Perineal Groove: Is It More Common Than We Think? Clinical Characteristics of Four Cases and Review of Literature

Background: Perineal groove is a very rare congenital malformation that usually occurs in females. It has been described as a wet, un-epithelialized mucus tissue extending from the posterior vaginal fourchette to the anterior anal opening. It is generally asymptomatic and self-limited. Due to its rarity, it is often unfamiliar to clinicians, often leading to a missed diagnosis or unnecessary interventions. Methods: During the period from September 2017 to September 2020, four patients (two newborns and 2 infants) were diagnosed with perineal grooves. They were referred to the pediatric surgery clinic because of abnormal findings during their genital examinations. During the same period of time, the clinic received 12 other new patients with various forms of anorectal malformations. Results: All four patients were girls. During examinations by their respective pediatricians, an abnormality in the perineum was noted in each of the patients. The depth of the grooves varied between the four patients and extended from the anus to the vaginal fourchette. None of the patients experienced any other symptoms related to the malformation. All the cases were referred to the pediatric surgeon by their pediatricians as a diagnosed anal fissure or abnormal finding in the genitalia. In all four patients, the mothers did not take folic acid during the pregnancy. The four patients were observed, and no surgery was needed; in three of the cases, there was a complete spontaneous resolution while the fourth patient still remains under observation. Conclusions: Perineal groove is a rare malformation with a low incidence rate. It is more common in female infants and usually self resolves before the age of 2 years. The condition is diagnosed on clinical examination; however, it is easily misdiagnosed and may lead to unnecessary interventions and surgery.