When should a hormone panel be ordered in a patient?

When to Order a Hormone Panel

Order a hormone panel when patients present with specific clinical conditions or symptoms that suggest endocrine dysfunction, rather than as routine screening in asymptomatic individuals.

Testosterone Testing in Men

Clear Indications for Measurement 1

Measure testosterone in all male patients with the following conditions, even without symptoms:

• Infertility 1
• Pituitary disorders 1
• Chronic corticosteroid use 1
• Symptomatic patients with signs of testosterone deficiency 1

Adjunctive Hormone Testing When Testosterone is Low 1

When initial testosterone is low, follow this algorithmic approach:

1. Measure serum LH in all patients with low testosterone 1

   • Low or low-normal LH suggests secondary (central) hypogonadism 1
   • Elevated LH suggests primary testicular failure 1

2. Measure serum prolactin if testosterone is low AND LH is low or low-normal 1

   • Repeat if elevated to confirm it's not spurious 1
   • Persistently elevated prolactin requires endocrinology referral for possible prolactinoma 1

3. Order pituitary MRI if total testosterone <150 ng/dL with low/low-normal LH, regardless of prolactin level 1

   • Non-secreting adenomas may be present 1

4. Measure estradiol only in testosterone-deficient patients presenting with breast symptoms or gynecomastia before starting therapy 1

5. Fertility evaluation for men interested in preserving fertility 1

   • Measure FSH 1
   • Elevated FSH with low testosterone indicates impaired spermatogenesis 1
   • Consider semen analysis in this setting 1

Thyroid Testing

Screening Recommendations 1

The USPSTF finds insufficient evidence to recommend routine screening for thyroid dysfunction in asymptomatic, nonpregnant adults 1. However, aggressive case-finding is appropriate in specific populations.

When to Test TSH 1

Order TSH (with or without free T4) in these clinical scenarios:

• Women planning pregnancy or already pregnant 2
• Postpartum women with depression, unusual fatigue, anxiety, or symptoms of thyroid dysfunction 2
  • Postpartum thyroiditis occurs in 6-8% of women 2
• Patients >60 years old with nonspecific symptoms 1
• Patients with menstrual disorders as part of differential diagnosis 2
  • Though thyroid abnormalities are relatively infrequent causes of menstrual irregularities 2
• Patients on immune checkpoint inhibitors 1
  • Check TSH (with option for FT4) every 4-6 weeks during routine monitoring 1
  • Check TSH and FT4 for symptomatic patients 1

Critical Testing Caveat 1

Always measure both TSH and free T4 when hypothyroidism is suspected clinically, as TSH can remain within normal range in central hypothyroidism (hypophysitis) 1. Low TSH with low FT4 indicates central hypothyroidism requiring evaluation for pituitary dysfunction 1.

Prolactin Testing

Specific Indications 1, 3

Measure prolactin in:

• Men with low testosterone AND low/low-normal LH 1
• Women with secondary amenorrhea 3
  • Hyperprolactinemia is associated with amenorrhea and may coexist with thyroid dysfunction 3

Not Recommended 4

Do not routinely order prolactin in asymptomatic women with infertility and normal menstrual cycles 4. Only 1.77% of such patients have elevated prolactin 4.

Patients on Immunotherapy

Routine Monitoring Schedule 1

For patients receiving interferon-α2b, IL-2, or ipilimumab, obtain:

• TSH, complete blood counts, liver enzymes, metabolic panels, and LDH 1
• Frequency: Weekly during induction, then monthly until stable for interferon 1; daily during IL-2 1; before each ipilimumab infusion every 3 weeks 1

Additional Hormone Testing for Suspected Hypophysitis 1

If signs of pituitary dysfunction develop on ipilimumab:

• TSH, free T4, ACTH, morning cortisol 1
• Consider co-syntropin stimulation test, LH, FSH, testosterone, and prolactin 1
• Early endocrinology referral is recommended 1

What NOT to Do

• Do not use screening questionnaires as substitutes for laboratory testosterone measurement 1
• Do not routinely screen asymptomatic adults for thyroid dysfunction 1
• Do not order comprehensive hormone panels in asymptomatic infertile women with regular cycles—only 2.48% have abnormal TSH and 1.77% have elevated prolactin 4