DIENCEPHALIC SYNDROME AND DISSEMINATED JUVENILE PILOCYTIC ASTROCYTOMAS OF THE HYPOTHALAMIC-OPTIC CHIASM REGION

BACKGROUND, Diencephalic syndrome (DS) is a complex of signs and sympt oms related to hypothalamic dysfunction; its main features are emaciat ion, despite a normal or slightly diminished caloric intake, and an al ert appearance. DS has been almost exclusively described in associatio n vith space-occupying lesions of the hypothalamic-optic chiasm region , mainly juvenile pilocytic astrocytoma (JPA). A systematic diagnostic approach, including contrast-enhanced magnetic resonance imaging (MRI ) of the child's head, is rapidly expanding our knowledge of this synd rome. METHODS, The MRI findings for three children affected by DS asso ciated with biopsy-proven JPA, consecutively referred to the Pediatric Neuro-Oncology Program of the Department of Pediatrics at the Univers ity of Padua between September 1991 and January 1996, are presented in this article. The children were boys, ages 6, 7, and 18 months, respe ctively. RESULTS, In all three patients, the initial contrast-enhancin g MRIs of the head showed evidence of tumor dissemination. This findin g prompted a study of the spine, which in turn showed tumor deposits i n all three subjects. Among the 43 patients younger than 16 years with low grade astroctyoma who consecutively entered the Neuro-Oncology Pr ogram during the study period, these 3 patients were the only ones who had disseminated tumors. CONCLUSIONS, In this study, the hypothesis w as formulated that DS and disseminated hypothalamic-optic chiasm JPA t end to be more commonly associated than previously stated. This study suggests that the initial contrast-enhanced MRI of the head of a child affected by DS and hypothalamic JPA must be looked at carefully for e vidence of tumor dissemination, and that the spine must also be examin ed if the findings are positive. (C) 1997 American Cancer Society.