Penile median raphe cysts: A multicenter retrospective clinicopathological and immunohistochemical study

To investigate the clinical, histopathological, and immunohistochemical features of penile median raphe cysts and to further characterize their epithelial phenotypes and possible histogenesis. We performed a multicenter retrospective analysis of 45 patients with penile median raphe cysts diagnosed between January 2015 and March 2026. Clinical records, histopathological findings, and immunohistochemical profiles were reviewed. Formalin-fixed, paraffin-embedded specimens were evaluated using a panel of epithelial and lineage-associated markers. The patients had a mean age of 35.6 years (range, 10-80 years). It generally presents as a translucent, skin-colored cyst located under the foreskin or on the frenulum just below the urethral opening on the glans. Histopathologically, all cysts were centered in the dermis and showed no connection with the epidermis or urethra. Nineteen cysts (42.2%) were lined entirely by like urethral transitional epithelium, 17 (37.8%) by squamous epithelium, and 9 (20.0%) showed mixed epithelial lining. Immunohistochemically, both epithelial types expressed P63 and AR. Like urethral transitional epithelium cells expressed CK7, CK20, CK19, 34βE12, and GATA3, with focal P504S positivity and negative NKX3.1 staining. The squamous epithelium expressed CEA and EMA and was negative for 34βE12 and NKX3.1. All patients underwent surgical excision, and no recurrence was observed during the available follow-up. Penile median raphe cysts are uncommon developmental lesions with heterogeneous epithelial linings. Many lesions show a urothelial-/urethral-type immunophenotype, whereas others demonstrate squamous or mixed differentiation, supporting histogenetic heterogeneity rather than a single uniform origin. Surgical excision appears to be an effective treatment.