(92) Perineal groove, no need to remove!

Background: Perineal groove is a rare anogenital malformation divided into a complete and an incomplete type, where the complete perineal groove extends from the vaginal fourchette to the anus and the incomplete type extends either from the vaginal fourchette to midperineum or from the anus to midperineum. The perineal groove is a fairly unknown entity frequently leading to misdiagnosis, e.g. perineal trauma, diaper dermatitis, fissure ani, infection or sexual abuse. Correct diagnosis is key because incorrect diagnosis can lead to unnecessary medical treatments or surgical interventions.

Case: Case 1. A 16-month-old female patient referred by her pediatrician with suspicion of perineal skin tag and related perianal fistula. She was born after a term pregnancy without complication and no other associated anomalies were noted. Her medical history showed constipation ever since birth with solid stools and sporadic anal blood loss. On inspection a moist groove from midperineum to anus was present, with at the anterior part of the perineum a different aspect of the skin in the midline suggesting spontaneous recovery of a larger groove. After a 7 months period of expective management reevaluation showed almost complete reduction of the lesion.
Case 2. A 27-month-old female patient was recently referred by the dermatologist after a first episode of yeast infection of a perineal defect. Her mother had already noticed an abnormal appearance of the perineum shortly after birth, but the midwife and the maternity aid considered it a normal finding. No specific complaint arose in the first two years, so no reevaluation took place. The dermatologist referred as the diagnosis of a perineal groove was considered but uncertain because of the location. On inspection a mucosal aspect over the anterior half of the perineum in the midline. No clear dimple or groove was recognized. Expectant management was advised and follow-up appointment was scheduled.

Comments: A perineal groove is a congenital anomaly of the perineum. It is not associated with other urogenital malformations, but occasionally with anorectal anomalies. The lesion is self-resolving, by the age of two. Surgery is only recommended in case of recurrent inflammation or infections. Knowledge of the perineal groove as a transient abnormal form of perineum will avoid misdiagnosis, prevents unnecessary procedures and will help to provide reassurance and support to caregivers.