Laboratory Studies
The basic laboratory evaluation for females or males suspected of having luteinizing hormone (LH) deficiency includes serum levels of thyroid-stimulating hormone (TSH), prolactin (PRL), LH, follicle-stimulating hormone (FSH), and estradiol. Low or normal LH and FSH levels in the presence of low estradiol suggest a hypothalamic problem. A pituitary problem is most commonly associated with elevated PRL levels.
Imaging Studies
When hypothalamic or pituitary dysfunction is suspected, the most important imaging study is magnetic resonance imaging (MRI) of the head to determine the presence of a tumor or other abnormality.
MRI of pituitary macroadenoma.
Other Tests
Olfactory testing
When Kallmann syndrome is suspected, olfactory testing can be performed. Screening tests can be performed using vanilla or aromatic oils (eg, wintergreen, cinnamon). Quantitative tests have been developed using either scratch-and-sniff panels or serial dilutions of odorants such as dimethyl sulfide or acetic acid. Perhaps the most widely used clinical olfactory test is the University of Pennsylvania Smell Identification Test (UPSIT) that uses scratch-and-sniff panels. [19] Caustic substances such as rubbing alcohol should not be used, as these are recognized by chemoreceptors, not the affected olfactory receptors.
Screening for eating disorders
Patients suspected of have an eating disorders can be screened for by asking the British SCOFF questions [20] :
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Do you ever make yourself SICK when you feel uncomfortably full?
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Do you worry you have lost CONTROL over how much you eat?
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Have you lost more than 14 pounds (ONE stone's worth of weight) within the last 3 months?
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Do you believe you are FAT when others say you are too thin?
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Would you say that FOOD dominates your life?
Procedures
Transsphenoidal resection is used to remove pituitary macroadenomas (>1 cm in diameter) that remain symptomatic or increase in size despite medical treatment.
Histologic Findings
Pituitary adenomas are rarely malignant. The most common benign adenomas are prolactinomas (70%). Approximately 25% of adenomas do not secrete a functional hormone (null cell tumors) but may secrete free alpha subunits. The remainder secrete TSH, GH, ACTH, and in rare cases, LH and FSH.
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MRI of pituitary macroadenoma.
