RESUMO
A fatal case of primary amoebic encephalitis (PAM) in a 20 year old boy, a proven case of acute leukemic leukemia (ALL) type L2, in remission is described. No history of swimming could be elicited. The clinical presentation, the isolation of the amoeba from the cerebrospinal fluid (CSF), the poor response to amphotericin B, and the ultimately fatal outcome are all consistent with the diagnosis of PAM. On the basis of its ability to grow at temperature 42ºC and 45ºC, morphology of trophozoite, and the presence of flagellate forms in CSF, the amoeba was identified as Naegleria fowleri. Other drugs used in combination with amphotericin B are tetracycline, rifampicin, and miconazole. A possibility of PAM should always be considered in all cases of acute purulent meningoencephalitis in which no bacteria or fungus are found.