Persistent Axillary Lymphadenitis in a Toddler PostBCG vaccination: A Case Report

Bacillus Calmette-Guérin (BCG) vaccine, a live attenuated vaccine derived from Mycobacterium bovine, has been used as a part of routine immunization programs. One of the complications of this vaccination is BCG adenitis, which is the enlargement of the regional lymph node in the axillary or supraclavicular area. Normally, this condition resolves approximately 6 weeks after vaccination, and persistent BCG adenitis is rarely seen in children with immunocompetence. Herein, a 5-month-old boy presented with complaints of left axillary lymphadenopathy after 2 weeks of BCG vaccination. Ultrasonography revealed a nontender mobile lymph node measuring approximately 2.5 × 2 cm, which persisted beyond 12 months of age. The parents insisted on removing the swelling surgically at the age of 18 months as it did not resolve on its own. The lesion was removed and sent for HPE examination, acid-fast bacilli (AFB) staining, and GeneXpert for Mycobacterium tuberculosis (MTB). In the current case, the HPE revealed epithelioid cell granulomatous lesions, with no AFB or necrosis. The GeneXpert MTB/RIF (Cepheid) test was positive, which detected the MTB complex (including MTB and BCG), suggestive of BCG adenitis without active tuberculosis. This case shows that BCG adenitis can persist even beyond the age of 12 months. Careful history taking and timely adequate investigation along with the knowledge that GeneXpertMtb detects MTB complex will aid in the correct diagnosis.