Systematization of ambiguous genitalia

Abstract

ABSTRACT. Sex assignment in newborns depends on the anatomy of the external genitalia, despite this stage being the final in embryogenesis. According to the current view, the genital tubercle is the embryonic precursor of penis and clitoris. It originates from mesenchymal tissue, but mesenchymal cells are arranged across the embryonal body and do not have specific androgen receptors. The nature of the signal that initiates early derivation of the indifferent genital tubercle is unknown at present. The aims of this article are to improve surgical management of intersex disorders and investigate the development of the genital tubercle. Clinical examination of 114 females with various forms of DSD revealed ambiguous (bisexual) external genitalia in 73 patients, and 51 of them underwent feminizing surgery. Intersexuality (ambiguity) in 46,XY patients results from disruptors in the pathways of sex steroid hormones or receptors; in 46,XX females arises from excessive levels of androgens. Systematization of intersex disorders distinguishes the karyotype, gonadal morphology, and genital anatomy to provide a differential diagnosis and guide appropriate surgical management. Modified feminizing clitoroplasty with preservation of the dorsal and ventral neurovascular bundles to retain erogenous sensitivity was performed in females with severe virilization (Prader degree III-V). The outgrowth of the genital tubercle and the fusion of the urethral fold proceed in an ordered fashion; but in some cases of ambiguity, there was discordance due to different pathways. Speculation about the derivation of the genital tubercle have discussed with a literature review. The genital tubercle derives from the following 3 layers: the ectodermal glans of the tubercle, the mesodermal corpora cavernosa and the endodermal urogenital groove. According to the new hypothesis, during the indifferent stages, the 5 sacral somites have to recede from their segmentation and disintegrate: the sclerotomes form the pelvic bones, the fused myotomes follow with their genuine neurotomes and the angiotomes join to the corpora cavernosa of the genital tubercle. Sexual differentiation of external genitalia is final in gender embryogenesis, but surprisingly derivation of the indifferent genital tubercle from 5 somites occurs before gonadal and internal organs development.

Midline raphe scroti artery flap for penile shaft reconstruction

“…During embryonal development, the external genitalia in both sexes originate from the genital tubercles and swellings. Under the influence of male or female hormones, genital swellings differentiate into the scrotum (dihydrotestosterone) or labia majora (estrogen) [25] . In females, the process continues with separation of the genital swellings that surround the vaginal vestibulum; in the male embryo, both genital swellings fuse in the midline to become the scrotal sac [25] .…”

“…Under the influence of male or female hormones, genital swellings differentiate into the scrotum (dihydrotestosterone) or labia majora (estrogen) [25] . In females, the process continues with separation of the genital swellings that surround the vaginal vestibulum; in the male embryo, both genital swellings fuse in the midline to become the scrotal sac [25] . The scrotal septum depicts the fusion line of both genital swellings, and it is not surprising that it consists of two thin membranes with identical anatomical structure.…”

Phenotypic Heterogeneity in Tumor Progression, and Its Possible Role in the Onset of Cancer

“…The chromosomes primarily characterize the former while the latter is a multi-parametric process involving genetic, regulatory or hormonal aspects of gonadal development. The outcomes of any abnormality in the development of external or internal genital structures are clinically classified as disorders of sex development (DSD) (Makiyan, 2016). There are multiple non-genetic factors involved in DSD, unlike in case of a chromosomal abnormality.…”

Sonographic measure techniques of fetal penile length

“…During the initial stages of organogenesis, 3 basic structures are formed: bipotential gonads, genital passages, and indistinct external genitalia including the phallus and genital folds. Stimulation provided by the placental human chorionic gonadotropin causes the Leydig cells to produce testosterone as early as the 7th week of gestation [ 4 ]. The influence of this androgen results in sexual differentiation, due to which the phallus elongates to become a penis; genital folds fuse to form the scrotum, and the bipotential gonads form the testicles [ 5 ].…”