). To assess the ability to grade nonbasaloid SGCs in FNA specimens, an international panel of cytopathologists convened to review and score SGC cases.

METHODS

The study cohort included 61 cases of primary SGC from the pathology archives of 3 tertiary medical centers. Cases from 2005 to 2016 were selected, scanned, and digitized. Nineteen cytopathologists blinded to the histologic diagnosis reviewed the digitized cytology slides and graded them as low, high, or indeterminate. The panelists' results were then compared to the tumor grades based on histopathologic examination of the corresponding resection specimens.

RESULTS

All but 2 of the 19 (89.5%) expert panelists review more than 20 salivary gland FNAs per year; 16 (84.2%) of the panelists work at academic medical centers, and 13 (68.4%) have more than 10 years' experience. Participants had an overall accuracy of 89.4% in the grading of SGC cases, with 90.2% and 88.3% for low- and high-grade SGC, respectively. Acinic cell carcinoma and mucoepidermoid carcinoma had the highest degree of accuracy, while epithelial-myoepithelial carcinoma and salivary duct carcinoma had the lowest degree of accuracy. As expected, the intermediate-grade SGC cases showed the greatest variability (high-grade, 42.1%; low-grade, 37.5%, indeterminate, 20.4%).

CONCLUSION

This study confirms the high accuracy of cytomorphologic grading of primary SGC by FNA as low- or high-grade. However, caution should be exercised when a grade cannot be confidently assigned.

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.

Usefulness of ultrasound and fine needle aspiration cytology of major salivary gland lesions

PURPOSE

To assess the clinical value of ultrasound (US) and fine needle aspiration (FNA) of salivary gland lesions prior to surgery, for preoperative decision-making and long-term follow-up/outcome.

MATERIALS & METHODS

We retrospectively analyzed the medical charts of 98 consecutive patients with major salivary gland lesions who were treated in a single medical from 2008 to 2017. Preoperative US and FNA was performed in all patients. Cytology results were compared with histopathological diagnoses. The correlation between preoperative US findings, cytology and histopathological diagnoses was assessed.

RESULTS

Twenty-three specimens were histopathologically malignant, and 75 were diagnosed as benign. Three false-positive results diagnosed as malignant in cytology had a final histology of sialadenitis, pleomorphic adenoma and Warthin's tumor, respectively. In six cases, cytology yielded false-negative results. The overall accuracy of FNA in distinguishing benign from malignant lesions was 91%. Sensitivity was 70% and specificity 93%. There was no significant correlation between US features and final pathology, but larger size had some correlation with malignancy (p = 0.306). No complications were observed during or after performing FNA.

CONCLUSION

FNA from salivary gland lesions is safe and in many cases can help in preoperative decision making or surgical planning. Hence, the results of FNA cytology should have an integral role in clinical decision-making and management of major salivary gland lesions. False-negative results do occur and therefore should be used only as an adjunctive measure.

Preoperative biopsy in parotid malignancies: Variation in use and impact on surgical margins

OBJECTIVES

Determine rate of preoperative biopsy in parotid malignancies, identify factors associated with its use, and its association with surgical margins.

STUDY DESIGN

Retrospective cohort.

SETTING

Commission on Cancer-Accredited Institutions.

SUBJECTS AND METHODS

We included 5533 patients treated surgically for a parotid malignancy 2004-2014 in the National Cancer Database. Chi-squared tests, univariable, and multivariable logistic regressions were used to evaluate predictors of preoperative biopsy (defined as needle, aspiration, or incisional), and associate biopsy with surgical margins.

RESULTS

Preoperative biopsy was utilized in 26.0% of patients. Biopsy was more likely in patients >60 years (odds ratio [OR]: 1.19, P = .035), advanced clinical T stage (vs. T1,T2 OR: 1.23, P = .009; T3 OR: 1.26, P = .026; T4A OR: 2.05, P < .001), advanced clinical N stage (vs. N0, N1: OR: 1.39, P = .013; N2/3: OR: 1.63, P < .001), in academic centers (OR: 1.18, P < .024), and in higher volume centers (vs. low, medium OR: 1.28, P = .002; high OR: 2.16, P < .001). Biopsy use increased over time (vs. 2004-2006, 2007-2010 OR: 1.20, P = .047; 2011-2014 OR: 1.39, P < .001). Biopsy was associated with a reduced risk of positive margins in patients with clinical T1 stage (OR: 0.70, P = .012), and younger than 61 (OR: 0.79, P = .036).

CONCLUSION

The national rate of preoperative biopsy in parotid malignancy is low at 26.0%, but has increased over time. Preoperative biopsy is associated with a reduced risk of positive margins in younger patients and those with early clinical stage, suggesting its increased use may improve surgical outcomes and decrease reoperation or adjuvant therapy in these subgroups of patients.

