Background and objectives: Patients with major salivary gland pathology may present with a suspected mass, diffuse glandular enlargement or symptoms of obstruction and inflammation. Various imaging modalities are available for assessing the major salivary glands, however, in recent years ultrasound has become the initial investigation of choice. Sonomorphological features may correlate to certain pathological conditions thereby allowing a diagnosis to be made on ultrasound findings alone. The objective of this study is to assess the value of ultrasound in differentiating between inflammatory, benign and malignant pathology affecting the major salivary glands. Methods: Patients who had excision of any of the major salivary glands over a 5 year period at a single institution were identified and the notes retrospectively reviewed. Only those with a pre-operative ultrasound and histologically confirmed diagnosis were included. All ultrasound scans were undertaken and reported by a single radiologist. Reports stating more than one type of lesion (e.g. benign or malignant neoplasm) were classified as ‘unclear’.
Results: A total of 130 patients (age range of 18–88 years) were included, all of which had a single ultrasound undertaken. The majority were for benign neoplasms of the parotid gland. A third stated unclear findings; most commonly this was due to an inability to differentiate between a benign and malignant neoplasm. For the remaining two thirds the sensitivity, specificity, negative predictive value, positive predictive value and accuracy for inflammatory pathology was 83%, 96%, 87%, 94% and 90%, 74%, 84%, 80%, 78% and 80% for benign neoplasms and 44%, 86%, 93%, 27% and 82% for malignant neoplasms.
Conclusion: Although ultrasound may be used as an initial investigation for major salivary gland pathology it should not be considered the sole diagnostic investigation, and findings should be used to guide further imaging and sampling modalities.
Key words: ultrasound; salivary glands