You are in: eMedicine Specialties > Neurology > Neuro-oncology CraniopharyngiomaArticle Last Updated: Apr 11, 2006AUTHOR AND EDITOR INFORMATIONAuthor: George C Bobustuc, MD, Neuro-Oncology, MD Anderson Cancer Center Orlando George C Bobustuc is a member of the following medical societies: American Academy of Neurology, American Medical Association, Society for Neuro-Oncology, and Texas Medical Association Coauthor(s): Morris D Groves, MD, Assistant Professor, Department of Neuro-Oncology, MD Anderson Cancer Center, University of Texas; Gregory N Fuller, MD, PhD, Professor of Pathology, Chief, Section of Neuropathology, Department of Pathology, Division of Pathology and Laboratory Medicine, University of Texas M D Anderson Cancer Center; Franco N DeMonte, MD, FRCSC, FACS, Program Director, Associate Professor, Department of Neurosurgery, MD Anderson Cancer Center, University of Texas Editors: Amy A Pruitt, MD, Program Director, Assistant Professor, Department of Neurology, University of Pennsylvania; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Jorge Kattah, MD, Head, Program Director, Professor, Department of Neurology, University of Illinois College of Medicine at Peoria; Selim R Benbadis, MD, Professor, Director of Comprehensive Epilepsy Program, Departments of Neurology and Neurosurgery, University of South Florida School of Medicine, Tampa General Hospital; Nicholas Y Lorenzo, MD, Chief Editor, eMedicine Neurology; Consulting Staff, Neurology Specialists and Consultants Author and Editor Disclosure Synonyms and related keywords: adamantinoma, craniopharyngeal duct tumor, Rathke pouch tumor, craniopharyngioma, cystic tumor, Rathke cleft, epithelial-squamous calcified cystic tumor INTRODUCTIONBackgroundCraniopharyngioma is a slow-growing, extra-axial, epithelial-squamous, calcified cystic tumor arising from remnants of the craniopharyngeal duct and/or Rathke cleft and occupying the (supra)sellar region. Two main hypotheses explain the origin of craniopharyngioma—embryogenetic and metaplastic; they complement each other and explain the craniopharyngioma spectrum. Embryogenetic theory This theory relates to development of the adenohypophysis and transformation of the remnant ectoblastic cells of the craniopharyngeal duct and the involuted Rathke pouch. Both the Rathke pouch and the infundibulum develop during the fourth week of gestation and together form the hypophysis. Both elongate and come in contact during the second month. The infundibulum is a downward invagination of diencephalon; the Rathke pouch is an upward invagination of the primitive oral cavity (ie, stomodeum). The craniopharyngeal duct is the neck of the pouch, connecting to the stomodeum, which narrows, closes, and separates the pouch from the primitive oral cavity by the end of the second month. Thus, the pouch becomes a vesicle, which flattens and surrounds the anterior and lateral surfaces of the infundibulum. Walls of this vesicle form different structures of the hypophysis. Finally, this vesicle involutes into a mere cleft and may disappear completely. Rathke cleft, together with remnants of the craniopharyngeal duct, can be the site of origin of craniopharyngiomas. Metaplastic theory This theory relates to the residual squamous epithelium (derived from stomodeum and normally part of the adenohypophysis), which may undergo metaplasia. Dual theory This theory explains the craniopharyngioma spectrum, attributing the adamantinous type (most prevalent in childhood) to embryonic remnants and the adult type (ie, squamous papillary) to metaplastic foci derived from mature cells of the anterior hypophysis (prevalence of the adult type increases with each decade of life and is almost never found in children). Other cystic lesions may originate from remnants of the stomodeum and pharyngohypophyseal duct as well, such as Rathke cleft cysts, epithelial cysts, epidermoid cysts, and dermoid cysts. PathophysiologyCraniopharyngiomas are dysontogenic tumors with benign histology and malignant behavior, as they have a tendency to invade surrounding structures and recur after what was thought to be total resection. Craniopharyngioma usually presents as a single large cyst or multiple cysts filled with a turbid, proteinaceous material of brownish-yellow color that glitters and sparkles because of a high content of floating cholesterol crystals. Because of its appearance, it has been compared to machinery oil. It most frequently arises in the pituitary stalk and projects into the hypothalamus. It extends horizontally along the path of least resistance in various directions—anteriorly into the prechiasmatic cistern and subfrontal spaces; posteriorly into the prepontine and interpeduncular cisterns, cerebellopontine angle, third ventricle, posterior fossa, and foramen magnum; and laterally toward the subtemporal spaces. It can even reach the sylvian fissure. Rare locations include extradural and extracranial—nasopharyngeal or pure posterior fossa craniopharyngiomas, or craniopharyngiomas extending down the cervical spine. Purely intraventricular craniopharyngioma is usually of the squamous-papillary (metaplastic) type; it occurs very rarely. Clinical behavior and choice of surgical approach are dictated by the primary location of the tumor and its extension pattern. Both prechiasmatic craniopharyngioma (extending into subfrontal spaces) and retrochiasmatic craniopharyngioma (expanding into the posterior fossa) may reach large sizes before being diagnosed. Vascular supply is dependent on different sources, usually all from the anterior circulation. The anterior portion of the tumor is supplied by small perforators coming off A1 (ie, anterior cerebral artery); lateral portions receive