Laboratory parameters of the 1st order – obligatory laboratory tests.
- LH*
- FSH*
- Prolactin*
- Estradiol*
- Testosterone* (hypogonadism?)
- Sex hormone binding globulin* (SHBG).
- Dehydroepiandrosterone sulfate* (DHEAS)
- Thyroid parameters – TSH (thyroid-stimulating hormone) – exclusion of hyperthyroidism (hyperthyroidism); this induces the peripheral conversion of testosterone to estrogens.
- Liver parameters* – alanine aminotransferase (ALT, GPT), aspartate aminotransferase (AST, GOT), glutamate dehydrogenase (GLDH) and gamma-glutamyl transferase (gamma-GT, GGT).
- Renal parameters – urea, creatinine, possibly cystatin C or creatinine clearance – exclusion of renal insufficiency (kidney weakness).
- Tumor markers (ß-HCG* , AFP* (alpha-fetoprotein), Ca 15-3 – exclusion of a mammary or testicular tumor (the gynecomastia may be the first symptom of a testicular tumor!).
- Fine needle biopsy (removal of a tissue sample)/punch biopsy – if a carcinoma is suspected.
* Performed in pubertal gynecomastia according to the S1 guideline gynecomastia.
Laboratory parameters 2nd order – depending on the results of the history, physical examination and mandatory laboratory parameters – for differential diagnostic clarification.
- Pituitary function test – to check pituitary function (function of the pituitary gland).
- Karyogram (chromosome analysis) – for suspected Klinefelter syndrome.