Figure 16. Longitudinal section through the right parotid gland in a middle-aged male who presented with acute onset of painful parotid swelling. The gland appears hypoechoic and inflamed and there is a poorly defined hypoechoic mass in the superficial lobe. The appearances are suggestive of parotid abscess formation and this was confirmed following ultrasound-guided aspiration of 5 ml of pus from the lesion from which viridans streptococcus was isolated.