Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis. It typically affects the lungs but can also affect other sites which is known as extra pulmonary tuberculosis (EPTB). Tuberculous Lymphadenitis constitutes 20-40% of EPTB. Commonly involved superficial lymph nodes (LN) include those in posterior and anterior cervical chains or the suprascapular fossae, but others like submandibular, periauricular, inguinal and axillary groups may also be involved.
TB is a major health problem in developing and under-developed countries, and low and middle income countries (LMIC), specifically Sub Sharan African countries pay a heavy price in terms of TB morbidity and mortality. The situation is aggravated by co-infection with HIV. According to WHO, over 80% of the reported TB cases occurred globally in 22 high-burdened, developing countries (3). For example, annual incidence of TB estimated in the Central Africa Republic in 2009 was 345 per 100,000 and a death rate of 113 per 100, 000. The incidence rate of this disease in Ethiopia in 2014 was 224 per 100, 000 inhabitants. A one-year retrospective data set from the largest hospital in Ethiopia in 2017 shows that, about 1,226 are positive for TB lymphadenitis that were diagnosed by the routine stain.
Fine Needle Aspiration Cytology (FNAC) plays a vital role in confirmatory diagnosis of lymphadenopathy and tuberculous adenitis due to its cost effectiveness, simplicity, accuracy, and safety. It reduces the need for unnecessary surgery. However, in Ethiopia and of course other countries of the Sub-Saharan region, pathologists diagnose the smeared slide that has been stained with only a routine type of staining, either Wright or Giemsa staining. This practice narrows the probability of finding the diagnosis.
Performing a special stain (AFB), combined with rapid molecular diagnostic tests (Genexpert), prior to the routine staining of slides, could improve the diagnosis of tuberculous lymphadenopathy and provide valuable information for appropriate treatment.
Written by Giorgis Yeabyo, MS
1. Gemechu A. Fekade Y. Negash W. Magnitude of Tuberculosis Lymphadenitis in Hawassa University Referral Hospital, Southern Ethiopia. American Journal of Health Research. 2015; 3(2):116-120.
2. P.R.Gupta. Difficulties in managing lymph node tuberculosis. Lung India.2004; 21 : 50-53.
3. Fanny et al. Fine-needle aspiration for diagnosis of tuberculous lymphadenitis in children in Bangui, Central African Republic. BMC Pediatrics 2012 12:191.
4. Zuber A. Syed S. Role of Tuberculin Test, FNAC, and Elisa in the Diagnosis of Tuberculous Lymphadenitis. JIACM 2003; 4(4): 292-5