Sonography of nonneoplastic disorders of the salivary glands

The applicability of ultrasound in the diagnosis of inflammatory and obstructive diseases of the major salivary glands: a scoping review

OBJECTIVES

The purpose of the present scoping review was to determine the contribution of ultrasound images in the diagnosis of inflammatory and obstructive diseases of the major salivary glands (MSGs).

METHODS

A search of studies of ultrasonographic assessments of human samples was performed in several electronic databases and grey literature up to July 2021. The extracted data were the examined MSG; the diagnostic value of ultrasound (sensibility, specificity, positive- and negative predictive value, accuracy); features of lesions, including number, echogenicity, echotexture, form, margins, size, posterior acoustic aspect, and location; and related clinical information, such as swelling, palpation, sensible to pain, salivation, lymph nodes, recurrence, duration, and causes.

RESULTS

After verifying the eligibility criteria, 90 articles focused on detecting inflammatory, and obstructive diseases of the MSG were gathered, with variable study designs and size samples. A wide variety of pathologies were assessed, including sialolitiasis (n = 45), acute sialadenitis (n = 30), chronic sialadenitis (n = 25), granulamatous diseases (n = 15), Kuttner's tumor (n = 11), juvenile recurrent parotitis (n = 9), abscess (n = 7), post-radiotherapy sialadenitis (n = 6), sialadenosis (n = 9), abscess (n = 7), IgG4-related disease sialadenitis (n = 5), HIV-sialadenitis (n = 4), obstructive sialadenitis (n = 3), iodinated contrast-induced sialadenitis (n = 2), and pneumoparotitis (n = 1). Most studies were case reports or series of cases. Few studies exhibited data about the accuracy of ultrasound in detecting MSG diseases.

CONCLUSIONS

The present scoping review concluded that ultrasound aspects of different MSG pathologies are similar but contribute to their differential diagnosis and can be considered as a valuable initial method for assessing the MSG of adults and children.

Ultrasound in Inflammatory and Obstructive Salivary Gland Diseases: Own Experiences and a Review of the Literature

Background: Ultrasound is established as a diagnostic tool in salivary glands for obstructive diseases such as sialolithiasis and tumors. Concerning inflammatory diseases and in non-sialolithiasis-caused obstruction, much fewer data are available. In recent years, technical development has allowed a better assessment of the gland parenchyma, and knowledge about intraductal pathologies has increased considerably, which has provided new insights and a new interpretation of ultrasound findings. Objectives: To provide a comprehensive review of the literature that includes our own experiences and to point out the state of the art in ultrasound in the diagnostics of inflammatory and obstructive salivary gland diseases, taking adequate techniques and recent technical developments into consideration. Data sources and study eligibility criteria: A systematic literature search was performed in Pubmed using various specific key words. Results: According to the literature results, including our own experiences, ultrasound is of value in up to >90% of cases presenting with inflammatory and/or obstructive diseases. Technical developments (e.g., elastography) and the application of modified ultrasound techniques (e.g., transoral ultrasound) have contributed to these results. Today, ultrasound is considered a first-line diagnostic tool in these diseases. However, in some inflammatory diseases, the final diagnosis can be made only after inclusion of the anamnesis, clinical symptoms, serologic blood tests, or histopathologic investigation. Conclusions: Ultrasound can be considered as a first-line diagnostic tool in obstructive and inflammatory salivary gland diseases. In obstructive diseases, it may be sufficient for diagnostics in >90% of cases. In inflammatory diseases, ultrasound is at least an excellent screening method and can be used to establish the diagnosis in cases of an early suspicion. In all diseases ultrasound can contribute to better management and can be used for monitoring during follow-up.

In-Office Ultrasonographic Evaluation of Neck Masses/Thyroid Nodules

Office-based ultrasonography is increasingly becoming an integral part of an otolaryngology-head and neck surgery practice. A thorough knowledge of the ultrasonic appearance of normal and abnormal pathology are key for performing/interpreting office-based head and neck ultrasonography. A focused but systematic approach allows for efficient and effective office-based head and neck ultrasonography. Office-based ultrasonography also allows for imaging procedures expanding the otolaryngologist's armamentarium. Ultrasound-guided fine needle aspiration (USgFNA) is an integral part of clinician-performed ultrasonography because it allows cytologic diagnosis of suspicious lesions. Understanding the successful techniques and pitfalls in this procedure are critical for the otolaryngologist performing USgFNA.

An evaluation of efficacy of ultrasonography in the diagnosis of head and neck swellings

OBJECTIVE

The aim of this study was to evaluate the efficacy of ultrasonography in the diagnosis of swellings in the head and neck regions.