perforators from the proximal portion of the posterior communicating artery; and the intrasellar part is supplied by branches of the intracavernous meningohypophyseal arteries. Craniopharyngioma rarely is supplied with blood coming from the posterior circulation, unless the anterior blood supply for the anterior hypothalamus and floor of the third ventricle is lacking. Tumor adhesion to surrounding vascular structures represents the most common cause of incomplete tumor removal. Fusiform dilatations of large surrounding vessels have been reported after attempts at radical dissection of the tumor capsule; they injure vasa vasorum, thereby weakening the adventitia. Tumor adhesion is the result of local inflammation. Recurrences usually occur at the primary site. Ectopic and metastatic recurrences are extremely rare and have been reported after surgical removal. The two possible mechanisms of seeding are dissemination of tumor cells along the surgical paths during the procedure and migration of tumor cells through the subarachnoid space or Virchow-Robin spaces (which would explain ectopic recurrences distant from the surgical bed and within brain parenchyma). In one metastatic case, after removal of a suprasellar (adamantinomatous) craniopharyngioma, 2 peripheral lesions were identified 7 years later, adjacent to the dura and contralateral to the initial craniotomy site. They proved to be adamantinomatous tissue raising the possibility of meningeal seeding. In another reported case, an adamantinomatous craniopharyngioma recurred at different intervals, at different sites, along the operative track of the initial surgical procedure and distant, within the brain parenchyma, thus, suggesting involvement of both seeding mechanisms. MIB-1 labeling index is a measure of the proliferative activity; it is determined by using an immunohistochemical method with monoclonal antibody MIB-1 and may be useful for planning of adjuvant therapy. A recent small study found that an MIB-1 labeling index greater than 7% predicted regrowth/recurrence. Genomic and molecular biology of craniopharyngiomas Comparative genomic hybridization (CGH) studies have been reported with conflicting results. CGH sensitivity is limited to deletions of the order of several megabases, and, thus, smaller deletions or balanced alterations could be missed. Some suggest that chromosomal imbalances do not play a significant role in tumorigenesis of both papillary and adamantinomatous craniopharyngiomas. Others report a small subset of adamantinomatous craniopharyngiomas showing a significant number of genetic alterations and abnormal DNA copy number, thus suggesting a monoclonal origin driven by the activation of oncogenes located at specific chromosomal loci. Adamantinomatous craniopharyngiomas have been consistently reported to show alterations in the beta-catenin gene expression. Expression of beta-catenin correlates with some of the hallmarks ("wet" keratin, calcifications and palisading cells) of adamantinomatous craniopharyngiomas. This abnormality has not been reported in papillary craniopharyngiomas. Beta-catenin is a transcriptional activator of the Wnt signaling pathway and a component of the adherence junction. Wnt signaling pathway has been proven to play a crucial role in embryogenesis and cancer. Wnt signaling is involved in determination of cell fate, proliferation, adhesion, migration, polarity, and behavior during development and plays an intricate role in the temporal and spatial regulation of organogenesis. Wnt complex comprises 3 different pathways: canonical, noncanonical, and Wnt/Ca+2. Canonical pathway regulates cell fate determination and primary axis formation through gene transcription. Noncanonical pathway regulates cell movements through modification of the actin cytoskeleton. Wnt/Ca+2 pathway is involved in regulation of both cell movement and fate determination. Immunohistochemistry for beta-catenin in adamantinomatous craniopharyngiomas showed an abnormal cytoplasmic and nuclear accumulation. The normal membranous staining was present in both adamantinomatous and papillary craniopharyngiomas. Sequencing analysis revealed beta-catenin gene mutations in adamantinomas, while none were found in papillary craniopharyngiomas. All mutations were missense mutations involving the serine/threonine residues at GSK-3beta (glycogen synthase kinase-3beta) phosphorylation sites or an aminoacid flanking the first serine residue. These mutations are considered to lead to beta-catenin accumulation as a result of impaired proteosome degradation due to ineffective phosphorylation by a mutated GSK-3beta. Furthermore, Wnt/beta-catenin signaling pathway has been shown to prevent differentiation (of mouse embryonic stem cells) through convergence on the LIF/Jak-STAT (leukemia inhibitory factor/Janus kinase-signal transducer and activator of transcription) pathway at the level of STAT3.Interferons are known modulators of Jak/STAT pathways, thus revealing the possible molecular basis for interferons as therapeutic option in adamantinomatous craniopharyngiomas. Some craniopharyngiomas express growth hormone (IGF-1R) and sex hormone receptors (ER and PR). Hormone supplementation will obviously increase the risk of recurrence and lead to significant medical management challenges. ER and PR expression in one correlative study was linked to higher differentiation and a decreased incidence of tumor recurrence and was proposed as a tool for recurrence risk stratification. FrequencyUnited StatesData from the Central Brain Tumor Registry of the United States (CBTRUS), collected between 1990 and 1993, revealed an average of 338 cases diagnosed annually with 96 occurring in children aged 0-14 years.