LEVEL OF EVIDENCE

3 Laryngoscope, 130:1450-1458, 2020.

Apparent diffusion coefficient (ADC) histogram analysis: differentiation of benign from malignant parotid gland tumors using readout-segmented diffusion-weighted imaging

OBJECTIVES

To explore the utility of whole-lesion apparent diffusion coefficient (ADC) histogram analysis for differentiating parotid gland tumors following readout-segmented diffusion-weighted imaging (RESOLVE).

METHODS

80 patients (40 with pleomorphic adenomas, 14 with Warthin tumors, and 26 with malignant parotid gland tumors) who underwent routine head-and-neck MRI and RESOLVE examinations, were retrospectively evaluated. RESOLVE data were acquired from a MAGNETOM Skyra 3T MR system. Eleven whole-lesion histogram parameters derived from histogram analysis (ADC_mean, ADC_minimum, ADC_maximum, ADC_1th, ADC_10th, ADC_50th, ADC_90th, ADC_99th, skewness, variance and kurtosis) were calculated for each patient using MaZda. Receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic performance of the ADC for distinguishing among the three groups.

RESULTS

In total, nine parameters (ADC_minimum, ADC_maximum, ADC_mean, ADC_10th, ADC_50th, ADC_90th, ADC_99th, variance, skewness) were statistically significant (all p < 0.05) for all three groups, in the comparison of pleomorphic adenomas to Warthin tumors; the ADC_mean, ADC_50th, and skewness revealed high diagnostic efficiency with areas under the receiver operating characteristic curve of 0.976, 0.970, and 0.970, respectively. In the comparison of pleomorphic adenomas to malignant parotid gland tumors, these nine parameters were also found to be statistically different (all p < 0.05); the ADC_mean, ADC_10th and ADC_50th revealed high diagnostic efficiency with area under the curve of 0.851, 0.866, and 0.841, respectively. However, in the comparison of Warthin tumors to malignant parotid gland tumors, only three parameters (ADC_mean, ADC_50th, skewness) were statistically significant (all p < 0.05).

CONCLUSIONS

Whole-lesion ADC histograms are effective in differentiating common parotid gland tumors.

Amide Proton Transfer-weighted MRI in the Diagnosis of Major Salivary Gland Tumors

Amide proton transfer-weighted magnetic resonance imaging (APTw-MRI), which is effective in tumor characterization, has expanded its role in the head and neck. We aimed to evaluate the diagnostic ability of APTw-MRI in differentiating malignant from benign major salivary gland tumors compared with diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE)-MRI. Between December 2017 and November 2018, 38 subjects, who were diagnosed with major salivary gland tumors and who underwent preoperative 3 T MRI, including APTw-MRI, DWI, and DCE-MRI, were included in this retrospective study. Twenty-three subjects had benign tumors, and fifteen had malignancies. APTw-signals of the tumors were measured and compared according to the histopathological diagnosis. Using receiver operating characteristic curve analysis, diagnostic performance of APTw-MRI was evaluated and compared with DWI and DCE-MRI using DeLong test. The maximum, mean, and median APTw-signals were significantly higher in malignant than in benign tumors (P < 0.001). The mean and maximum APTw-signals showed excellent area under the curve for predicting malignant tumors (0.948 and 0.939), which were significantly higher than the combining use of DWI and DCE-MRI (0.780) (P = 0.021 and 0.028). Therefore, APTw-MRI could be a useful tool for differentiating malignant from benign major salivary gland tumors, and can be applicable in the clinical setting.

A Call for Universal Acceptance of the Milan System for Reporting Salivary Gland Cytopathology

OBJECTIVES

The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) established a standardized, tiered reporting system for salivary gland fine-needle aspiration (FNA) that has gained international acceptance among cytologists. Our goal was to review the key features of the MSRSGC to familiarize the surgical community with this system and its application to the FNA evaluation of salivary gland masses.

METHODS

A comprehensive review of the MSRSGC and its application in clinical practice.

RESULTS

The MSRSGC consists of six major diagnostic categories: 1) nondiagnostic, 2) non-neoplastic, 3) atypia of undetermined significance, 4) neoplasm (benign or salivary gland neoplasm of uncertain malignant potential), 5) suspicious for malignancy, and 6) malignant. Each diagnostic category is associated with an implied risk of malignancy with implications for clinical management.

CONCLUSIONS

The MSRSGC is similar to the system used for reporting thyroid FNA, which is familiar to most otolaryngologists and head and neck surgeons. As this reporting system continues to gain popularity among pathologists, widespread understanding by surgeons will be important to standardize communication and classification of salivary gland cytopathology to improve clinical care. Laryngoscope, 130:80-85, 2020.

