Laboratory Services

Testosterone, Total by Mass Spectrometry, Serum

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Updated Test Information:

Test Description
Testosterone, Total by Mass Spectrometry, Serum
Synonym(s)

Androgens; Testosterone, Total Serum; Testosterone, Total Only, Serum; Testosterone; Testosterone Group

Test ID
TTST
General Information

Useful for:



  • Evaluation of men with symptoms or signs of possible hypogonadism, such as loss of libido, erectile dysfunction, gynecomastia, osteoporosis, or infertility

  • Evaluation of boys with delayed or precocious puberty

  • Monitoring testosterone replacement therapy

  • Monitoring antiandrogen therapy (eg, used in prostate cancer, precocious puberty, treatment of idiopathic hirsutism, male-to-female transgender disorders, etc.)

  • Evaluation of women with hirsutism, virilization, and oligoamenorrhea

  • Evaluation of women with symptoms or signs of possible testosterone deficiency

  • Evaluation of infants with ambiguous genitalia or virilization

  • Diagnosis of androgen-secreting tumors

  • See Steroid Pathways

Specimen Type

Serum

Specimen Requirements

Red Top

Required Information

Patient's age and sex are required

Stability

  • Refrigerated (preferred): 14 days

  • Frozen: 60 days

Unacceptable Specimen Conditions

  • Gross hemolysis

  • Gross lipemia

  • Gross icterus

  • Serum Gel (SST)

Limitations

  • Early-morning testosterone levels in young male individuals are on average 50% higher than p.m. levels. Reference ranges were established using specimens collected in the morning

  • Testosterone levels can fluctuate substantially between different days, and sometimes even more frequently. Assessment of androgen status should be based on more than a single measurement

  • The low end of the normal reference range in pre-pubertal subjects is not yet established due to sensitivity limitations of current assay methodologies.

Methodology

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Estimated TAT

2-3 days

Testing Schedule

Monday-Saturday

Retention

14 days

CPT Code(s)

84403

Additional Information
Minimum Sample Volume

0.215 mL

Reference Range
Age (years) Males (ng/dL) Females (ng/dL)
< 0.5 75 - 400 20 - 80
0.5 - 9 <7 - 20 <7 - 20
10 - 11 <7 - 130 <7 - 44
12 - 13 <7 - 800 <7 - 75
14 <7 - 1200
15 - 16 100 - 1200
17 - 18 300 - 1200 20 - 75
≥ 19 240 - 950 8 - 60
Tanner Stages*    
Stage I (prepubertal) <7-20 <7 - 20
Stage II 8-66 <7 - 47
Stage III 26-800 17 - 75
Stage IV 85-1,200 20 - 75
Stage V (young adult) 300-950 12 - 60

*Puberty onset (transition from Tanner stage I to Tanner stage II) occurs for boys at a median age of 11.5 (+/-2) years and for girls at a median age of 10.5 (+/-2) years. There is evidence that it may occur up to 1 year earlier in obese girls and in African American girls. For boys, there is no definite proven relationship between puberty onset and body weight or ethnic origin. Progression through Tanner stages is variable. Tanner stage V (young adult) should be reached by age 18.

Performing Lab

Mayo

LOINC Code(s)

2986-8