InternationalIncidence is 0.5-2 per 100,000 per year.
Mortality/Morbidity
RaceHigher frequencies of all intracranial tumors have been reported from Africa, the Far East, and Japan; they are 18%, 16%, and 10.5%, respectively. SexSlight male predominance exists in all age groups (55%). Age
CLINICALHistoryCraniopharyngioma usually is a slow-growing tumor. Symptoms frequently develop insidiously and mostly become obvious only after the tumor attains a diameter of about 3 cm. Time interval between onset of symptoms and diagnosis ranges from 1-2 years.
PhysicalBoth neurologic and general examinations are indicated.
DIFFERENTIALSArteriovenous Malformations Brainstem Gliomas Cavernous Sinus Syndromes Leptomeningeal Carcinomatosis Low-Grade Astrocytoma Lyme Disease Medulloblastoma Meningioma Metastatic Disease to the Brain Migraine Headache Migraine Variants Multiple Sclerosis Neurosarcoidosis Neurosyphilis Pituitary Tumors Primary CNS Lymphoma Primitive Neuroectodermal Tumors of the Central Nervous System Pseudotumor Cerebri Sarcoidosis and Neuropathy Tolosa-Hunt Syndrome Tuberculous Meningitis
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| Drug Name | Bleomycin (Blenoxane) |
|---|---|
| Description | Group of glycopeptides extracted from Streptomyces species. Each molecule has a planar end and an amine end; different glycopeptides of the group differ in their terminal amine moieties. Planar end intercalates with DNA, while amine end facilitates oxidation of bound ferrous ions to ferric ions, thereby generating free radicals, which subsequently cleave DNA, acting specifically at purine-G-C-pyrimidine sequences. Not absorbed when given orally; peak levels reached in about 30-60 min when given IM and are only one third of levels obtained after IV administration; approximately 50% of drug absorbed systemically after intrapleural or intraperitoneal administration; systemic absorption after intracavitary administration for craniopharyngioma not negligible. Volume of distribution is 20-30 L both in intracellular and extracellular fluid. Less than 10% is bound to plasma proteins. Bleomycin has plasma half-life of less than 1 h and terminal half-life of 2-4 h, but it could be as long as 22 h in patients with renal dysfunction or those previously treated with cisplatin. About 50% eliminated in urine within 24 h. Most tissues (known exceptions—skin and lungs) contain an enzyme, bleomycin hydrolase (most active tissues are liver and kidney), which readily inactivates drug; therefore, toxicity is tissue specific, occurring in tissues lacking this enzyme. Bleomycin mostly used systemically in combination with other drugs (mostly with cisplatin and vincristine) for treatment of testicular carcinoma, Hodgkin lymphoma, and non-Hodgkin lymphoma; squamous cell carcinoma of skin, head and neck, and cervix; and malignant pleural effusions. Principal mechanisms of resistance include high levels of bleomycin hydrolase, cell mutations altering DNA sequences to prevent intercalation, poor cell accumulation of drug, and rapid plasma removal. None of these factors plays important role when bleomycin administered locally in residual cyst. Toxicity is age dependent and cumulative dose related; systemic administration mostly causes pulmonary toxicity. This consists of pneumonitis, which can progress to fatal pulmonary fibrosis. Maximum recommended total cumulative dose for systemic use is 400 U. Unit measurement based on toxicity to bacteria; 1 U equals approximately 1.7 mg. Administered systemically, does not produce significant bone marrow toxicity. Toxicity with local administration due to both systemic contamination (when anaphylactoid reactions, transient fever, nausea, and vomiting could occur) and leakage into surrounding neural tissue. Fatal outcome has been reported with leakage, due to subsequent diffuse diencephalon and brainstem edema. Contrast CT cystography is required prior to intracavitary administration to ensure cyst wall integrity; when inconclusive, MR cystography with gadopentetate dimeglumine has been advocated. |
| Adult Dose | For local administration in residual cyst, dose depends on cyst volume, and repeated administrations usually required Varying dosages, in repeated administrations to total of 40-80 mg IV/IM/SC over 7-21 d, reported |
| Pediatric Dose | Not established |
| Contraindications | Documented hypersensitivity; significant renal function impairment; compromised pulmonary function |
