[Fungus imitators in the newborn brain].

Morphology of the basophilic fibers erroneously considered by some authors as the fungus mycelium found in 4 newborns with periventricular leukomalacia is studied at the light- and electron microscopic level. Differential diagnosis between fungi and these structures which, in the authors opinion, are the damaged non-myelinated axons, including those with mineralization, is presented.