The significance of CT scan or MRI in the evaluation of salivary gland tumors
Introduction
Imaging modalities such as CT scan or MRI are frequently employed in the evaluation of tumors occurring in the salivary glands. However, the efficacy of these imaging modalities in assessing the nature of the mass are still not well-defined. For simple mass lesions in the parotid or submandibular glands, a physical examination might be enough for the decision of operation and the final diagnosis would be made by histologic examination of the surgical specimens. The CT scan and/or MRI might be more useful to evaluate salivary gland masses with signs of suggesting malignancy, such as fixation to the adjacent tissues or facial paralysis, for better surgical planning. Imaging techniques can provide important information about the extent and location of the mass [1]. However, even in cases of clinically suspected malignancy, radiologists may not be able to comment on if the lesion is malignant or not. Furthermore, some cases of discrepancy have been seen between the radiological opinions and histologic diagnoses, which triggered several questions; to what extent can CT scan or MRI play a role in differentiating malignant tumors from benign lesions? What are characteristic findings suggesting malignancy in these modalities? Which modality should be chosen to evaluate the masses in the salivary glands for preoperative evaluation?
This study has tried to answer these questions by a direct comparison of radiological interpretations and histological diagnoses.
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Materials and methods
The CT scans or MRIs of 147 cases were retrospectively analyzed whose diagnoses were histologically confirmed. There were 120 patients with CT scans, 31 patients with MRI and four patients with both of them. The locations of the tumors were as follows: (a) 116 parotid glands; (b) 23 submandibular glands; and (c) eight minor salivary glands.
The CT scans were performed using various scanners (GE HiSpeed, GE 9800Q, GE Medical Systems, Milwaukee, WI and Siemens Somatom Plus-S, Siemens AG, Elangen,
Histologic findings
On reviewing 147 patients, 136 were found to have neoplastic lesions (91 benign and 45 malignant tumors). The others were seven inflammatory disease and four non-neoplastic cysts.
Histologic diagnoses in the group of benign tumors were as follows: (a) pleomorphic adenoma (n=63, including five recurrent cases); (b) Warthin’s tumor (n=23); (c) monomorphic adenoma (n=3) and others. Mucoepidermoid carcinoma was the most frequent primary malignant salivary gland tumor (n=11) and acinic cell carcinoma
Discussion
In this study, both of CT scan and MRI were excellent in delineating the lesions. Both modalities can show us the exact intra- or extraglanduar location of the tumor or extension into the adjacent parapharyngeal space. Some studies have suggested MRI was the choice for evaluation of major salivary gland tumor 2, 3, 4because MRI can provide images of coronal and sagittal orientations, which is one of the advantages of this modality over CT scan.
According to the results of this study, however, CT
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Diagnosis and Management of Pathological Conditions
2023, Journal of Oral and Maxillofacial SurgeryRadiomics-based comparison of MRI and CT for differentiating pleomorphic adenomas and Warthin tumors of the parotid gland: a retrospective study
2021, Oral Surgery, Oral Medicine, Oral Pathology and Oral RadiologyThe diagnostic role of ultrasonography, computed tomography, magnetic resonance imaging, positron emission tomography/computed tomography, and real-time elastography in the differentiation of benign and malignant salivary gland tumors: a meta-analysis
2019, Oral Surgery, Oral Medicine, Oral Pathology and Oral RadiologyCitation Excerpt :Table I presents the relevant data of the included publications. With regard to the 38 eligible trials,4,9,13–48 7 studies described diagnostic performance of ultrasonography,15,18,19,22,26,33,36 6 of CT,23,24,28,30,32,35 15 of MRI,23,28,35,37–48 9 of PET/CT,9,20,24,25,29–32,34 and 7 of RTE.4,13,14,16,17,21,27 In all, 2753 salivary gland tumors were analyzed, and the reports of ultrasonography, CT, MRI, PET/CT, and RTE imaging modalities included 573, 397, 900, 417, and 584 patients, respectively.
Diagnosis and Management of Pathological Conditions
2017, Journal of Oral and Maxillofacial SurgeryAccuracy of diagnosis of salivary gland tumors with the use of ultrasonography, computed tomography, and magnetic resonance imaging: A meta-analysis
2015, Oral Surgery, Oral Medicine, Oral Pathology and Oral RadiologyCitation Excerpt :One hundred and two articles were identified in the literature databases, and 73 articles were excluded after reading their abstracts. According to the inclusion and exclusion criteria, 10 articles were excluded, and only 19 articles could be used for analysis,16-32 as described in detail in Figure 1. With the QUADAS tool, 8 articles were evaluated as high-quality articles, 10 articles were deemed medium quality, and only 1 article was of low quality.
Ultrasound and computed tomography features of primary acinic cell carcinoma in the parotid gland: A retrospective study
2014, European Journal of RadiologyCitation Excerpt :Furthermore, 40 (83%) lesions showed poor vascularization, which confirmed the above conclusion. A lobular or irregular contour with poor tumor margin on CT images has been reported to be a clear indicator of malignancy [21], while the pattern of contrast enhancement, cystic degeneration, calcification and necrosis/hemorrhage were not significant indicators of malignant lesions. In our study, 19 (54%) lesions were of regular shape and 24 (69%) had a well-defined border on CT images; these findings suggested the presence of benign AciCC.