Dermatology: Practical and Conceptual Research Letter | Dermatol Pract Concept. 2025;15(3):5303 1 Congenital Perineal Groove in Males: A Comprehensive Review of a Rare Anomaly Julia Nowowiejska1, Vincenzo Piccolo2, Dirk Van Gysel3,4, Ramon Grimalt5, Andrea Bassi6, Mario Cutrone7 1 Department of Dermatology and Venereology, Medical University of Bialystok, Poland 2 Dermatology Unit, University of Campania, Naples, Italy 3 Interdisciplinary Unit of Pediatric Dermatology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium 4 Department of Pediatrics, O.L. Vrouw Hospital Aalst, Aalst, Belgium 5 Universitat Internacional de Catalunya, Barcelona, Spain 6 Division of Dermatology, Azienda Toscana Nord Ovest, Lucca, Italy 7 Ambulatorio di Dermatologia Pediatrica, Centro di Medicina Mestre Venezia, Italy Key words: Perineal groove, Congenital anomaly, Pediatric dermatology Citation: Nowowiejska J, Piccolo V, Van Gysel D, Grimalt R, Bassi A, Cutrone M. Congenital Perineal Groove in Males: A Comprehensive Review of a Rare Anomaly. Dermatol Pract Concept. 2025;15(3):5303. DOI: https://doi.org/10.5826/dpc.1503a5303 Accepted: January 7, 2025; Published: July 2025 Copyright: ©2025 Nowowiejska et al. This is an open-access article distributed under the terms of the Creative Commons Attribution- NonCommercial License (BY-NC-4.0), https://creativecommons.org/licenses/by-nc/4.0/, which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original authors and source are credited. Funding: None. Competing Interests: None. Authorship: All authors have contributed significantly to this publication. Corresponding Author: Assist. Prof. Julia Nowowiejska, MD, PhD, Department of Dermatology and Venereology, Medical University of Bialystok, Poland. ORCID 0000-0002-6870-1167. E-mail: julia.nowowiejska@umb.edu.pl Introduction Perineal groove (PG) is a rare congenital anomaly marked by an epithelialized furrow extending from the scrotum or posterior aspect of the male genitalia toward the anus [1]. While it is more commonly documented in females [2], cases in males, though rarer, do occur. This condition is benign and usually asymptomatic [2], though its unique appearance can understandably cause concern. Case Presentation A 3-day-old male newborn, delivered at term after an un- complicated pregnancy, presented with a normal perinatal course. Physical examination revealed typical male genitalia, testicles in place. However, a slightly moist, red fissure was noted along the median perineal raphe, extending from the base of the scrotum toward the anus (Figure 1A). The lesion was non-tender, and urination was normal, with no signs of infection on urinalysis. Ultrasound imaging confirmed that the lesion was superficial, with no abnormalities detected in the urinary tract or other structures. Conclusion In male patients, the PG appears as a non-keratinized, moist furrow along the perineum, lacking hair follicles and sweat glands and resembling mucosa rather than typical perineal 2 Research Letter | Dermatol Pract Concept. 2025;15(3):5303 skin [3,4]. This groove is often discovered during the new- born’s initial physical examination [3,5]. The groove typically extends from the scrotal base to- ward the anus, while surrounding skin is normally devel- oped, without functional abnormalities in the genital or anorectal regions. The PG is generally an isolated anom- aly, with no associated congenital malformation in most cases [2,3]. The exact cause of the PG remains unclear, though it is believed to arise from incomplete fusion of the urogenital folds during fetal development. Failure of this fusion results in the epithelialized furrow characteristic of the PG [5]. PG is typically considered a cosmetic anomaly without significant functional implications. However, in rare cases, it may be associated with other urogenital or anorectal ab- normalities [5], underscoring the importance of a thorough clinical evaluation. Diagnosis of a PG is generally based on its characteristic appearance during the newborn examination [2,5]. Its moist, epithelialized nature distinguishes it from other conditions, such as fistulas or incomplete anal openings. A detailed phys- ical examination, often including palpation of surrounding structures, is usually sufficient to confirm the diagnosis [2]. The possible differential diagnoses are presented in Table 1 and Figure 1, B-D. In most cases, imaging studies or further diagnostic pro- cedures are unnecessary unless there is concern about associ- ated anomalies [5]. If there is suspicion of anal malformation or other urogenital anomalies, ultrasound or MRI may be used to rule out any underlying conditions [6]. PG in males rarely requires surgical intervention, as it tends to epithelialize and heal spontaneously within the first few months of life [5]. Conservative management, such as keeping the area clean and applying protective barriers, is typically sufficient [2]. The long-term prognosis for males with PG is excellent [5]. This anomaly does not impact urinary or bowel func- tion, and the groove generally closes on its own as the child grows. There are no known long-term complications associ- ated with untreated PG [3]. PG is a rare benign congenital anomaly in males. While its appearance may initially cause concern, it is generally as- ymptomatic and resolves spontaneously. Early recognition of the condition is important to prevent unnecessary proce- dures [1]. Further studies into the embryological origins of the PG could provide insight into its etiology and any poten- tial risk factors. For now, clinicians should be aware of this condition. Informed Consent: The patient’s parents in this manuscript have given written informed consent to the publication of his case details. References 1. Samuk I, Amerstorfer EE, Fanjul M, et al. Perineal Groove: An Anorectal Malformation Network, Consortium Study. J Pediatr. 2020;222:207-212. DOI:10.1016/j.jpeds.2020.03.026 Table 1. Possible Differential Diagnoses of Perineal Groove. Differential Diagnosis Differentiating Features Perineal hemangioma Vascular, size augmentation in weeks Perineal staphylococcal infection New blisters, fast response to antibiotic therapy, acquired, not congenital Perineal streptococcal infection Acquired, not congenital; painful, perianal area also involved Figure 1. (A) Perineal groove in the described patient and possible differential diagnoses: (B) perineal hemangioma, (C) perineal staphylo- coccal infection, and (D) perineal streptococcal infection. Research Letter | Dermatol Pract Concept. 2025;15(3):5303 3 2. Servidio AG, Baldo F, Barbi E. Perineal groove: A rare con- genital malformation.  Pediatr Neonatol. 2022;63(2):192-193. DOI:10.1016/j.pedneo.2021.09.002. 3. Wang K, Pang W, Chen W, Zhang D, Wu D, Chen Y. Charac- teristics and treatment of congenital perineal groove in male patients. Front Pediatr. 2023;11:1103867. Published 2023 Feb 2. DOI:10.3389/fped.2023.1103867. 4. Harsono M, Pourcyrous M. Perineal Groove: A Rare Congen- ital Midline Defect of Perineum.  AJP Rep. 2016;6(1):e30-e32. DOI:10.1055/s-0035-1566311. 5. Moreno Alfonso JC, Velayos M, Andrés Moreno A, et al. Perineal groove: an old, little known entity. Surco perineal: un viejo poco conocido. Cir Pediatr. 2022;35(3):146-148. Published 2022 Jul 1. DOI:10.54847/cp.2022.03.19 6. Boutsikou T, Mougiou V, Sokou R, et al. Four Cases of Perineal Groove-Experience of a Greek Maternity Hospital.  Medicina (Kaunas). 2019;55(8):488. Published 2019 Aug 15. DOI:10.3390 /medicina55080488.