Micropenis is defined as a penile length less than 2.5 SD below the mean value for a given age (eg, <2.5 cm at term). Nowadays, it should be also diagnosed in utero by sonography. The incidence of micropenis has been reported as 1.5/10.000 male infants in Usa, 5/1.442 in France and 18/2710 in Brazil, suggesting geographical differences or different assessment. Micropenis represents a clinical sign, that may be part of various clinical conditions, such as hypogonadotropic hypogonadism, multiple pituitary hormone deficiencies, hypergonadotropic hypogonadism, defects in testosterone synthesis or action, and genetic or chromosomal syndromes. Iatrogenic causes (endocrine disrupters) may be involved. In some boys, the cause cannot be identified. Thus, accurate clinical and laboratory investigations are mandatory. Measurement with a ruler and comparison with available reference data permits the diagnosis. Ultrasound assessment of penis length may be an option mainly in perinatal period to obtain more accurate evaluation. Management should be performed by experienced multidisciplinary team to reach a definite diagnosis, to give an appropriate counseling and to optimize the care. Assessment of hormonal parameters of reproductive axis during the mini-puberty period and the availability of new genetic technologies may permit early etiology individuation and more rationale treatment planning. Irrespective of the underlying cause, a short course of testosterone may be tried in boys with micropenis to assess the response to androgens. Topical dihydrotestosterone gel is effective in young boys with 5alpha-reductase 2 deficiency. Infants with hypogonadotropic hypogonadism should be managed by recombinant human gonadotropins; growth hormone deficiency must be managed by appropriate hormonal therapy. Good self-body image and satisfactory sexual intercourses from adolescence onward are goals of treatment. Psychological counseling also for parents is advisable.
19 - 21 Sep 2019
European Society for Paediatric Endocrinology