Tuberculosis of the parotid gland: sonographic manifestations and sonographically guided aspiration

Involvement of the parotid gland by tuberculosis (TB) is rare. If treated properly, the prognosis of TB of the parotid gland is good. In this retrospective study, we report our experience with sonography and sonographically guided aspiration in the diagnosis of parotid TB.

Over 12 years, 9 adults (mean age, 48 years) with parotid gland TB had been examined with high-resolution sonography and color Doppler sonography for their clinical problems of swelling on the mandibular angle. Sonographically guided fine-needle aspiration was done for cytologic study, stains for acid-fast bacilli, and cultures for mycobacterium.

The sonographic patterns were classified as chiefly the parenchymal type (4 patients) and chiefly the periparotid type (5 patients). The parenchymal type appeared as a diffusely enlarged, comparatively hypoechoic gland (compared with the contralateral asymptomatic gland), with or without focal intraparotid nearly anechoic zones, which might have a cavity or cavities within it. The periparotid type appeared as hypoechoic nodules located in the peripheral zone of the hyperechoic parotid gland, consistent with enlarged periglandular lymph nodes. The diagnosis of parotid TB was made in 8 of 9 patients on the basis of sonographically guided aspiration for acid-fast bacilli stains, cytologic study, and cultures for mycobacterium.

Sonographic examination contributes substantially in the diagnosis of parotid TB infection. In the presence of diffuse parotid echo pattern changes with periparotid lymphadenopathy, and with or without focal hypoechoic zones, TB infection should be differentiated. Sonographically guided fine-needle aspiration may provide further diagnostic information by means of stains, cultures, and cytologic study.