Isolated intrathoracic presentation of Mycobacterium avium complex in an immunocompetent child

Mycobacterium avium complex (MAC) is a rare cause of isolated intrathoracic disease in the immunocompetent child; delays in diagnosis and treatment are common. The current case is an 11- month-old girl with symptoms, signs, and radiographic findings of bronchial obstruction. Comparison of this case to the literature revealed that there is a characteristic presentation of intrathoracic MAC infection in immunocompetent children (children aged 3 years or less; without exposure to Mycobacterium tuberculosis; presenting with clinical and radiographic evidence of bronchial obstruction) that should increase our index of suspicion for this diagnosis. This is particularly important since M. tuberculosis can present in a similar pattern.