[Prognostic value of granular pattern of growth hormone secreting tumors].

Background: Classification of growth hormone (GH) - secreting tumors by the granular pattern might predict their clinical behavior in acromegalic patients. There are several other prognostic factors.

Aim: To compare the features at presentation and cure rates of patients with GH secreting tumors according to the granular pattern, and to define independent prognostic factors for surgical treatment in these patients.

[Study of resistance to chemotherapy mediated by ABC transporters in biopsies of glioblastoma multiforme].

Background: Mortality rate is dramatically high in high grade brain tumors. The presence of multiple drug resistance transporters in glioblastoma multiforme, has contributed largely to the poor efficacy of targeted therapy against cancer in the central nervous system.

Aim: To analyze the percentage of survival and mortality of patients with glioblastoma multiforme in a cohort of patients in Chile and to co-rrelate the chemo-resistance of these cells with the expression level of multiple drug resistance transporters.

Primary pituitary lymphoma in immunocompetent patient: diagnostic problems and prolonged follow-up.

Primary pituitary lymphoma in immunocompetent patients is a rare disease and has been described in less than 20 cases. Moreover, low-grade lymphomas constitute only 3% of all primary central nervous system lymphoma. The objective of this report is to report a low-grade primary pituitary lymphoma, diagnostic problems and to give more evidence about the evolution of this rare disease.