Coincidence of Malignant Melanoma and an Incidently Discovered Parotid Mass Presenting a Diagnostic Challenge

Parotid masses coincided with skin tumors in head and neck region may represent a serious diagnostic challenge. Conventional imaging modalities such as computed tomography, magnetic resonance imaging may help to determine nature of the masses. Positron emission tomography - computed tomography imaging is reported to be useful for the detection of malignancy in the parotid gland. But in some situations all of them become insufficient. We present a case of cheek malignant melanoma with an incidentally discovered parotid mass during the investigation. We describe the problems experienced in the course of differential diagnosis and decision making in terms of surgical management. As a result, the most reliable diagnosis of suspicious parotid lesions accompanying head and neck melanomas comes from frozen section analyses. The other diagnostic tools are not reliable enough to allow a safe surgical plan in terms of regional treatment; however, the significance of positron emission tomography - computed tomography in distant metastasis investigation should always be kept in mind.

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.

Bilateral Synchronous Mucoepidermoid Carcinoma of the Parotid Gland

Mucoepidermoid carcinoma is the most common malignant tumor of the parotid; however, its synchronous occurrence in both of the parotid glands is extremely rare. Herein, we presented a case of 53-year-old man with bilateral synchronous mucoepidermoid carcinoma of the parotid gland treated with surgery.

The patient mainly complained of a painless mass in the left parotid gland. A mass located in the right parotid gland was incidentally detected by imaging. Based on cytopathology, left total parotidectomy was performed while preserving the facial nerve with ipsilateral neck dissection, and 5 weeks later, right superficial parotidectomy was performed. At the 3-year follow-up, there was no recurrence in the parotid regions and the neck.

A detailed examination for parotid masses is suggested for identifying possible occult synchronous tumors in the contralateral side or in other salivary glands. A close follow-up is also recommended for the risk of future occurrence of metachronous tumors.

A clinicopathological study of parotid carcinoma: 18-year review of 171 patients at a single institution

BACKGROUND

This study investigated the clinical outcomes of patients with parotid carcinoma at a single institution during an 18-year period, with the focus on diagnosis, treatment, and survival.

METHODS

The subjects were 171 patients with parotid carcinoma treated at our department during the 18-year period from September 1999 to August 2017. There were 19 patients in stage I, 65 patients in stage II, 22 patients in stage III, and 65 patients in stage IV. The symptoms, preoperative diagnosis, node metastasis, survival rate, prognostic factors, and immunohistological findings were investigated.

RESULTS

Preoperative diagnosis of the histological grade by fine-needle aspiration cytology was only possible in 34% of the patients, while the histological grade was correctly determined by frozen section biopsy in 72%. The overall frequency of lymph node metastasis was 29%, with 59% in patients with high-grade carcinoma and only 6% in those with low-/intermediate-grade tumors. The disease-specific 5-year survival rate was 100% for patients in stage I, 95.2% in stage II, 70.4% in stage III, and 45.1% in stage IV. Multivariate analysis showed that the pathological grade was the most important prognostic factor. Immunohistological investigation showed patients with HER-2 or androgen receptor-positive tumors had a significantly worse prognosis.

CONCLUSIONS

Although a high-grade tumor is the most important prognostic factor, preoperative diagnosis of the grade was not always accurate. Since advanced cancer has a poor prognosis with a limited response to surgery and radiation therapy, development of new treatment strategies, such as molecular-targeting therapies directed against HER-2 and AR, is required.

The value of combining conventional, diffusion-weighted and dynamic contrast-enhanced MR imaging for the diagnosis of parotid gland tumours

OBJECTIVES

The aim of this study was to determine the value of combining conventional MRI, diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE)-MRI in diagnosing solid neoplasms in the parotid gland.

METHODS

A total of 148 subjects (101 subjects with benign and 47 subjects with malignant tumours) were evaluated with conventional MRI, DWI and DCE-MRI prior to surgery and pathologic verification. The items observed with conventional MRI included the shape, capsule and signal intensity of parotid masses. The apparent diffusion coefficient (ADC) was calculated from DWI that was obtained with a b-factor of 0 and 1000 s mm^-2. A time-intensity curve (TIC) was obtained from DCE-MRI.

RESULTS

There were significant differences (p < 0.01) in the shape, capsule, ADC and TIC between benign and malignant parotid tumours. Irregular neoplasms without a capsule, ADC <1.12 × 10^-3 mm² s^-1 and a plateau enhancement pattern were valuable parameters for predicting malignant neoplasms. A combination of all of these parameters yielded sensitivity, specificity, accuracy, positive-predictive value and negative-predictive value of 85.1%, 94.1%, 91.2%, 87.0% and 93.1%, respectively.

