H/O headaches, nausea and blurred vision.
There is evidence of a lobulated extra-axial mass lesion in the suprasellar cistern. The lesion is predominantly hyperintense on the T1W images and heterogeneously hyperintense on the T2W and FLAIR images. The optic chiasm, proximal optic nerves and the pituitary stalk cannot be identified separately from this lesion. However, the pituitary gland is well identified. The patient had refused contrast administration.
Craniopharyngiomas are epithelially derived neoplasms that usually occur in the suprasellar cistern. Occasionally they occur in the sella or in the third ventricle. They constitute approximately 3% of all intracranial tumors and show no sex predilection. Craniopharyngiomas are hormonally inactive lesions. 50% of these lesions occur in childhood or adolescence, with a peak incidence between 5 and 10 years of age. A second smaller peak is seen in the sixth decade. Patients may present with headaches and/or visual disturbances.
There are two different types of craniopharyngiomas: adamantinomatous and papillary (squamous) types.
Adamantinomatous Craniopharyngioma:
These are usually see in in the suprasellar region and present in the first two decades of life. They may present with headaches, nausea, vomiting and/or visual disturbances. They may also present with pituitary hypofunction due to compression upon the pituitary gland, pituitary stalk or hypothalamus. Occasionally they rupture into the subarachnoid space (chemical meningitis). Very rarely they are found in the sella, posterior fossa, pineal region, third ventricle or in the nasal cavity.
Pathology:
They usually have both solid and cystic components, but may be predominantly cystic. Typically the cyst exhibits a dark brown "machine-oil" appearance that contains cholesterol crystals. Calcification is common. They contain cords of columnar or squamous epithelium with keratin formation. Extensive fibrosis and signs of inflammation are common, more so when they are recurrent, so that they adhere to adjacent structures.. They may invade the adjacent brain and invoke a fairly dense gliotic response.
MRI:
The lesions usually exhibit a heterogeneous appearance but the cyst is fairly well defined. It may be hyperintense on both T1W and T2W images. The lesions may encase nearby cerebral vasculature. The solid portion is usually calcified and may be completely calcified. On contrast the solid portion usually enhances.
Papillary Craniopharyngioma:
These lesions are usually found in adults. They are solid, not calcified and commonly occur in the third ventricle. They are fairly well encapsulated and recur less often than the adamantinomatous type.
Pathology:
These lesions reveal extensive squamous differentiation.
MRI:
These are solid lesions and are often located within the third ventricle. They
have a nonspecific signal intensity pattern and enhance after contrast
administration.
Differential Diagnosis:
For sellar and suprasellar lesions:
Large Pituitary Adenoma
Craniopharyngioma
Rathke Cleft Cyst
Meningioma
Germinoma and Teratoma
Epidermoid and Dermoid
Glioma - Chiasmatic and Hypothalamic
Arachnoid Cyst
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