A case of microgliomatosis in a 7-year-old boy is reported. In the absence of clinically demonstrable intracranial space-occupying lesion, presenting symptoms were episodes of hyperventilation and respiratory alkalosis. Complete autopsy showed no visceral lesion. The brain tumor was not visible to the naked eye, and the diagnosis was made only after microscopic examination. This was due to the diffuse and multifocal infiltrative character of the tumor. Microgliomatosis involving the upper pons and midbrain may have produced the dysfunction of the higher central regulation of respiration. To our knowledge, association of central neurogenic hyperventilation with microgliomatosis has not been previously described.

Keywords: brain tumor, hyperventilation, microgliomatosis, respiratory alkalosis