Micropenis/Micropenis

Micropenis refers to a normally structured penis, which is abnormally small, with a stretched length of less than 2.5 standard deviations (SD) below the mean of age or stage of sexual development. Patients with true micropenis usually have a 46,XY karyotype, associated to normally located male gonads, without any sign of other penile malformations. Penile length is measured from the point where the penis meets the pubic bone to the distal tip of the glans on maximal stretch, compressing any fat over suprapubic area. Differential diagnosis include buried penis (inability to adequately expose the penis, due to a severe phymosis associated to a decreased length of penile skin, which retain the shaft inside the preputial cavity), and obesity with excess fat pad over supra pubic area. The causes of congenital or true micropenis can be divided into three major groups: hypogonadotropic hypogonadism (pituitary/ hypothalamic failure), hypergonadotropic hypogonadism (primary testicular failure) and idiopathic (associated with a functional hypothalamus-pituitary-testicular axis). Clinical treatment is based on testosterone therapy. Surgical treatment options are used after failed penile enlargement with testosterone therapy and include penile elongation, suprapubic fat pad aspiration and eventually neophaloplasty. Keywords: Penis/abnormalities; Penis/pathology; Penis/ physiopathology; Urology; Pediatrics; Endocrinology. Micropenis refere-se a um penis normalmente formado, anormalmente pequeno, com um comprimento inferior a 2,5 desvios-padrao (DP) abaixo da media da idade ou do estagio de desenvolvimento sexual. Pacientes com micropenis verdadeiro geralmente apresentam cariotipo 46, XY, associado a gonadas masculinas normalmente localizadas, sem qualquer sinal de outras malformacoes penianas. O comprimento do penis e medido a partir do ponto onde o penis encontra o osso pubico ate a ponta distal da glande no alongamento maximo, comprimindo qualquer gordura sobre a area suprapubica. O diagnostico diferencial inclui buried penis--penis embutido (incapacidade de expor adequadamente o penis, devido a uma severa estomia associada a diminuicao do comprimento da pele do penis, que retem o eixo dentro da cavidade prepucial) e obesidade com excesso de gordura na regiao supra pubica. As causas do micropenis congenito ou verdadeiro podem ser divididas em tres grandes grupos: hipogonadismo hipogonadotrofico (falencia hipofisaria / hipotalamica), hipogonadismo hipergonadotrofico (