Craniopharyngioma

Craniopharyngioma 

Craniopharyngiomas are tumors arising from squamous cell remnants of Rathke pouch, located in the infundibulum or upper anterior hypophysis.

Synonym

• Subset of nonadenomatous pituitary tumors

Epidemiology & Demographics

The point prevalence of this tumour is approximately 1/50,000.

Predominant Sex:

• •Both sexes are usually equally affected.
• •Craniopharyngiomas are the most common nonglial tumors in children and account for 3% to 5% of all pediatric brain tumors.

Peak Incidence:

Occurs at all ages; peak during the first two decades of life, with a second small peak occurring in the sixth decade

What are the symptoms of Craniopharyngioma?

Always present

• Abnormal hypothalamus morphology 

Very frequent Symptoms

• Cerebral calcification 
• Enlarged pituitary gland
• Hypopituitarism
• Intracranial cystic lesion
• Neoplasm of the anterior pituitary 

Frequent Symptoms

• Abnormal visual field test
• Bitemporal hemianopia
• Central adrenal insufficiency 
• Central diabetes insipidus
• Excessive daytime somnolence
• Headache
• Hypogonadism
• Increased circulating prolactin concentration 
• Low gonadotropins (secondary hypogonadism) 
• Nausea and vomiting
• Obesity 
• Papilledema
• Pituitary hypothyroidism 
• Polyuria
• Progressive visual field defects 
• Sleep disturbance
• Slow decrease in visual acuity 

Occasional Symptoms

• Cerebral ischemia
• Delayed puberty 
• Growth delay 
• Hearing impairment
• Hydrocephalus 
• Increased intracranial pressure 
• Increased susceptibility to fractures 
• Optic atrophy
• Polyphagia 
• Proportionate short stature 
• Sleep apnea
• Type II diabetes mellitus

Rare Symptoms

• Abnormality of the frontal bone
• Abnormality of the nasal bone
• Behavioral abnormality 
• Coma 
• Global developmental delay
• Intellectual disability 
• Myocardial infarction
• Postnatal growth retardation 
• Recurrent infections
• Seizures 
• Sudden loss of visual acuity 
• Vertigo

Physical Findings & Clinical Presentation

• •The typical onset is insidious and a 1- to 2-yr history of slowly progressive symptoms is common.
• •Presenting symptoms are usually related to the effects of a sella turcica mass. Approximately 75% of patients report headache and have visual disturbances.
• •The usual visual defect is bitemporal hemianopsia. Optic nerve involvement with decreased visual acuity and scotomas and homonymous hemianopsia from optic tract involvement may also occur.
• •Other symptoms include mental changes, nausea, vomiting, somnolence, or symptoms of pituitary failure. In adults, sexual dysfunction is the most common endocrine complaint, with impotence in men and primary or secondary amenorrhea in women. Diabetes insipidus is found in 25% of cases. In children, craniopharyngiomas may present with dwarfism.
• •More than 70% of children at the time of diagnosis present with growth hormone deficiency, obstructive hydrocephalus, short-term memory deficits, and psychomotor slowing.

What causes Craniopharyngioma?

Craniopharyngiomas are believed to arise from nests of squamous epithelial cells that are commonly found in the suprasellar area surrounding the pars tuberalis of the adult pituitary.

Differential Diagnosis

• •Pituitary adenoma
• •Empty sella syndrome
• •Pituitary failure of any cause
• •Primary brain tumors (e.g., meningiomas, astrocytomas)
• •Metastatic brain tumors
• •Other brain tumors
• •Cerebral aneurysm

How is Craniopharyngioma diagnosed?

Laboratory Tests

• •Hypothyroidism (low FT₄, FT₃ with high thyroid-stimulating hormone).
• •Hypercortisolism (low cortisol) with low adrenocorticotropic hormone.
• •Low sex hormones (testosterone, estriol) with low follicle-stimulating hormone and luteinizing hormone.
• •Diabetes insipidus (hypernatremia, low urine osmolarity, high plasma osmolarity).
• •Prolactin may be normal or slightly elevated.
• •Pituitary stimulation tests may be required in some cases.

Imaging Studies

• •MRI or head CT if MRI is contraindicated. MRI features include a multicystic and solid enhancing suprasellar mass. Hydrocephalus may also be present if the mass is large. CT usually reveals intratumoral calcifications.
• •Visual field testing for bitemporal hemianopsia.
• •Skull film may show:
  • 1.Enlarged or eroded sella turcica (50%).
  • 2.Suprasellar calcification (50%).

How is Craniopharyngioma treated?

General Treatment

• •Traditionally, surgery has been the main treatment for craniopharyngioma. However, radiation treatment instead of surgery may be an option in selected cases.
• •Surgical resection (curative or palliative):
  • 1.Transsphenoidal surgery for small intrasellar tumors.
  • 2.Subfrontal craniotomy for most patients.
• •Overall prognosis is good with 80% to 90% chance of permanent cure.
• •Postoperative radiation.
• •Intralesional³²P irradiation or bleomycin for unresectable tumors. Long-term complications of radiation include secondary malignancies, optic neuropathy, and vascular injury.

Prognosis of Craniopharyngioma

• •Overall prognosis is good with 80% to 90% chance of permanent cure.
• •Operative mortality rate: 3% to 16% (higher with large tumors).
• •Postoperative recurrence rate: <20% of cases after total resection and 60% of cases after subtotal resection. Most recurrences occur within the first 2 yr after surgery.
• •5-yr and 10-yr survival: 88% and 76%, respectively, with surgery and radiation.
• •The most important factors that correlate with prognosis are the extent of resection and postoperative radiation.
• •Long-term posttreatment hormonal, visual, and neurologic problems occur in a significant percentage of patients.

Overall, the 5 year survival rate is 80%, though this can be associated with marked morbidity (hypothalamic dysfunction, altered neuropsychological profile).