Pre-operative assessment of metastatic parotid tumors

Lymph Node Metastases from Non-Melanoma Skin Cancer of the Head and Neck

Non-melanoma skin cancer (NMSC) represents the most common malignancy in the world, comprising exceedingly common lesions such as basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC) and rare lesions such as Merkel cell carcinoma. Risk factors are widely recognized and include ultraviolet (UV) light exposure, radiation exposure, immunosuppression, and many others. As a whole, survival and functional outcomes are favorable, but each histopathological subtype of NMSC behaves differently. Treatment regimens for the primary site usually include wide surgical excision and neck dissection in cases of clinically involved metastatic lymph nodes. The elective management of draining nodal basins, however, is a contested topic. Nearly all subtypes, excluding BCC, have a significant risk of lymphatic metastases, and have been studied with regard to sentinel lymph node biopsy (SLNB) and elective neck dissection. To date, no studies have definitively established a true single standard of care, as exists for melanoma, for any of the NMSCs. As a result, the authors have sought to summarize the current literature and identify indications and management options for the management of the cervical lymphatics for each major subtype of NMSC. Further research remains critically necessary in order to develop complete treatment algorithms.

Intra-parotid lymph node metastasis in patients with non-cutaneous head and neck cancers: clinical and imaging features for differentiation from simultaneous parotid primary tumor

BACKGROUND

Although uncommon, intra-parotid lymph node (IPLN) metastasis should be considered in the differential diagnosis of parotid masses in patients with head and neck cancers.

PURPOSE

To compare the clinical and imaging features of IPLN metastases from head and neck cancers and simultaneous parotid primary tumors.

MATERIAL AND METHODS

A retrospective review of 2199 patients with non-parotid head and neck cancers revealed 63 patients who also underwent parotidectomy during curative resection of head and neck cancer. After exclusion of direct extension to the parotid gland from adjacent primary tumors (n = 12) and IPLN metastases from skin cancer (n = 5), the final study group was composed of 46 patients, including 26 (1.2%) with 33 IPLN metastases and 20 (0.9%) with 24 simultaneous parotid primary tumors. We compared clinical features of patients (sex, age, site of primary tumor, histologic type, history of prior treatment for malignancy, TNM stages, side of parotid lesion, multiplicity, and metastasis in ipsilateral cervical LNs) and the CT (location in parotid gland, maximum dimension, margins, and central necrosis or cystic change) and 18F-FDG PET/CT (maximum standardized uptake value) findings.

RESULTS

Ipsilateral level II LN metastasis was more frequent in the IPLN metastasis group than in the simultaneous parotid primary tumor group (73.1% vs. 35.0%, P < 0.05). Imaging features such as location in parotid gland, maximum dimension, margins, central necrosis or cystic change, and maximum standardized uptake value showed no significant differences between the two groups.

CONCLUSION

CT and PET/CT findings of IPLN metastasis are indistinguishable from simultaneous parotid primary tumor in patients with head and neck cancers.

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.

Metastases to the parotid nodes: CT and MR imaging findings

OBJECTIVES

To present and characterize CT and MR imaging findings of metastases to the parotid nodes.

METHODS

CT (n = 10) and MR (n = 11) images from 14 patients with metastases to the parotid nodes were reviewed. The primary tumour sites were the ocular adnexa in five patients, facial skin in four patients, upper aerodigestive tract in four patients and thyroid gland in one patient. CT and MR images were evaluated with emphasis on the size and number of parotid tumours, their location in the parotid gland, the presence of associated clinically pathological cervical nodes or previous history of cervical node metastasis, margin characteristics and the presence of central necrosis.

RESULTS

A total of 18 tumours were identified in 14 patients, with an average maximal cross-sectional diameter of 19 mm (7-44 mm). 12 patients had a single parotid tumour and 2 patients had unilateral multiple tumours; 12 tumours in 10 patients were located in the parotid tail, 6 tumours in 4 patients were located in the superficial lobe and no tumour was noted in the deep lobe. In the superficial lobe, four of six tumours were located in the pretragal area. Three of nine patients whose primary sites were the ocular adnexa or skin had associated clinically pathological cervical nodes. None of these patients had a previous history of cervical node metastasis. All five patients with other primary sites had associated pathological cervical nodes or a history of such. 11 tumours had well-defined margins and 7 tumours had ill-defined margins. Post-contrast images showed central necrosis in 2 of 11 tumours.

