The diagnostic pathway to lymph node excision biopsy in an HIV- and tuberculosis-endemic region

In the HIV/tuberculosis endemic Western Cape public care setting, diagnostic consideration of patients with persistent lymphadenopathy focuses on extra-pulmonary tuberculosis (EPTB), delaying diagnosis of other infectious or malignant causes of lymphadenopathy.

To evaluate the diagnostic pathways of patients investigated for lymphadenopathy at Groote Schuur Hospital.

A retrospective review of patients undergoing lymph node excision biopsy was conducted to correlate test selection and results prior to biopsy with final patient diagnosis and assess the impact of pre-biopsy pathways on diagnostic delay.

Of 86 patients undergoing excision biopsy, 61 (71%) had no previous diagnosis to explain the lymphadenopathy. Extra-pulmonary tuberculosis was the commonest diagnosis (24.6%, 15/61), followed by lymphoma (21.3%, 13/61), and metastatic cancer (14.8%, 9/61). Median time from presentation with lymphadenopathy to first excision biopsy was 55 days (interquartile range [IQR] 22-106). Fine needle aspiration (FNA) cytology of lymphadenopathy was performed in 30 out of 61 (49%) of the patients and repeated in a third of these, while smear for acid-fast bacilli and culture for Mycobacterium tuberculosis were infrequently performed, and the GeneXpert MTB/RIF assay on FNA was never performed. FNA cytology was non-diagnostic in all seven patients with lymphoma in whom it was performed.

In patients with lymphadenopathy, we demonstrate how poorly structured diagnostic pathways contribute to unnecessary healthcare utilisation and diagnostic delay in treatable conditions. Providing early access to biopsy after appropriate workup ensures accurate diagnosis of unexplained lymphadenopathy.