Pediatric craniopharyngiomas: magnetic resonance imaging assessment for hypothalamus-pituitary axis dysfunction and outcome prediction.

BACKGROUND

In adamantinomatous craniopharyngiomas, tumor topographical categories, cystic component volume, and magnetic resonance signal intensity may impact prognosis.

OBJECTIVE

To identify magnetic resonance imaging (MRI) variables associated with pituitary-hypothalamic axis dysfunction and predictive of outcome in children with cystic adamantinomatous craniopharyngiomas.

MATERIALS AND METHODS

We evaluated 40 preoperative MRIs of adamantinomatous craniopharyngiomas to classify tumor topography, volume, and signal intensity of the cystic components and peritumoral edema. Volumes and normalized signal intensity minimum values were extracted from coronal T2-weighted images (nT2). Radiological variables were compared to pituitary-hypothalamic axis dysfunction-related clinical data and surgical outcomes.

RESULTS

Adamantinomatous craniopharyngiomas were categorized into five topographic classes (12 patients, sellar-suprasellar; seven patients, pseudo-intraventricular; six patients, strict intraventricular; 14 patients, secondary intraventricular; one patient, not strict intraventricular). All cases exhibited a predominant (30 patients, 80%) or total (10 patients, 20%) cystic tumor component and displayed low nT2 percentage values compared to cerebrospinal fluid (42.3% [interquartile range 28.4-54.6%]). Significant associations between tumor topographic classes and pituitary dysfunction (P<0.001), and between peritumoral edema and hypothalamic dysfunction (P<0.001) were found. Considering extent of surgical removal and tumor relapse, volume of the cystic tumor component displayed a positive correlation (P=0.002; r=0.48; P=0.02; r=0.36), while nT2 intensity values exhibited a negative correlation (P=0.01; r= - 0.40; P=0.028; r= - 0.34).

CONCLUSION

Severe hypothalamic-pituitary axis dysfunction is associated with tumors along the pituitary stalk and peritumoral edema. Tumor invasion of the third ventricle, tight adherence to the hypothalamus, larger volumes, and lower nT2 intensity of the tumor cystic component are independent predictors of extent of adamantinomatous craniopharyngioma excision and recurrence.