CONCLUSIONS

A combined analysis using conventional MRI, DWI and DCE-MRI is helpful in distinguishing benign from malignant tumours in the parotid gland.

Elective neck dissection versus observation in primary parotid carcinoma

OBJECTIVE:

To evaluate the efficacy of elective neck dissection in the clinically negative neck of patients with primary carcinoma of the parotid gland.

STUDY DESIGN AND SETTING:

A retrospective analysis was undertaken at a university Department of Otorhinolaryngology-Head and Neck Surgery on 83 previously untreated patients with primary carcinoma of the parotid gland and a clinically negative neck. The reliability of fine needle aspiration cytology, frozen section, and the clinico-pathologic findings of patients with occult neck metastases were analyzed. The regional recurrence rate and the outcome were compared among 2 groups; one with elective neck dissection (N = 41) and one without elective neck dissection (N = 42).

RESULTS:

The diagnosis of malignancy was known preoperatively in 59 (71%) cases, the exact histologic tumor type in 36 (43%) and the grade in 37 (44%) of 83 cases. Occult metastases were detected in 8 (20%) of 41 cNO patients, in 5 cases associated with a high-grade and in 3 cases with a low-grade carcinoma. Recurrence of disease developed in 5 (12%) patients in the elective neck dissection group and in 11 (26%) patients in the observation group. All of the 7 neck recurrences occurred in the observation group. The 5-year actuarial and disease-free survival rate was 80% and 86% for patients with elective neck dissection and 83% and 69% for patients without neck dissection.

CONCLUSION AND SIGNIFICANCE:

A routine elective neck dissection is suggested in all patients with primary carcinoma of the parotid gland. The efficacy of elective neck dissection, nevertheless, has never been evaluated prospectively.

The role of pre-operative CT-guided FNAB for parapharyngeal space tumors

Objective

To determine the role of computed tomography (CT)-guided fine needle aspiration biopsy (FNAB) in surgical planning for parapharyngeal space (PPS) tumors.

Design and Setting

Chart review of 49 consecutive patients with surgically treated PPS tumors from 1995 to 2005.

Results

Twenty-nine patients had CT-guided FNAB. A cytopathologic diagnosis that was the same as final pathology was rendered in 14 (48%) patients; suggestive but not conclusive in 6 (21%) patients; discordant in 3 (10%) patients; and 6 (21%) patients had a nondiagnostic result. Fourteen of 15 patients who had a final histopathologic finding of pleomorphic adenoma had a correct or highly suggestive preoperative FNAB diagnosis. The positive predictive value for CT-guided FNAB to identify benign tumors is 90%, (18 of 20) but to identify malignant PPS tumors is 75% (3 of 4).

Conclusion

CT-guided FNAB of PPS tumors is helpful to predict the nature of the PPS tumors (especially benign), which allows the surgeon and patient to plan for treatment, accordingly.

Postoperative Radiation Therapy for T1 and T2 Primary Parotid Carcinoma: Is it Useful?

OBJECTIVE: The benefit of postoperative radiation for advanced primary parotid carcinoma has been reported previously, whereas studies to evaluate the usefulness of postoperative radiation for T1 and T2 parotid carcinomas have never been performed.

STUDY DESIGN AND SETTING: Retrospective analysis on 58 previously untreated patients with T1 and T2 parotid carcinomas. In 34 patients, postoperative radiation was included in the treatment protocol and in 24 patients, no postoperative radiation was applied.

RESULTS: A local recurrence was observed in 8 of 24 (33%) patients withoht and in 1 of 34 (3%) patients with postoperative radiation ( P < 0.5). The 5-year actuarial and disease-free survival rate was 83% and 70% for patients without postoperative radiation and 93% and 92% for patients with postoperative radiation.

CONCLUSION AND SIGNIFICANCE: Local recurrence was less often observed in patients with postoperative radiation. Nevertheless, prospective randomized studies are needed to confirm the usefulness of postoperative radiation in early carcinomas.

EBM rating: B-3b

The Utility of Fine Needle Aspiration in Parotid Malignancy

OBJECTIVE: To determine clinical utility of fine needle aspiration (FNA) in parotid neoplasia.

STUDY DESIGN AND SETTING: Retrospective cohort study.

METHODS: FNA and final pathology data were reviewed for patients who underwent parotidectomy for malignancy. Surgical outcomes were compared between patients with malignant cytology versus nonmalignant/nondiagnostic cytology.

