Introduction Intra-thoracic lymphadenopathy is commonly observed in patients infected with HIV. The broad range of aetiologies and the non-specific clinical picture constitute a diagnostic challenge which has not been previously addressed. Therefore we aimed to identify the causes of mediastinal lymphadenopathy in HIV infected patients presenting to our specialist unit and to characterise their mode of diagnosis.
Methods We conducted a retrospective analytical cohort study of HIV positive patients who underwent CT scanning of the chest between January 2004 and December 2008. Each patient was followed clinically for at least 12 months.
Results 234 consecutive patients underwent chest CT in the study period. Employing the conventional CT cut-off for significant lymphadenopathy of 10 mm in short-axis, mediastinal lymphadenopathy was present in 49 (21%) patients. In these 49 patients, the mean age was 40 (range 19–69) years. 43 patients were male and 24 of the male patients were homosexual. 25 (51%) of patients were receiving antiretroviral therapy and 24 patients had a CD4 lymphocyte count below 250 cells ×106/l. A specific diagnosis was made in 42 cases. Lymphoma was the most common diagnosis with 9 cases, followed by TB with seven cases. Six patients had reactive lymphadenopathy secondary to pneumonia. There were four cases of Castleman's disease, four of malignancy and three of non-tuberculous mycobacterial infection. In total, 13 patients (31%) were diagnosed with cancer. Extra-thoracic lymphadenopathy documented by CT was present in 26 (53%) of patients, including in seven cases of lymphoma and in all cases of Castleman's disease. The diagnosis was established by histopathology in 57% of cases, by clinical follow-up in 19% and by microbiology in 7%. USS guided peripheral lymph node biopsy was the preferred biopsy method in 16 cases. Surgical biopsy was performed in seven cases and EBUS-TBNA in two cases.
Conclusions Mediastinal lymphadenopathy is common in HIV positive patients undergoing CT scanning of the thorax and can be associated with a wide range of conditions. However, the prevalence of malignancy is high in this setting, emphasising the need for a pathological diagnosis.