Background: Bacillus Calmette-Guérin (BCG) vaccination is recommended for newborn infants worldwide to prevent tuberculosis. However, complications do occur inevitably in a very low rate, among which the most serious is disseminated disease. The disseminated bacillus Calmette–Guérin disease is a rare disease with high fatality, and can be seen among persons with an underlying immunodeficiency. Case presentation: We report a 4-month-old male infant presenting with recurrent fever, an isolated left axillary massand swelling at the site of BCG inoculation. The cellular immune function analysis showed that the value of CD4/CD8 was 0.994, indicating the existence of immunodeficiency.The results of blood culture and throat swab culture showed conditional pathogen infection. He died of cardiopulmonary failure.
Conclusion: In this case, necropsy played a significant role in the final diagnosis of disseminated pulmonary tuberculosis.