RESULTS: Twenty-seven of 33 primary malignant parotid lesions underwent FNA. Seventeen (63.0%) patients were diagnosed with cancer on FNA. The remaining 16 patients did not undergo FNA (n = 6), had a nondiagnostic FNA specimen (n = 5), or were incorrectly diagnosed with a benign lesion (n = 5). Patients who went on to parotidectomy with intent to treat malignancy based on FNA had significantly higher rates of upfront neck dissections (47.1% vs 12.5%, P = 0.036) as well as clear pathological margins (70.6% vs 31.3%, P = 0.027) vs those with nonmalignant FNA diagnoses.

CONCLUSIONS: Preoperative FNA diagnosis of malignancy improves surgical treatment of parotid cancer.

SIGNIFICANCE: FNA in the evaluation of parotid masses should strongly be considered.

Salivary Duct Carcinoma of the Parotid: Outcomes with a Contemporary Multidisciplinary Treatment Approach

OBJECTIVE

Salivary duct carcinoma (SDC) is a rare and aggressive malignancy for which an optimal treatment algorithm is lacking. We endeavored to assess the current treatment outcomes for SDC with a multimodality treatment approach combining surgery with adjuvant radiotherapy ± concurrent chemotherapy.

STUDY DESIGN

Case series with chart review.

SETTING

A National Cancer Institute-designated comprehensive cancer center.

SUBJECTS AND METHODS

The clinical record of 17 patients with salivary duct carcinoma were analyzed to assess locoregional control, recurrence-free survival, and overall survival.

RESULTS

All SDC cases (n = 17) were managed with surgical resection, followed by adjuvant radiotherapy (47.1%) or concurrent chemotherapy and radiotherapy (52.9%). Median patient follow up was 37 months. An aggressive disease course was generally observed, with 3-year recurrence-free survival and overall survival of 34.4% and 35.5%, respectively. The majority of recurrences were distant. Intensification with adjuvant concurrent chemotherapy was not associated with improved outcomes on univariate survival analysis.

CONCLUSION

For salivary duct carcinoma, a multimodality treatment approach is associated with acceptable locoregional control rates but poor distant control and overall survival. Novel systemic therapies may be needed to optimize clinical outcomes.

Partial sialoadenectomy for the treatment of benign tumours in the submandibular gland

The conventional treatment for benign tumours arising in the submandibular gland (SMG) has always involved whole gland excision with the tumour. In light of developments in parotid gland functional surgery, this prospective study was performed to evaluate the effectiveness and safety of partial sialoadenectomy (PS) for benign tumours in comparison with conventional total sialoadenectomy (TS). Thirty-one consecutive patients with a preoperative diagnosis of benign tumour in the SMG were included in the study from December 2008 to December 2010. Eleven patients were treated with PS and 20 patients underwent conventional TS. Salivary gland function and surgery-related complications were assessed. No difference in resting saliva flow was found between the two groups before the operation, while this was significantly higher in the PS group than in the TS group at 1 year after surgery (P=0.009). With regard to complications, there was less deformity in facial appearance in the PS group. There was no recurrence in any of the 31 patients during the follow-up period (range 41-82 months). It is believed that this modification to SMG surgery is consistent with the idea of functional and minimal invasive salivary gland surgery. This technique represents a good choice for the management of benign tumours of the SMG for appropriately selected cases.

Preoperative Diagnostic Strategy for Parotid Gland Tumors Using Diffusion-Weighted MRI and Technetium-99m Pertechnetate Scintigraphy: A Prospective Study

Objective

Fine needle aspiration cytology (FNAC) for diagnosis of a parotid gland tumor is widely used but its sensitivity is low and non-diagnostic rate is relatively high. In contrast, core needle biopsy (CNB) has a higher sensitivity and lower rate of sampling errors but has a higher risk of injury to adjacent organs such as facial nerve than FNAC. Screening of patients with parotid gland tumors to identify cases of pleomorphic adenoma (PA) and Warthin tumor (WT) may allow CNB to be confined to patients without PA and WT. We established an algorithm for preoperative diagnosis and management of parotid gland tumor using diffusion-weighted MRI and ^99mTc pertechnetate scintigraphy. This algorithm was developed with the goal of maximal reduction of the number of patients in whom CNB is required. The purpose of the study is to validate our algorithm prospectively.

Methods

A prospective study was conducted in 71 cases who were newly diagnosed with parotid gland tumor and 53 cases were enrolled in the study. In the algorithm, PA (high apparent diffusion coefficient (ADC) _mean≥1.5×10⁻³ mm²/s) and non-PA (low ADC_mean<1.5×10⁻³ mm²/s) cases are first distinguished based on the ADC_mean on diffusion-weighed MRI. Second, among suspected non-PA cases, WT and non-WT are distinguished using technetium-99m pertechnetate scintigraphy. CNB is then performed only in probable non-PA and non-WT cases.