METHODS

For this study, 70 cases with clinically obvious swellings in head and neck regions were selected randomly. The ultrasonographic features considered were shape, boundary, echo intensity, ultrasound architecture of lesion, posterior echoes and ultrasound characteristic of tissues. Intergroup comparisons were made between four different types of swellings: inflammatory; cystic; benign; and malignant.

RESULTS

A comparison was made between benign and malignant neoplasms, and the criteria of boundary, echo intensity and ultrasound architecture of lesions are statistically significant as the P-value is <0.05. The comparison of inflammatory swellings and malignant neoplasms shows that criteria of boundary and ultrasound architecture of lesions are statistically significant. The comparison of cystic swellings and benign neoplasms concluded that only the criterion of ultrasound characteristics of tissues is statistically significant. The comparison of inflammatory swellings and benign neoplasms shows that the criteria of boundary and echo intensity are statistically significant. The comparison of inflammatory swellings and cystic swellings concluded that the criteria of boundary, shape, echo intensity, posterior echoes and ultrasound characteristics of tissues are statistically significant. The comparison of cystic swellings and malignant neoplasms concluded that the criteria of ultrasonography, boundary, shape, echo intensity, ultrasound architecture of lesion, posterior echoes and ultrasound characteristics of tissues are statistically significant as the P-value is <0.05.

CONCLUSION

It can be concluded that clinical diagnosis had a sensitivity and accuracy of 85.7% and ultrasonographic diagnosis had a sensitivity and accuracy of 98.5%.

Extracorporeal lithotripsy techniques for salivary stones

Over the past 20 years, development of minimally invasive therapies has led to the use of extracorporeal shock wave lithotripsy (ESWL) to treat salivary stones. The two main energy sources are piezoelectric and electromagnetic extracorporeal lithotripsy. Both have the aim of fragmenting the stones. ESWL is considered the treatment of choice for all parotid calculi and submandibular perihilar or intraparenchymal stones of less than 7 mm. Continuous ultrasonographic monitoring during the procedure reduces the number of untoward effects. The main limitations are the need for multiple sessions and residual stone fragments inside the duct system.

Major and minor salivary gland tumors

Malignant salivary gland tumors are rare. The most common tumor site is the parotid. Aetiologic factors are not clear. Nutrition may be a risk factor, as well as irradiation or a long-standing histologically benign tumor that occurs at youth. Painless swelling of a salivary gland should always be considered as suspicious, especially if no sign of inflammation is present. Signs and symptoms related to major salivary gland tumors differ from those concerning minor salivary gland tumors, as they depend on the different location of the salivary gland. Surgical excision represents the standard option in the treatment of resectable tumors of both major and minor salivary glands. Neutron, heavy ions or proton radiotherapy may be a treatment option for inoperable locoregional disease. Surgery, irradiation or re-irradiation are treatment options for local relapse, whereas radical neck dissection is indicated for regional relapses. Metastatic disease may be either treated with radiotherapy or palliative chemotherapy, depending on the site of metastases. For highly selected patients the employment of anti-androgen therapy is indicated.

US of the major salivary glands: anatomy and spatial relationships, pathologic conditions, and pitfalls

Ultrasonography (US) is useful for differential diagnosis of diseases of the salivary glands. In acute inflammation, salivary glands are enlarged and hypoechoic with increased blood flow; they may contain multiple small, oval, hypoechoic areas. In chronic inflammation, salivary glands are normal sized or smaller, hypoechoic, and inhomogeneous. Sialolithiasis appears as markedly hyperechoic lines or points with distal acoustic shadowing. Sialosis appears as enlarged hyperechoic glands without focal lesions or increased blood flow. The US features of advanced Sjögren syndrome include inhomogeneous salivary glands with scattered small, oval, hypoechoic or anechoic areas, usually well defined, and increased parenchymal blood flow. Pleomorphic adenomas are usually hypoechoic, well-defined, lobulated lesions with posterior acoustic enhancement that may contain calcifications; Warthin tumors are usually oval, hypoechoic, well-defined lesions that often contain anechoic areas and are often hypervascularized. Malignant neoplasms of the salivary glands may have irregular shapes, irregular borders, blurred margins, and a hypoechoic inhomogeneous structure or may have a benign appearance. Salivary gland cysts have well-defined margins, anechoic contents, posterior acoustic enhancement, and no internal blood flow. However, US appearances of some diseases may overlap, thus producing diagnostic pitfalls.

