Lipomas of the mesencephalic tectum and rostral pons associated with sleep apnea syndrome.

Two patients with mixed sleep apnea and autopsy-documented lipomas of the mesencephalic tectum and rostral pons are presented. Microscopically, the locus ceruleus was unilaterally invaded by a tumor in one case and may have been compressed in the other. Adipocytes and fibrous tissue were present adjacent to pial surfaces and around small blood vessels within the parenchyma. There was prominent astrogliosis in the adjacent neuropil. Although respiratory control is a complex, multifocal phenomena, these findings raise the possibility that the locus ceruleus or adjacent brain stem regions may be affected in some instances of sleep apnea.