Results

Although CNB was only required in 40% (21/53) of all cases, we made a preoperative histopathological diagnosis with an accuracy of 87% (46/53) and we correctly diagnosed whether a tumor was benign or malignant with an accuracy of 96% (51/53). Preoperative surgical planning had to be changed during surgery in only one case (2%)

Conclusions

Our algorithm is valuable in terms of clinical practice with highly potential for preoperative diagnosis and with less risk of CNB procedure.

Differentiation of benign and malignant lesions of the tongue by using diffusion-weighted MRI at 3.0 T

OBJECTIVES

Diffusion-weighted MRI (DWI) has been introduced in head and neck lesions and adds important information to the findings obtained through conventional MRI. The purpose of this study was to assess the role of DWI in differentiating benign and malignant lesions of the tongue at 3.0-T field strength imaging.

METHODS

78 patients with 78 lingual lesions underwent conventional MRI and DWI with b-values of 0 and 1000 s mm(-2) before therapy. The apparent diffusion coefficient (ADC) maps were reconstructed, and the ADC values of the lingual lesions were calculated and compared between benign and malignant lesions of the tongue.

RESULTS

The mean ADC values of the malignant tumours, benign solid lesions and cystic lesions were (1.08±0.16)×10(-3), (1.68±0.33)×10(-3) and (2.21±0.35)×10(-3) mm2 s(-1), respectively. The mean ADC values of malignant tumours were significantly lower (p<0.001) than those of benign solid lesions, and the mean ADC values of benign solid lesions were significantly lower (p<0.001) than those of cystic lesions. Receiver operating characteristic analysis showed that when an ADC value<.31×10(-3) mm2 s(-1) was used for predicting malignancy, the highest accuracy of 95.3%, sensitivity of 92.6% and specificity of 97.3% were obtained.

CONCLUSIONS

ADC values of benign and malignant lesions are significantly different at 3.0-T imaging. DWI can be applied as a complementary tool in the differentiation of benign and malignant lesions of the tongue.

Evaluation of usefulness of fine-needle aspiration cytology in the diagnosis of tumours of the accessory parotid gland: a preliminary analysis of a case series in Japan

CONCLUSION

The accuracy and sensitivity of fine-needle aspiration cytology (FNAC) in this analysis were not satisfactory, and the false-negative rate seemed to be higher than for parotid tumours. The possibility of low-grade malignancy should be considered in the surgical treatment of accessory parotid gland (APG) tumours, even if the preoperative results of FNAC suggest that the tumour is benign.

OBJECTIVES

Little is known about the usefulness of FNAC in the preoperative evaluation of APG tumours, probably due to the paucity of APG tumour cases. We examined the usefulness of FNAC in the detection of malignant APG tumours.

METHODS

We conducted a retrospective analysis of 3 cases from our hospital, along with 18 previously reported Japanese cases. We compared the preoperative FNAC results with postoperative histopathological diagnoses of APG tumours and evaluated the accuracy, sensitivity, specificity and false-negative rates of FNAC in detecting malignant APG tumours.

RESULTS

There were four false-negative cases (19.0%), three of mucoepidermoid carcinomas and one of malignant lymphoma. One false-positive result was noted in the case of a myoepithelioma, which was cytologically diagnosed as suspected adenoid cystic carcinoma. The accuracy, sensitivity and specificity of FNAC in detecting malignant tumours were 76.2%, 60.0% and 90.9%, respectively.

[Diagnostic accuracy of fine needle aspiration cytology in parotid tumours]

INTRODUCTION AND OBJECTIVES

Fine needle aspiration cytology (FNAC) is a globally accepted technique in the preoperative evaluations of head and neck tumours; however, the effectiveness in the interpretation of salivary glands neoplastic lesions is still controversial. The objective of this study consisted of assessing the efficacy of FNAC in preoperative diagnosis of parotid tumours.

METHODS

This retrospective study was conducted using 93 patient samples with parotid gland tumoral pathology, treated at the Otorhinolaryngology Department in our institution during the 2007-2011 period. Preoperative FNAC was employed and the patients subsequently submitted to surgical excision with histopathological diagnosis of the specimen. Cytology results were classified as negative for malignancy, positive for malignancy or insufficient sample, and later compared with the definitive histological diagnosis.

RESULTS

The mean age of the studied sample was 52.9 years (range: 11 to 88 years); 55.9% were men. The FNAC showed significant sensitivity of 57.1%, with a specificity of 95.1%, for detecting malignancy in parotid gland tumours. The positive and negative predictive values for malignancy were 50 and 96.3%, respectively.

CONCLUSIONS

FNAC is considered a simple test but of limited use for diagnostic guidance in tumour pathology of the parotid gland in our environment, mainly because of its low sensitivity. However, the high specificity and high negative predictive value of FNAC makes it a more accurate test in benign or negative result cases.

