Craniopharyngiomas account for up to 15% of the intracranial tumors in children with peak incidence rates at the age of 5–14 years. Almost 80% of these have are large cystic tumors.
Craniopharyngioma is a rare, non-malignant intracranial tumor derived from a malformation of embryonal tissue. The origin of Craniopharyngioma is debated between two hypotheses: the first describes its origin as ectodermal remnants of Rathke’s pouch; the second argues it represents a malformation of residual embryonal epithelium of the anterior pituitary gland and infundibulum.
Though benign in appearance the clinical behavior of Craniopharyngioma is aggressive, causing serious morbidity by damaging the optic chiasm, the pituitary, and hypothalamic area. The severity of symptoms and signs is directly related to the tumor’s size, position, and exact location. Disturbance of cerebrospinal fluid (CSF) flow often causes Obstructive hydrocephalus.
Initial symptoms often occur long before actual diagnosis is made in Craniopharyngioma, as the non-specific manifestations of increased intracranial pressure such as headache and nausea are often missed. Almost three-quarters of children have severe visual impairment and endocrine deficits. Growth impediment caused by hormonal disturbances involving Growth Hormone, Thyroid Stimulating Hormone and AdrenoCorticoTropic Hormone often appears as early as one year of age. Older children present with premature puberty and/or unmanageable weight gain.
Neuroimaging using CT and MR Imaging is essential for the diagnosis. Combination of solid, cystic, and calcified tumor components is an important radiological clue to its diagnosis. MRI before and after intravenous Gadolinium is the standard imaging for detection of Craniopharyngioma, but because CT is the only way to detect or exclude calcification, which is found in approximately 90% of tumors, a sellar or parasellar mass detected on MRI should be further imaged by non contrast CT for detection of calcifications.
Cystic craniopharyngiomas are frequently considered inoperable due to extensive local attachment of cyst wall to adjacent vital structures, and it was easy for the surgeon to lose contact with the extremely thin sinus cyst wall, which later resulted in tumor recurrence. The transsphenoidal approach to the sellar- suprasellar region has the advantage of minimizing disturbance to hypothalamic functions.
The ‘machine’ oil fluid that escapes on opening the dura during trannsphenoidal approach (seen in the picture above) is diagnostic of a Cystic Craniopharyngioma.
There are strong advocates of good local control for both radical surgical resection and limited surgery followed by postoperative radiotherapy. When a patient presents with a purely cystic craniopharyngioma, the management options include the stereotactic placement of a catheter to allow repeated aspiration and furthermore intracystic irradiation with radionuclide (32P or 90Y etc.)
Cystic Craniopharyngioma in childhood should be considered a chronic disease which is best managed by Team effort. Hypothalamic involvement and/or treatment-related injuries to the optic pathway and critical brain structures result in impaired physical and social functionality and severe neuroendocrine sequel.