Saturday, 7 November 2015

Diagnosis of a Pituitary Adenoma | AIPGMEE Preparations


Which of the following tests is most sensitive for the diagnosis of a pituitary adenoma? 

A. Serum prolactin measurement 
B. Visual field examination 
C. CT scan with contrast injection 
D. MRI with gadolinium injection

Ans. D. MRI gadolinium injection


MRI with gadolinium is the most sensitive test for the detection of microadenomas, revealing them in 1O%—20% of normal women. Oversecretion of prolactin is present in only 30%—50% of patients with pituitary adenomas. Impaired GH response to insulin- induced hypoglycemia or visual field changes would occur only in those tumors that are large enough to interfere with normal pituitary function or to compress the optic chiasm. CT scans reveal very small adenomas, but MRI with gadolinium is even more sensitive.