Reversible facial nerve palsy due to parotid abscess

INTRODUCTION

A facial nerve palsy combined with parotid enlargement usually suggests malignancy. It is highly unusual for facial nerve palsy to result from a benign situation such as inflammation or infection of the gland.

PRESENTATION OF CASE

We present a rare case of facial nerve palsy due to parotid abscess.

DISCUSSION

A literature search retrieved thirty-two cases of facial nerve palsy due to benign parotid lesions since 1969. Only nine reported the presence of a parotid abscess. The etiology of paralysis remains unknown although certain factors such as the virulence of the offending organisms or perineuritis, have been suggested. Best diagnostic evaluation and management are discussed.

CONCLUSION

In clinical practice, exclusion of malignancy is mandatory, as it represents the most common cause of facial palsy in the presence of a parotid lump.

Diagnostic accuracy of fine needle aspiration cytology for high-grade salivary gland tumors

BACKGROUND

Preoperative differentiation between high-grade malignancy and others (benign or low-grade tumors) is more important than differentiation between malignant and benign tumors for surgical planning, treatment outcome, and prognosis in salivary gland tumors. Fine needle aspiration cytology (FNAC) has a relatively low sensitivity for differentiating malignant from benign salivary tumors. However, the diagnostic performance of FNAC has not been studied in predicting high-grade salivary malignancy, which can significantly affect patient care.

METHODS

Experienced cytopathologists reevaluated the adequate FNAC on 521 salivary gland tumors. The diagnostic performances of FNAC for total malignancy and high-grade malignancy were calculated, and the results were validated in independent 105 cases. In cases of high-grade cancer on FNAC, we recorded the additional diagnostic procedures and the change of surgical extent to decide how FNAC impacts clinical practice.

RESULTS

The sensitivity, specificity, and diagnostic accuracy of FNAC in differentiating malignant from benign tumors were 64.2 % (95 % confidence interval 52.3-75.0), 98.4 % (96.5-99.3), and 92.1 % (89.1-94.6). Meanwhile, FNAC predicted high-grade malignancy accurately (94.6 % [80.0-99.5], 99.2 % [97.8-99.7], 98.9 % [97.3-99.6], respectively), a finding reproduced with similar results in the validation set. FNAC indicative of high-grade malignancy added additional imaging assessments in 94.9 %, frozen biopsy samples during surgery (tumor and lymph nodes) in 71.2 %, and changed the extent of surgery in 59.0 %.

CONCLUSIONS

FNAC has an excellent diagnostic performance in discriminating high-grade salivary cancer, which guides clinical decision and surgical planning in salivary gland tumors.

Accuracy of fine needle aspiration cytology of salivary gland lesions: routine diagnostic experience in Bangkok, Thailand

Fine needle aspiration (FNA) cytology is well accepted as a safe, reliable, minimal invasive and cost-effective method for diagnosis of salivary gland lesions. This study evaluated the accuracy and diagnostic performance of FNA cytology in Thailand. A consecutive series of 290 samples from 246 patients during January 2001-December 2009 were evaluated from the archive of the Anatomical Pathology Department of our institution and 133 specimens were verified by histopathologic diagnoses, obtained with material from surgical excision or biopsy. Cytologic diagnoses classified as unsatisfactory, benign, suspicious for malignancy and malignant were compared with the histopathological findings. Among the 133 satisfactory specimens, the anatomic sites were 70 (52.6%) parotid glands and 63 (47.4 %) submandibular glands. FNA cytological diagnoses showed benign lesions in 119 cases (89.5 %), suspicious for malignancy in 3 cases (2.2 %) and malignant in 11 cases (8.3%). From the subsequent histopathologic diagnoses, 3/133 cases of benign cytology turned out to be malignant lesions, the false negative rate being 2.2 % and 1/133 case of malignant cytology turned out to be a benign lesion, giving a false positive rate was 0.8%. The overall accuracy, sensitivity, specificity, positive predictive value and negative predictive value were 97.0% (95% CI, 70.6%-99.4%), 81.3% (95% CI, 54.4%-96.0%), 99.1% (95% CI, 95.4%-100%), 92.9% (95% CI, 66.1%-99.8), 97.5% (95% CI, 92.8%-99.5%), respectively. This study indicated that FNA cytology of salivary gland is a reliable and highly accurate diagnostic method for diagnosis of salivary gland lesions. It not only provides preoperative diagnosis for therapeutic management but also can prevent unnecessary surgery.

Diagnosis and treatment outcomes for patients with lymphoma of the parotid gland

OBJECTIVES/HYPOTHESIS

Lymphoma of the parotid gland (LPG) is a rare disease. Clinical diagnosis is difficult, due to a lack of specific symptoms and findings. The aim of this study is to evaluate the diagnostic workup based on the analysis of our cases of LPG and to present the stage-dependent treatment outcome.

