Craniopharyngiomas are intracranial
Skull Base Tumors that
are typically both cystic and solid in structure. They
occur most commonly in childhood and adolescence and
in adult life after age 50 years. They account for
2-4% of primary Brain tumors, 10-15% of Sellar and Suprasellar
tumors (tumors that occur in and above the Pituitary
Fossa also known as the "Sella Turcica") and
50-60% of Sellar and Suprasellar tumors, in children.
Craniopharyngiomas are usually not discovered until they
impinge upon important structures around them, and are
frequently quite large (over 3 cm), when detected. They are
histologically benign (not malignant) tumors, but they
have a tendency to become adherent to structures in and around
the Pituitary Gland and Pituitary Stalk, including the
Optic Nerves, Optic Chiasm, intracranial arteries and the
Brain itself.
Craniopharyngiomas are believed to arise from remnants
of the Craniopharyngeal duct, or Rathke's pouch, which are
developmental structures related to the primitive gut.
Embryonic cells from an incompletely "involuted" Craniopharyngeal
duct, or transformation of squamous cells in the lower infundibulum,
or anterior Pituitary Gland, may give rise to a Craniopharyngioma.
These tumors are thought to be closely related to another cystic mass,
occasionally seen in the Pituitary region called a
Rathke's Cleft Cyst.
The symptoms produced by a Craniopharyngioma, vary depending
upon the tumor's location. If it compresses the
Pituitary Stalk, or involves the area of the Pituitary
Gland itself, the tumor can cause partial, or complete
Pituitary hormone deficiency. This frequently results in one
or more of the following: growth failure, delayed puberty, loss
of normal menstrual function or sexual desire, increased sensitivity
to cold, fatigue, constipation, dry skin, nausea, low blood pressure,
and depression.
Diabetes Insipidus, is a condition associated with the
patient's production of massive volumes of urine and experiencing
unquenchable thirst, both resulting from compression of the
Pituitary Stalk resulting in a deficiency in the release of the
Anti-diuretic Hormone (ADH). (See
Pituitary Gland Tumors Patient Information
for a discussion of Diabetes Insipidus also called "DI")
Additionally, Pituitary stalk compression can result in increase
production of the hormone Prolactin, which causes breast milk
production (galactohhrea).
Visual disturbances, of different degrees of severity
(including blindness), can result if the Craniopharyngioma involves
the Optic Tracts, Optic Chiasm, or Optic Nerves.
Hypothalamic disturbances can result from involvement
of the Hypothalamus (an area in the very center of the Brain) which
may cause in obesity, increased drowsiness, temperature
regulation abnormalities, and diabetes insipidus.
Personality changes, headache, confusion, and vomiting
are among the other symptoms manifested in these patients.
The best means of visualizing a Craniopharyngioma is with an
MRI or a CT scan of the Pituitary region, performed with and without
"contrast enhancing" Gadolinium.
Surgery is the preferential initial treatment for a
Craniopharyngioma. The goal of surgery is to completely remove
the tumor, while improving or at least preserving Pituitary, visual
and Brain function.
Depending upon the location of the tumor, several approaches may
be utilized.
A Skull Base Tumor Craniotomy approach
(See Figures 1-3) is generally required for optimal
exposure and tumor removal if the tumor is
predominantly above the Pituitary Fossa (Suprasellar).
A Minimally Invasive Microendoscopic (or Microsurgical) Transsphenoidal technique
can be used in a minority of patients in whom the tumor
is relatively small (less than 3 cm) and located primarily
within the Sella Turcica (the Pituitary Fossa).
Radiation treatment frequently offers some degree
of tumor control and prolonged survival in those patients
where the tumor cannot be completely removed. Stereotactic
Radiation is the preferred method of Radiation since, it more
safely, delivers a higher radiation dose to the tumor although
conventional (external beam) radiation therapy can be effective in
controlling growth of Craniopharyngiomas as well.
Craniopharyngiomas have a tendency to recur,
particularly if there has not been complete surgical removal.
Long term follow up is required with repeat MRI's
or CT scans. These are usually obtained once a year. The
treatment team usually recommends the frequency and the length of
time for follow up depending on the particular circumstances of each
patient.
Endocrinological follow up is equally important, particularly
for those patients who were treated with Radiation Therapy, since
hormone deficiencies can develop many years after this
treatment.
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This page last edited on 2/19
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