Novel histopathologic findings in abdominoscrotal hydrocele: Clues to pathogenesis.
PURPOSE: To evaluate whether underlying histological alterations in hydrocele sac wall can provide an explanation of difference in abdominoscrotal hydrocele (ASH) and communicating hydrocele (CH) behavior. The aim of this study is to assess the immunohistopathologic characteristics of CH and ASH sac walls in pediatric patients. METHODS: In a retrospective case-control study, patients diagnosed with ASH or CH underwent surgical management at a tertiary pediatric center. Samples of ASH or CH wall sac were obtained for histopathologic evaluations, especially for contractile units and fibromuscular components. These assessments comprised Hematoxylin and eosin (H&E) and immunohistochemical (IHC) staining for smooth muscle actin (SMA), Myogenin and Caldesmon (H-CALD) to identify and quantify the presence of cells with striated or smooth muscle origins. All patient's imaging, clinical and demographic data were evaluated. All statistical analysis performed using SPSS software and p-value of <0.05 considered as the level of significance. RESULTS: Among 38 patients in our case-control study, 14 (36.84%) patients referred with bilateral hydrocele. The intra-operative observation of all ASH cases indicated no patent processus vaginalis. The IHC evaluations of ASH and CH specimens demonstrated that there is a significantly higher expression of SMA (median 5.73% versus 0.56%, P-Value <0.001), H-CALD (median 9.28% versus 0.18%, P-Value <0.001) in comparison to those of CH. CONCLUSION: The higher expression of smooth muscle and myofibroblast origins in the ASH wall suggests the potential of consistent contractility, which likely affects the secretion-reabsorption imbalance. Performing histologic studies can enhance our understanding of ASH pathogenesis and clinical characteristics.