Are androstenedione, dihydrotestosterone, thyroid-stimulating hormone, insulin-like growth factor I, and insulin-like growth factor binding protein 3 necessary for isolated micropenis healthy boys' evaluation without any phenotypic abnormalities? A cross-sectional study.

The study aimed to familiarise primary care physicians and specialists with the minimum hormonal diagnostic tests necessary to assay isolated micropenis in healthy children without any phenotypic abnormality. Children aged 6-15 years (mean 11.6 ± 1.68) were assessed from May 2010 to September 2021 (N = 247). Multiple regression analysis showed correlations between stretched penile length (SPL) and hormonal assays as follows: follicle-stimulating hormone (FSH): r = 0.097, p = 0.035; luteinizing hormone (LH): r = 0.139, p = 0.012, thyroid-stimulating hormone (TSH): r = -0.001, p = 0.321; testosterone (T): r = 0.118, p = 0.004; dihydrotestosterone (DHT): r = 0.002, p = 0.243; androstenedione (Δ4And): r = -0.004, p = 0.502; insulin-like growth factor I (IGF-I): r = -0.003, p = 0.062; and IFG-binding protein 3 (IGF-BP 3 ): r = 0.052, p = 0.051. The most hormonal disorder was testosterone deficiency. TSH, Δ4And, and DHT were normal in all boys. SPL was significantly correlated with FSH, LH, and T, but there was no significant correlation between SPL and TSH, DHT, Δ4And, IGF-I, and IGF-BP 3 . Whenever the isolated micropenis is seen without other anomalies, it is sufficient to assay testosterone, FSH, and LH in the first step.