Introduction: The term idiopathic T-CD4 lymphocytopenia is used to describe a new syndrome, defined as reduced T-CD4 lymphocytes in persons with no evidence of HIV infection or other causes which would explain the immunosuppression (secondary to neoplasties, immunosuppressive treatment, hereditary immunodeficiencies, infections, etc.). The reduced number of T-CD4 lymphocytes leads to deterioration in cellular immunity and therefore this leads to a predisposition to develop tumors and opportunist infections in patients with such defects.
Clinical case: We describe a case of depletion of T-CD4 lymphocytes, associated with disseminated encephalic cryptococcosis (multiple cortical, capsulo-ganglionar, thalamic and cerebellar cryptococcomas) in a patient with no evidence of HIV infection. The case we present fulfilled diagnostic criteria for idiopathic T-CD4 lymphocytopenia, a clinical condition seldom described in this country. We discuss the pathogenic mechanisms of cryptococcosis, the different varieties of Cryptococcus neoformans and their different roles as the cause of opportunist infections in humans.
Conclusions: In view of the neurotrophism of this fungus, the neurological signs and symptoms should make one suspect the presence of Cryptococcus neoformans infection in non-HIV carriers with cellular immunity defects such as those present in idiopathic T-CD4 lymphocytopenia.