A 17-year-old male presents with 3-month history of headache, weight gain, decreased concentration, polyuria, and polydypsia. His headaches are mostly in morning and involves the frontal region. On examination he was found to have bitemporal visual field defect and no facial hair. MRI scan revealed a suprasellar paially calcified cystic lesion with displacement of optic chiasm. The most likely pathology is:

- Weight gain, DI, decreased memory, and visual field defect are consistent with a suprasellar hypothalamic lesion. - Calcified cystic lesions in this location, paicularly in adolescents, are characteristic of Craniopharyngiomas. - The rate of calcification in childhood is about 85% and in adult is about 40%. - Craniopharyngiomas are pathologically benign but due to their location and their firm attachment to critical structures surrounding them can result in severe neuro-functional impairment. - The cyst wall is lined with squamous epithelium and the fluid contains cholesterol crystals.