Parotid mycobacteriosis is frequently caused by Mycobacterium tuberculosis in advanced AIDS

Tuberculosis is one of the leading infectious diseases in the world, with more than 2 million new cases annually. It is one of the main causes of death of human immunodeficiency virus (HIV)-positive patients, involving multiple organs and particularly the lungs. Nevertheless there are few consistent studies about tuberculosis involving the parotid of HIV patients. The objective of this work was to describe the histological and immunohistochemical characteristics of 10 cases of mycobacteriosis involving the parotid of autopsied patients with advanced acquired immunodeficiency syndrome (AIDS), including identification of the Mycobacterium species.

Detection of 'M. tuberculosis complex' was performed by polymerase chain reaction (PCR) and ligase chain reaction (LCR) and Mycobacterium avium by PCR.

All cases showed involvement of intraparotid lymph nodes, but the glandular parenchyma was affected in only three cases. Most of the cases (80%) presented a chronic non-caseating granulomatous inflammation, and in two cases predominated foamy macrophages, full of bacteria, and no granuloma formation. In areas of mycobacteriosis, macrophages predominated followed by TCD8, B and TCD4 lymphocytes. All cases were infected by Mycobacterium genus and 'M. tuberculosis complex' was detected in five cases by LCR and in eight by PCR, while M. avium was positive in one case only, which was also positive for M. tuberculosis.

Parotid mycobacteriosis in advanced AIDS is characterized by intraparotid lymph node non-caseating inflammatory granulomatous lesion, caused mainly by M. tuberculosis.