Benign lymphoepithelial parotid lesions in HIV-positive patients: spectrum of findings at gray-scale and Doppler sonography.

Abstract

Benign lymphoepithelial lesions are intraparotid nodules that develop as an early manifestation of HIV infection. The purpose of this study was to describe the spectrum of sonographic and Doppler findings of benign lymphoepithelial lesions in HIV-positive patients and to assess whether these findings are specific for the diagnosis of such lesions. Nine HIV-positive patients with swelling of the parotid gland caused by single or multiple parotid nodules were evaluated. Fourteen nodules were identified sonographically and proved to be benign lymphoepithelial lesions at cytologic examination. They were assessed with gray-scale, duplex, color Doppler, and power Doppler sonography. For each nodule, the echogenicity, grade and pattern of vascularity, and spectral tracings were evaluated. Benign lymphoepithelial lesions manifested as parotid nodules with a wide spectrum of sonographic appearances, ranging from simple cysts to mixed masses with predominantly solid components. Cystic lesions (10/14) were not purely anechoic; they had an internal network of thin septa supplied by vessel pedicles and, in four of 10 cases, a solid mural nodule. On the other hand, mixed nodules (4/14) had a higher conspicuity of solid tissue and thicker stromal septa, thus resembling a parotid neoplasm more than a cyst. The overall grade of vascularity of benign lymphoepithelial lesions varied from avascular to intensely hypervascular. Generally, mixed nodules were more hypervascular than were the cystlike ones. Spectral analysis showed slow velocity (peak systolic velocity range, 8-28 cm/sec; mean, 20 20 cm/sec) and low impedance (resistive index range, 0.36-0.70; mean, 0.57) arterial flows. The spectrum of sonographic and Doppler features of benign lymphoepithelial lesions in HIV-positive patients is broad. Sonographic findings are non-specific for the diagnosis of such lesions, especially in cases of mixed solid-cystic isolated nodules.