CONCLUSIONS

Metastases to the parotid nodes tend to present as solitary parotid masses with two preferential sites.

Sensitivity, Specificity, and Posttest Probability of Parotid Fine-Needle Aspiration: A Systematic Review and Meta-analysis

OBJECTIVES

(1) To analyze the sensitivity and specificity of fine-needle aspiration (FNA) in distinguishing benign from malignant parotid disease. (2) To determine the anticipated posttest probability of malignancy and probability of nondiagnostic and indeterminate cytology with parotid FNA.

DATA SOURCES

Independently corroborated computerized searches of PubMed, Embase, and Cochrane Central Register were performed. These were supplemented with manual searches and input from content experts.

REVIEW METHODS

Inclusion/exclusion criteria specified diagnosis of parotid mass, intervention with both FNA and surgical excision, and enumeration of both cytologic and surgical histopathologic results. The primary outcomes were sensitivity, specificity, and posttest probability of malignancy. Heterogeneity was evaluated with the I(2) statistic. Meta-analysis was performed via a 2-level mixed logistic regression model. Bayesian nomograms were plotted via pooled likelihood ratios.

RESULTS

The systematic review yielded 70 criterion-meeting studies, 63 of which contained data that allowed for computation of numerical outcomes (n = 5647 patients; level 2a) and consideration of meta-analysis. Subgroup analyses were performed in studies that were prospective, involved consecutive patients, described the FNA technique utilized, and used ultrasound guidance. The I(2) point estimate was >70% for all analyses, except within prospectively obtained and ultrasound-guided results. Among the prospective subgroup, the pooled analysis demonstrated a sensitivity of 0.882 (95% confidence interval [95% CI], 0.509-0.982) and a specificity of 0.995 (95% CI, 0.960-0.999). The probabilities of nondiagnostic and indeterminate cytology were 0.053 (95% CI, 0.030-0.075) and 0.147 (95% CI, 0.106-0.188), respectively.

CONCLUSION

FNA has moderate sensitivity and high specificity in differentiating malignant from benign parotid lesions. Considerable heterogeneity is present among studies.

Parotid metastasis from carcinoma urinary bladder treated with CyberKnife-based stereotactic body radiotherapy: case report and review of literature

Metastases to the parotid region are relatively infrequent and originate primarily from head and neck cancer. Metastases of an infraclavicular origin are uncommon. Moreover, metastasis from the carcinoma of urinary bladder (CUB) to any part of the head and neck, including parotid gland, is rare. Surgery and chemotherapy are usually offered. We report a case of solitary parotid metastasis from CUB, who was successfully treated with stereotactic body radiotherapy (SBRT) using CyberKnife. SBRT is a safe alternative in cases unwilling/unfit for surgery.

Value of fine-needle aspiration cytology in the evaluation of parotid tumors

Fine needle aspiration cytology (FNAC) is commonly used in the study of parotid masses; however controversy exists regarding its diagnostic accuracy. The objective of this study was to evaluate the effectiveness of FNAC as a preoperative diagnostic tool of parotid tumors. Sixty-five patients had satisfactory preoperative FNAC and underwent subsequent surgery to the parotid between March 2002 and July 2009 at our institution. The results of the FNAC were compared to the permanent histopathological diagnosis. The sensitivity, specificity, positive predictive value, negative predictive value, and the overall accuracy of FNAC for parotid masses were 57.9, 97.8, 91.7, 84.9, and 86%, respectively. FNAC is useful in the preoperative assessment of parotid tumors and surgical planning. The non-diagnostic and false-negative results are the limitations of FNAC that should be reduced to improve its usefulness in the evaluation of parotid tumors.

