|Patient: 14 year 4 month old female|
|History: 14 yo female eating disorder clinic patient with subtle blunted affect and abnormal EEG findings.|
| Findings: |
2cm Sellar mass with increased T1 signal, iso to increased mixed signal on T2 and Flair signal, and no appreciable contrast enhancement. Mass is displacing the optic chiasm and MCAs superiorly.
| Discussion: |
Craniopharyngioma represents 3-5% of all primary brain tumors. The bimodal age distribution includes a peak incidence at 5-10 years of age (making it the most common suprasellar tumor in children) and later in the 6th decade of life.
Craniopharyngiomas frequently present clinically with signs and symptoms of hypothalamic pituitary hypofunction, visual disturbances, and signs of increased intracranial pressure.
The tumor arises from squamous epithelial nests of Rathke’s pouch.
Histologically, there are two types:
Adamantinomatous- these are the type found most commonly in pediatric patients. They have both cystic and solid elements. The cystic component is made of cholesterol crystals, and resembles “machine-oil.” The solid component is clumps of squamous and columnar tissues containing keratin.
Papillary or squamous- these are of the adult variety. They have a greater solid element with significant squamous differentiation.
On CT a craniopharyngioma will appear as a suprasellar, mixed solid and cystic mass. The vast majority will have extrasellar location at presentation; intrasellar tumor alone represents only 6% of craniopharyngiomas. Nodular or curvilinear calcification is very common. Enhancement may be vary. MRI signal intensity is also extremely variable. TI hyperintensity has been shown to coorelate with protein, fat and/or the presence of hemorrhage (methemoglobin).
Differential diagnosis includes but is not limited to:
Pituitary adenoma- these typically benign tumors arise from the pituitary gland. They are classified as micro (<10mm diameter) or macroadenomas (>10mm). Microadenomas usually secrete ATCH or prolactin, while macroadenomas secrete GH or are non-secreting. MRI is the most accurate imaging modality. T1-weighted with and without gadolinium contrast studies are very helpful. The tumor remains hypointense while the remainder of the gland enhances homogeneously. This allows characterization of precise size and location.Germinoma- Intracranial germ cell tumours are relatively uncommon, comprising approximately 0.5-11% of all intracranial tumours. They most commonly arise in the midline, involving the pineal region in 50%, suprasellar region in 40% and both these sites in about 6% of cases. The remaining cases occur in non-midline structures which include basal ganglia, thalamus, cerebral hemisphere and structures in the posterior fossa. Suprasellar germ cell tumours present with the classic triad of visual disturbances, diabetes inspidus and varying degree of hypopituitarism in about 20% of patients. They have a significant male predilection (male:female=2.24:1), irrespective of the tumor type, and the majority of patients are diagnosed between 10-21 years of age. Germinomas are most common germ cell tumor in the suprasellar region. Neuroimaging shows that germinomas are usually solid. The solid parts are isointense with grey matter on both T1- and T2-weighted images. Cystic components can be seen. The solid components of germinomas either enhance homogeneously or heterogeneously.
Chiasmatic astrocytoma- the cells of this tumor arise from the glia of the optic chiasm. The tumor may be sporadic but is much more commonly part of Neurofibromatosis type I syndrome CT will show a suprasellar, well-defined, lobular mass of variable density. MR imaging is more specific, with hypointense T1 imaging and hyperintense T2 imaging at the optic chiasm. Retrochiasmatic extension may be identified on T2 images.
Dermoid cyst- a rare ectodermal inclusion cyst with cheesy or greasy contents. Similar to epidermoid cysts, they are lined by squamous epithelium, but dermoid cysts have a more developed underlying stroma and may have dermal appendages (hair follicles & adnexae). On CT it will appear as a well circumscribed, rounded mass whose contents have negative attenuation values and may demonstrate hair. MRI will show signal hyperintensity on T1, and variability on T2.
Rathke cleft cyst-Rathke's cleft cyst is a non neoplastic lesion remnant of the Rathke's poutch. Symptomatic cysts must be surgically treated. Because cyst fluid of Rathke's cleft cysts shows variable intensities on MR images, the specific diagnosis is often difficult when based on MR signal intensity values alone. The presence of an intracystic nodule with characteristic signal intensities on MR images may be indicative of the diagnosis of Rathke's cleft cyst.
Transphenoidal surgery has been the treatment of choice despite considerable risk of injury to adjacent structures including the pituitary and the difficulty of excising the multicystic and adherent tumors. Additionally the tumor may represent one mentioned in the differential diagnosis rather than being a craniopharyngioma. Recent literature highlights the value of transcranial , sometimes transcallosal resection in the pediatric population since it is associated with a lower risk of damage to the pituitary stalk and subsequent hypopituitarism.
The experience at Children’s Memorial Hospital shows that total resection provided the best outcome. However, recurrence rates and surgical complications sometimes remain high following radical tumor resection. Radiotherapy was effective for recurrent tumors and should be considered being the primary treatment for recurrences or difficult tumors, which are not amenable to total resections.
The acute neurologic, cognitive, and endocrine effects of surgery often affect long-term function and quality of life. The St. Jude Children's
| References: |
Contributed by: Jennifer Lee,Creighton Medical Student M4, Creighton University, Omaha, NE References:
Jennifer Lee,Creighton Medical Student M4, Creighton University, Omaha, NEPatrick A. Harty,M.D.,Radiology Resident, Creighton University,Omaha,NE
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| Additional Details:|
Case Number: 628928Last Updated: 08-20-2006 The reader is fully responsible for confirming the accuracy of this content.
The reader is fully responsible for confirming the accuracy of this content.