The right middle lobe syndrome (RML Syndrome) is serious to the extent that it can predispose to
recurrentRecurrent cystitis infection, with all the risks that accompany an infection. The
recurrentRecurrent cystitis infection may be on the basis of the middle lobe anatomy or anatomically limited local defense mechanisms, the latter possibly due to some permanent damage to the
bronchialBronchial
Bronchial adenoma membranes and their ability to resist infection, at the time of the first pneumonia.
Another explanation could be infection with an atypical organism that has responded partially to therapy but has never completely resolved since the first pneumonia. The preceding is based on the assumption that the recurrent pneumonia has been only in the RML and not scattered throughout the lungs.
If this is not the case and other parts of his lungs have been infected, a more likely possibility would be that he has either a congenital or an acquired immunodeficiency state and should be tested for it.
The definitive treatment for the RML Syndrome is surgical removal of the RML and that would have no lasting effect on his lung function or his general health in the years to come.
You may want to request a second opinion from a Pediatric Pulmonologist.
Good luck