A 5-Year-Old Boy Is Brought to the Office by His

question 135

Multiple Choice

A 5-year-old boy is brought to the office by his parents for evaluation of "clumsiness."  The patient's fine and gross motor development have been normal at prior visits, but he now frequently runs into doorways or corners of furniture while walking around the house.  He has also begun drinking large amounts of water and urinating "all the time."  Temperature is 37 C (98.6 F) , blood pressure is 95/65 mm Hg, and pulse is 130/min.  Physical examination shows dry mucous membranes and loss of peripheral visual fields.  Laboratory results are as follows: CT scan of the brain (exhibit) reveals an abnormality.  Which of the following is the most likely diagnosis?

• A)Craniopharyngioma
• B)Medulloblastoma
• C)Parasagittal meningioma
• D)Pituitary adenoma
• E)Rathke cleft cyst

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Definitions:

Ideal Gas Law

The principle that the state of an ideal gas is determined by its pressure, volume, and temperature, described by the equation PV=nRT.

Gaseous System

A state of matter composed of particles that have neither a defined volume nor shape, often able to expand to fill any container.

Temperature

The average kinetic energy of particles within a substance, which shows the temperature level, defining its heat or coldness.

Mass Spectroscopy

An analytical technique that measures the mass-to-charge ratio of ions to identify and quantify molecules in a sample.