Evaluation of Lab Reports – Miss Tanisha Kumawat (18 yr, Female)

1. Thyroid Function Test (T3, T4, TSH) – All three values sit comfortably within the euthyroid reference range. This effectively rules out both hypothyroidism and hyperthyroidism as a cause of any presenting complaint (e.g., menstrual irregularity, hair loss, weight change, or hirsutism), which is why TFT is routinely the first screen in an androgen-excess work-up - thyroid dysfunction can independently cause menstrual irregularity and skin/hair changes that mimic hyperandrogenism.

2. Free Testosterone – 0.67 pg/mL is well below the upper limit of 4.2 pg/mL, with no biochemical evidence of hyperandrogenism. This sample was analyzed by mass spectrometry (the lab specifically flags "change in method" to LC-MS/MS), which is the gold-standard, most specific method for steroid hormone quantification - so this result can be trusted with high confidence.

3. Dihydrotestosterone (DHT) – 200.0 pg/mL falls within the premenopausal female reference range (24–368 pg/mL) and is also below the Tanner stage 5 (adult) cutoff of ≤300 pg/mL. So on paper this is normal, though it sits in the mid-to-upper portion of the normal range. One caveat: this assay was run by ELISA, not mass spectrometry. ELISA-based steroid immunoassays are known to have cross-reactivity with structurally similar steroids and are generally considered less specific/accurate than LC-MS/MS - according to endocrine literature (e.g., Tietz Textbook of Laboratory Medicine, and Harrison's Principles of Internal Medicine), DHT and other androgen levels are best confirmed with mass-spec based assays when there is diagnostic doubt, especially in women where absolute levels are low and immunoassays lose precision. Testosterone is converted to DHT by 5α-reductase, and DHT (not testosterone) is the androgen that binds most potently to the androgen receptor and mediates hirsutism/acne clinically - Harrison's Principles of Internal Medicine, 22E.

This panel (TFT + free testosterone + DHT) is the classic biochemical work-up ordered when a young woman presents with hirsutism, acne, irregular menstrual cycles, or suspected PCOS. Based purely on these three reports:

Important clinical caveat: Normal circulating androgens do not exclude PCOS. Per Rotterdam criteria, diagnosis requires 2 of 3: oligo/anovulation, clinical or biochemical hyperandrogenism, and polycystic ovarian morphology on ultrasound. If the patient has clinical hyperandrogenism (hirsutism, acne, androgenic alopecia) despite normal labs, that alone can satisfy the "hyperandrogenism" criterion (per The Harriet Lane Handbook, hyperandrogenism can be clinical OR biochemical). If PCOS or another endocrinopathy is still suspected clinically, the work-up should be extended with LH/FSH ratio, DHEA-S, pelvic ultrasound, and possibly 17-OH progesterone (to exclude late-onset congenital adrenal hyperplasia), and androgen levels ideally re-confirmed with LC-MS/MS if ELISA-based DHT is borderline.

As both reports note, clinical correlation is essential - these values should be interpreted alongside the patient's menstrual history, hirsutism score (e.g., Ferriman-Gallwey), acne pattern, and any ultrasound findings before drawing a final conclusion.