A 12-year-old boy is evaluated for chronic headaches and visual changes. The headaches have progressively worsened over the past year and are associated with nausea. The patient's parents are especially concerned as his symptoms have been interfering with his coursework in middle school. An intracranial calcified mass is detected on brain imaging. The mass is surgically removed and on gross inspection shows cystic spaces filled with thick, brownish-yellow fluid that is rich in cholesterol. This mass is most likely derived from cells responsible for forming which of the following structures?

Question

A 12-year-old boy is evaluated for chronic headaches and visual changes.  The headaches have progressively worsened over the past year and are associated with nausea.  The patient's parents are especially concerned as his symptoms have been interfering with his coursework in middle school.  An intracranial calcified mass is detected on brain imaging.  The mass is surgically removed and on gross inspection shows cystic spaces filled with thick, brownish-yellow fluid that is rich in cholesterol.  This mass is most likely derived from cells responsible for forming which of the following structures?

Quizplus · Accepted Answer

11ec160b_39d9_5b10_9249_a14a77cbf8b6_MD0001_00 This patient most likely has an adamantinomatous craniopharyngioma. These are rare, slow-growing (benign) intracranial tumors found in children and typically located in the suprasellar region. On macroscopic examination, they are cystic or partially cystic with solid areas. The cysts are usually filled with a brownish-yellow, viscous fluid that resembles machine oil due to the presence of protein and cholesterol crystals. Dystrophic calcification of the cysts is highly characteristic and may be detected on neuroimaging. On light microscopy, the cysts are lined by cords/nests of stratified squamous epithelium with peripheral palisading and internal areas of lamellar "wet" keratin. Craniopharyngiomas are derived from remnants of Rathke's pouch, which is an evagination of the surface ectoderm that lines the fetal oral cavity. This protrusion of the roof of the mouth forms the anterior pituitary gland (adenohypophysis). The posterior lobe of the pituitary (neurohypophysis) forms from an outpouching of the diencephalon (infundibulum) and is derived from neuroectoderm. (Choices B, C, D, and E) The cerebellum, pineal gland, and retina are derived from neuroectoderm. Epithelial cells of the choroid plexus are also derived from neuroectoderm, whereas the mesenchyme (eg, blood vessels, connective tissue) is derived from mesoderm. Educational objective: Craniopharyngiomas are suprasellar tumors found in children and composed of calcified cysts containing cholesterol crystals. They arise from remnants of Rathke's pouch, an embryonic precursor of the anterior pituitary. __________ References: Craniopharyngioma: a pathologic, clinical, and surgical review. (http://www.ncbi.nlm.nih.gov/pubmed/21584897)

A 12-Year-Old Boy Is Evaluated for Chronic Headaches and Visual