Head and neck manifestations of distant carcinomas

Metastatic tumors to the head and neck from distant carcinomas are rare lesions that epitomize the "zebras." They represent a diagnostic and therapeutic challenge for clinicians and health providers. These lesions usually rank low in the differential diagnosis list, but a history of cancer should prompt clinicians about the possibility of a metastatic lesion from a distant carcinoma. The presence of these lesions usually represents a poor prognosis. The surgeon's role in treating these lesions is to improve or maintain the patient's quality of life, taking into consideration the overall prognosis.

[Metastasis to the parotid gland]

INTRODUCTION

Metastatic disease in the parotid gland has been observed and reported in the literature, and its treatment is controversial.

MATERIAL AND METHODS

We review 48 patients with parotid tumors that underwent surgery during 1997-2004. The clinical and histogical features are reviewed.

RESULTS

Among these 48, there were 12 cases of metastatic tumors to the parotid (25%). The pathohistological analysis of these tumors revealed that 8 were epidermoid carcinoma (66%), 1 patient was a melanoma (8%), 2 lymphomas below clavicules (16%) and 1 patient with a metastasis of a primary renal cancer. All patients underwent parotidectomy and 10 also cervical neck dissection (6 cases showed cervical metastases). 8 patients received radiotherapy after surgery.

CONCLUSIONS

In our study parotid metastases are relatively common in patients submitted for parotid surgery. Often the site of origin of the primary tumor is the facial skin, and the primary tumors most commonly are melanomas or squamous-cell carcinomas, but it is possible distant primary tumors below clavicules.

Preoperative cytology in the management of parotid neoplasms

BACKGROUND

This study evaluates the diagnostic role of preoperative cytology of parotid neoplasms. The method is particularly useful in the evaluation of the parotid diseases in which the same clinical features may be treated variously. Fine-needle aspiration biopsy is a simple and well-tolerated diagnostic tool, which provides accurate information for diagnosis and follow-up of the disease. The accuracy of the method partly depends on the operator skill.

MATERIALS AND METHODS

From a series of 452 subjects who underwent parotidectomy, preoperative cytological evaluation was available in 310 and compared with histological diagnosis in a retrospective review.

RESULTS

The agreement between histotype determination using fine-needle aspiration biopsy and final histological diagnosis was 79%, specificity was 100%, sensitivity was 83%, and diagnostic accuracy was 97%.

CONCLUSION

These findings demonstrated that, given the low complication rate, preoperative cytology is particularly useful in diagnosing parotid disease and in planning the surgical strategy and approach.

MR imaging of salivary glands

Diagnostic imaging of salivary glands has been revolutionized with the advent of cross-sectional imaging modalities like CT and MR imaging. In the era before CT, imaging of the salivary glands was relatively unrewarding and was used uncommonly by ear-nose-throat surgeons. Early diagnostic tests like plain films and sialography evaluated dilated parotid ducts and calculus disease within ducts or glands. Full evaluation of salivary glands, especially deep lobes of parotid gland and masses of minor salivary glands, was not possible by these methods, however. Imaging of the parotid glands has developed significantly since that time. CT and MR imaging greatly compliment physical and endoscopic examinations (and previous favorites like sialography) by direct visualization of previously blind areas of the salivary glands and extension of the disease process in surrounding tissue planes.

MR imaging of salivary glands

In conclusion, if a parotid gland mass is bilateral, it is more likely to be Warthin's tumor, especially if it does not enhance. Less likely, it could be lymphoepithelial cyst or necrotic lymph node. A unilateral, non-enhancing mass with a high T2 signal is more likely to be a Warthin's tumor and less likely a necrotic lymph node or first branchial cleft cyst. If the mass is unilateral, shows postcontrast enhancement, has a high T2 signal, and does not invade surrounding tissue planes, it is more likely to be a pleomorphic adenoma. An intermediate to low T2 signal mass-with or without invasion of surrounding tissue planes--is more likely to be a malignant mass such as adenocystic or mucoepidermoid carcinoma. Biopsy is superior and the gold standard for diagnosis and cannot be replaced by MR imaging, however.