| Interactions | Phenothiazine may enhance cytotoxicity; cisplatin decreases elimination, thereby enhancing toxicity; radiation and hyperoxia may increase pulmonary toxicity; hydrogen peroxide and ascorbic acid inactivate bleomycin |
| Pregnancy | C - Safety for use during pregnancy has not been established. |
| Precautions | Intracavitary administration requires prior contrast CT cystography to ensure cyst wall integrity; when inconclusive, MR cystography with gadopentetate dimeglumine has been advocated |
Radiation creates free oxygen ions that damage cellular DNA. Cellular ability to repair DNA is lower for tumor cells than normal cells and subsequently, with each mitosis, a higher cumulative effect in tumor cells results in apoptosis.
| Drug Name | External fractionated radiation |
|---|---|
| Description | Offers dual advantage by (1) allotting normal cells more time for repair and (2) amplifying higher cumulative effect of DNA damage in more rapidly dividing tumor cells. Radiation, following partial resection, offers excellent long-term results (80% at 20 years). Following partial resection, results of primary irradiation are superior to those with radiation delayed until time of recurrence. Recurrence is less frequent after imaging confirmed total resection (10-30% recurrence rate), in which case radiation should be delayed. |
| Adult Dose | Target volume for craniopharyngioma is narrowly confined to tumor volume (preoperative volume plus 1.5-cm margin) and should include solid component and cyst(s); should be limited to postoperative residual tumor in case of partial resection of large (multi) cystic craniopharyngioma, with special attention to cover cyst wall; high-energy photons are used with 2-3 stationary fields or classic coronal arc configuration Radiotherapy target dose should be 54-56 Gy over 30 sessions (over 6 wk; Monday-Friday weekly schedule), at 1.8-2 Gy/session (ie, per day) Dose <54 Gy has been associated with high recurrence rate (about 50%) while doses of 54 Gy or more associated with recurrence rate of only 15% Dose >60 Gy associated with marked increase in radiologic-induced endocrine, neurologic, and vascular complications |
| Pediatric Dose | Not established |
| Contraindications | Imaging confirmed total resection (10-30% recurrence rate) |
| Interactions | None reported |
| Pregnancy | B - Usually safe but benefits must outweigh the risks. |
| Precautions | Fetal exposure is <0.1 Gy (0.04-0.09% of tumor dose) at usual doses (50-68 Gy) used for brain irradiation; this confers increased (but acceptable) risk of leukemia in children, with no deleterious effects to fetus after fourth week of gestation Radiotherapy should be avoided completely in children <3-4 y Complications of radiotherapy include intellectual decline, radiation-induced necrosis, optic neuropathy, pituitary-hypothalamic damage, secondary malignant brain tumors; vascular abnormalities that occasionally lead to vasospasm; self-limiting, mostly asymptomatic, hemorrhages; less commonly, proximal irradiation of carotid arteries leads to development of Moyamoya disease |
| Drug Name | Brachytherapy/radioisotopes |
|---|---|
| Description | Recommended for solitary cystic craniopharyngiomas and consists of stereotactic aspiration of cystic content, followed by instillation of beta-emitting isotope (eg, phosphorus 32, rhenium 186, gold 198, yttrium 90). Brachytherapy is attractive because about 60% of craniopharyngiomas occur as single large cysts; early refilling is the rule, requiring intermittent aspiration either by stereotactic puncture or Ommaya reservoir. Stereotactic radiation has been used for further treatment of residual solid tumor after brachytherapy. |
| Adult Dose | Target radiation dose 200-250 Gy, aimed at inner surface of cyst wall, which is far higher than dose that can be administered safely with external beam radiation Maximum range of beta particles from phosphorous 32 in soft tissue is approximately 8 mm; more than half the dose absorbed by first 1.5 mm of tissue, which allows ablation of secretory cells within cyst wall without significant irradiation of surrounding brain tissue Brachytherapy offers both (1) advantage of high reduction in dose to normal surrounding tissues (eg, optic chiasma, hypothalamus) and (2) an option for patients who received prior external beam radiation; brachytherapy usually results in stabilization or reduction of cyst in >90% of cases |
| Pediatric Dose | Not established |
| Contraindications | Imaging confirmed total resection (10-30% recurrence rate) |
| Interactions | Not established |