Sonographic diagnostic criteria for screening Sjögren’s syndrome

OBJECTIVE

The objective of this study is to establish readily applied sonographic diagnostic criteria for Sjögren's syndrome.

STUDY DESIGN

Sonographic images of 79 cases of previously suspected Sjögren's syndrome (including 43 actual cases) were analyzed retrospectively for the following characteristic features: (1) multiple hypoechoic areas, (2) multiple hyperechoic lines or spots, (3) multiple hypoechoic areas surrounded with hyperechoic lines or spots, and (4) obscuration of the gland configuration. Logistic regression analysis was used to extract valuable sonographic findings. Sonographic images of 80 prospective patients (of whom 48 proved to have Sjögren's syndrome) were scored prospectively using selected features to verify the usefulness of the established criteria.

RESULTS

Three sonographic findings in parotid and submandibular glands were selected by logistic regression analysis and retrospective and prospective patients compared. Experienced observers could differentiate positive cases of Sjögren's syndrome from negative controls to a highly significant degree. Findings correlated very well with sialographic grading.

CONCLUSION

Sonography can be substituted for sialography when applying the selected criteria in screening for Sjögren's syndrome.

Multiple sialolithiasis in the parotid gland with Sjögren's syndrome and its sonographic findings--report of 3 cases

We present 3 cases of Sjögren's syndrome in which multiple sialolithiasis were observed in the parenchyma of the parotid gland. The sonographic examinations showed microliths that were observed as hyperechoic spots. Some of the microliths were accompanied with comet sign, however most of them showed no particular posterior echoes. None of them showed acoustic shadows, which are normally observed in cases with sialolithiasis. We were able to prove that some of the hyperechoic spots observed sonographically in patients with severe Sjögren's syndrome were microliths. Although these multiple microliths are rarely detected, they may exist potentially in higher frequency in patients with severe Sjögren's syndrome.

Using ultrasonography to diagnose Sjögren's syndrome

Ultrasonographic imaging of the parotid gland parenchyma represents a relatively new and extremely useful procedure that was applied in this study of patients with secondary Sjögren's syndrome, or SS. A nonhomogeneous parotid gland and hypoechoic areas were apparent in the sonograms of nine consecutive SS patients who were examined using this simple, noninvasive technique.

Ultrasonographic biometry in salivary glands

Specifications about the size of healthy salivary glands are not available to date. Therefore, we determined the size of the submandibular and the parotid glands by ultrasonography in 50 subjects (25 men, 25 women, mean age 45 y, range 20-68) with no history of disease affecting the salivary glands. The subjects were equally distributed concerning gender and age. Body weight did not differ more than 20% from the ideal weight following Broca's formula (mean body weight 71 kg, range 46-95 kg). In the submandibular glands we found an anterior-posterior length of 35 mm +/- 5.7 mm, a paramandibular dimension to the depth of 14.3 mm +/- 2.9 mm and a dimension in frontal scanning of 33.7 mm +/- 5.4 mm. The parotid glands were measured 46.3 mm +/- 7.7 mm in the axis parallel to the mandibular ramus and 37.4 mm +/- 5.6 mm in the transversel axis. The dimension of the parotid parenchyma was measured with 7.4 mm +/- 1.7 mm lateral to the mandible and 22.8 mm +/- 3.6 mm dorsal to the mandible. No statistically significant difference to the 5%-level was found concerning gender. The dimension of the parotid glands correlated statistically significantly with body weight (p = 0.03). This correlation was not found in the dimension of the submandibular glands. Age did not correlate with the dimension of salivary glands. Results of the submandibular glands were compared with volume measurements of submandibular glands from cadavers.

Ultrasonographic biometry in normal salivary glands

Specifications about the sizes of normal salivary glands are not available. We used ultrasonography to determine the sizes of the submandibular and parotid glands in 50 subjects, who were not suffering from diseases of the salivary glands. Volunteers were distributed equally concerning sex and age. Body weight did not differ more than 20% from ideal weight. Dimensions of the submandibular glands were: anterior-posterior length, 35 +/- 5.7 mm; paramandibular extension to gland depth, 14.3 +/- 5.7 mm; extension in frontal scanning, 33.7 +/- 5.4 mm. The parotid glands measured 46.3 +/- 7.7 mm in the axis parallel to the mandibular ramus and 37.4 +/- 5.6 mm in a transverse axis. The extensions of the parotid parenchyma were 7.4 +/- 1.7 mm lateral to the mandible and 22.8 +/- 3.6 mm dorsal to the mandible.