STUDY DESIGN

Retrospective case-control study.

METHODS

From 1992 to 2008, 697 patients at our institution underwent surgery because of a parotid tumor. Among 246 malignancies, an LPG was found histologically in 28 cases (4%). Staging was performed according to the Ann Arbor classification, and treatment was performed by radiotherapy and/or chemo/immunotherapy. The patients were retrospectively analyzed.

RESULTS

No specific symptoms were found, with the main finding being a unilateral, painless, slowly progressing parotid mass. The sensitivities of imaging and fine-needle aspiration cytology in detecting LPG were 41% and 12%, respectively. Histology was the key to diagnosis, and frozen sections often revealed the diagnosis during surgery, which obviated the need for more extensive surgery in 89% of cases. The 5-year disease-specific survival estimates were 100% and 75% for early tumor stages (I and II) and advanced stages (III and IV), respectively.

CONCLUSIONS

When the precise nature of a parotid mass remains obscure after fine-needle aspiration cytology and imaging, but LPG is clinically suspected, surgical tissue sampling with frozen sections appears to be a valid option and can prevent the need for more extensive surgery. The treatment outcome for LPG is favorable.

Pleomorphic adenoma of the parotid: formal parotidectomy or limited surgery?

BACKGROUND

Optimal surgery for pleomorphic adenoma of the parotid is controversial. In the present review, we discuss the advantages and disadvantages of the various approaches after addressing the surgical pathology of the parotid pleomorphic adenoma capsule and its influence on surgery.

DATA SOURCES

PubMed literature searches were performed to identify original studies.

CONCLUSIONS

Almost all pleomorphic adenomas can be effectively treated by formal parotidectomy, but the procedure is not mandatory. Extracapsular dissection is a minimal margin surgery; therefore, in the hands of a novice or occasional parotid surgeon, it may result in higher rates of recurrence. Partial superficial parotidectomy may be a good compromise. The tumor is removed with a greater cuff of healthy parotid tissue than in extracapsular dissection. This may minimize the recurrence rate. On the other hand, the removal of healthy parotid tissue compared with formal parotidectomy is limited, thus minimizing complications such as facial nerve dysfunction and Frey syndrome.

Adenocarcinoma of the parotid salivary gland in a cow

A 6-year-old Girolando dairy cow was presented for evaluation of a large subcutaneous facial mass. Fine-needle aspirates of the mass contained many neoplastic cells with high nuclear:cytoplasmic ratios arranged in sheets and loosely cohesive clusters with streaming erythrocytes and neutrophils in the background. Neoplastic cells were 13-25 μm in diameter and were round to cuboidal with variably distinct borders. Based on the signalment, anatomic location, and cytologic findings, differential diagnoses included salivary adenocarcinoma, squamous cell carcinoma, and mucoepidermoid carcinoma. The cow was euthanized and a necropsy was performed. The primary neoplasm arose from the left parotid salivary gland and meastatic tumor was found in the regional lymph nodes and lung. Histologically, the tumor was composed of anastomosing and irregular solid islets surrounded by scant stroma. Cells were negative for periodic acid-Schiff (PAS), PAS-diastase, and Alcian blue pH 2.5 stains, used to detect mucin. On immunohistochemical analysis, neoplastic luminal salivary gland cells expressed cytokeratin, but not S100, α-smooth muscle actin, or vimentin. Peripheral cells of neoplastic islets were immunoreactive for p63. The final diagnosis was nonsecretory adenocarcinoma of the parotid salivary gland.

[Intraoperative frozen section diagnosis of head and neck tumors: possibilities, limitations, pitfalls and tips for the daily practice]

Intraoperative consultation (synonym: frozen section diagnostics) has increasingly gained significance for the daily practice in head and neck surgery. The main aim of this investigation method which is usually associated with much stress and effort is to facilitate an optimal and timely oncological surgical treatment of neoplastic diseases with a minimum rate of postoperative functional disturbance. In order to achieve this purpose pathologists are expected to deliver as much correct information as possible to accurately influence intraoperative surgical decisions. At the same time this aim should be reached without significantly and unnecessarily increasing the workload for the pathology laboratory and without significantly inducing tissue artifacts. This would otherwise negatively influence the tissue quality for permanent section examination and consequently the overall quality of diagnosis and tumor staging. Thus, the quality and efficacy of frozen sections span a spectrum with the highest quality having the least possible false negative rate on the one hand and a false positive result of approximately zero on the other hand. Sticking to this approach would result in a high positive impact on the surgical treatment of a variety of neoplastic diseases and help to minimize or even eliminate the rate of medicolegal consequences.