| Pregnancy | C - Safety for use during pregnancy has not been established. |
| Precautions | Acute inflammatory reactions reported following brachytherapy (some authors have advocated routine use of steroids) |
| Drug Name | Stereotactic radiation |
|---|---|
| Description | Has been used primarily as first-line for treatment of growing or symptomatic, solid, small (sized) size craniopharyngioma (<25-30 mm in diameter). Stabilization or reduction of cystic cavity after radiosurgery achieved in more than 60% of patients. |
| Adult Dose | High-dose volume should be limited to well-circumscribed tumor; safety margin of at least 3-5 mm from optic nerve recommended |
| Pediatric Dose | Not established |
| Contraindications | Imaging confirmed total resection (10-30% recurrence rate) |
| Interactions | None reported |
| Pregnancy | B - Usually safe but benefits must outweigh the risks. |
| Precautions | Major complications include visual impairment; >30% of patients experience severe visual deterioration; <10% of patients show rapid visual loss Fetal exposure is <0.1 Gy (0.04-0.09% of tumor dose) at usual doses (50-68 Gy) used for brain irradiation, which confers increased but acceptable risk of leukemia in children; no deleterious effects to fetus after fourth week of gestation reported |
| Media file 1: The adamantinomatous craniopharyngioma is a histologically complex epithelial lesion with several very distinctive morphologic features. Each of these features is shown under higher power in Images 2-5 (hematoxylin-eosin, x40). | |
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| Media file 2: Adamantinomatous craniopharyngiomas. Peripheral palisading of the epithelium is a pronounced feature (hematoxylin-eosin, x100). | |
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| Media file 3: Adamantinomatous craniopharyngiomas. Frequently, the inner epithelium beneath the superficial palisade undergoes hydropic vacuolization and is referred to as the stellate reticulum (hematoxylin-eosin, x100). | |
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| Media file 4: Adamantinomatous craniopharyngiomas. Another distinctive feature of the adamantinomatous variant is scattered nodules of keratin. These nodules are referred to as "wet" keratin because of the plump appearance of the keratinocytes; this is in contrast to the flat, flaky keratin seen in epidermoid and dermoid cysts (hematoxylin-eosin, x100). | |
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| Media file 5: Adamantinomatous craniopharyngiomas. Nodules of "wet" keratin frequently calcify; in aggregate, this calcification often can be detected on CT scans, and is a recognized radiologic feature of craniopharyngiomas (hematoxylin-eosin, x100). | |
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| Media file 6: Papillary craniopharyngioma. In contrast to the adamantinomatous variant, papillary craniopharyngiomas do not show complex heterogeneous architecture (compare with Image 1) but rather are composed of simple squamous epithelium and fibrovascular islands of connective tissue (hematoxylin-eosin, x40). | |
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| Media file 7: Papillary craniopharyngiomas. Under high power, only simple squamous epithelium is seen in a papillary craniopharyngioma. The distinctive peripheral nuclear palisading, internal stellate reticulum, and nodules of "wet" keratin, which typify the adamantinomatous variant, are not seen in the papillary variant (hematoxylin-eosin, x100). | |
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| Media file 8: Rosenthal fibers in neuropils surrounding a craniopharyngioma. The brain parenchyma that surrounds both variants of craniopharyngioma is typically gliotic and often shows profuse numbers of eosinophilic Rosenthal fibers. The latter structures are composed of densely compacted bundles of glial filaments and typically are seen in astrocytic cell processes of neuropils that have been subjected to chronic compression from slowly expanding mass lesions. Rosenthal fibers are a characteristic feature of juvenile pilocytic astrocytomas (JPAs), which also may arise in the suprasellar/third ventricular region. Hence, a biopsy that samples only the surrounding neuropil of a craniopharyngioma may yield an erroneous diagnosis of JPA if the pathologist is unaware of the close association of craniopharyngioma with Rosenthal fiber formation (hematoxylin-eosin, x100). | |
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Article Last Updated: Apr 11, 2006