Congenital Perineal Groove Defect in Monozygotic Twin Infants: A Literature Review

Abstract

Perineal groove is a rare benign congenital anomaly with lesion that resembles perforation of mid-perineum or perineal raphe area. Most reported cases of congenital perineal groove presented as an isolated defect in term or early-term singleton female infants. Thus far, there is no reported case of this anomaly in monozygotic twins. Embryo pathogenesis of this female predominance congenital defect remains controversial. Many clinicians are unfamiliar with this congenital anomaly. This congenital defect tends to get self-resolved at around 2 year of age. Nevertheless, the exposed nonepithelized mucous membrane can carry risk of local infection or irritation with the possibility of requiring early surgical correction. The defect can be infrequently associated with other ano-urogenital malformations that required immediate surgical intervention. Most isolated cases tend to be asymptomatic and self-healed with expectant management. Surgical correction may be considered if not healed after 2 years of age. Early diagnosis at birth is important to avoid misdiagnoses at later age for trauma, dermatitis, sexual abuse, and risk of unnecessary aggressive intervention. Early parental counseling for providing good hygiene and close follow-up is important to prevent infection or inflammation. Presentation of this anomaly in both monozygotic twins may support the hypothesis of potential disruption during embryo morphogenesis stages.

Characteristics and treatment of congenital perineal groove in male patients

“…When various insults interrupt the process and cause defects in extension of the urorectal septum, it would result in a shortened perineum and anterior anus ( 10 ). The failure of genital folds fusion at midline would cause sulcus ( 1 , 3 , 8 , 10 , 11 , 16 ). Interruption of labioscrotal fold development contributes to penoscrotal transposition and bifid scrotum ( 3 , 10 ).…”

“…The failure of genital folds fusion at midline would cause sulcus ( 1 , 3 , 8 , 10 , 11 , 16 ). Interruption of labioscrotal fold development contributes to penoscrotal transposition and bifid scrotum ( 3 , 10 ). Push force from the bilateral mesenchyme promotes the midline fusion ( 14 ).…”

“…Currently, CPG can be divided into two types based on the morphology of perineum, complete and partial ( 2 , 3 , 8 ). The complete type has the sulcus extended from the posterior fourchette to the anterior edge of the anus in female patients.…”

Perineal groove: Case report

“…Perineal groove is a rare, congenital midline anomaly largely defined by its wet sulcus extending from the posterior vaginal fourchette to the anterior anus. 4 Although the embryologic cause of perineal grooves has yet to be determined, several hypotheses have been proposed. These include a defective uroanal septum, persistent open cloacal duct, and incomplete fusion of the perineal raphe or median genital folds.…”

A Rare Congenital Perineal Groove

“…When part of this merging does not take place, the raphe is replaced by the groove [ 2 ]. Even if in majority of cases the defect is presented as isolated defect, there is case report happening in monozygotic twins [ 8 ].…”