Aetiology of peripheral lymphadenopathy in adults: Analysis of 1724 cases seen at a tertiary care teaching hospital in southern India

Background. In patients presenting with peripheral lymphadenopathy, excision biopsy of the most accessible lymph node provides material to establish an early diagnosis, and is important in the management of these patients. Methods. A retrospective study was done of 1724 lymph node biopsy specimens obtained from adult patients and submitted for histopathological examination over a 12-year period. Results. About one-third (n=614; 35.6%) of these patients had non-specific lymphadenitis. This included a heterogeneous group of disorders comprising benign follicular hyperplasia, reactive hyperplasia, marked follicular hyperplasia and reactive sinus histiocytosis. Tuberculosis lymphadenitis (n=540; 31.3%) and malignancy (n=447; 25.9%) were the other common causes. Of the 540 patients with tuberculosis lymphadenitis, the human immunodeficiency virus (HIV) status was tested in 424 (78.5%) patients; of these, 34 patients (8%) were HIV-seropositive. Epithelioid granulomas with caseation necrosis were more frequently seen in HIV-seronegative patients compared with HIV-seropositive ones (chi(2) = 54.66; p < 0.001). In HIV-seropositive patients, multiple sites of lymph node involvement (chi(2) =40.597; p < 0.001), suppurative type with adjacent necrosis and panniculitis (chi(2) =68.128; p < 0.001), and non-reactive histological types (chi(2) = 109.234; p < 0.001) were more commonly seen compared with HIV-seronegative patients. Kikuchi-Fujimoto disease (n=36), Kimura disease (n=7), Rosai-Dorfman disease (n=6), were rare aetiological causes that have been infrequently reported from India. Conclusion. Awareness of the characteristic histopathological findings and uncommon aetiological causes of peripheral lymphadenopathy may spare patients from unnecessary evaluation and treatment. In HIV-positive patients, lymph node tuberculosis may be histopathologically unusual and may be suppurative or non-reactive in nearly one-third of patients.