A novel histologic finding in male patients with bladder outlet obstruction: a possible etiopathogenesis of Marion's disease?

Purpose: George Marion first described primary bladder neck obstruction in 1933. Even today, the etiopathogenesis of this condition is unknown. The objective of this study is to associate a novel histologic finding with Marion's disease to contribute to its etiopathogenesis, and to seek the reason why the lower urinary tract symptoms of some patients was not relieved after pharmacological treatment.
Methods: The retrospective study was carried out with patients who underwent transurethral resection of the prostate from 2009 to 2019. Patients with histological diagnosis did not present hyperplastic nodules, and the presence of skeletal muscle fibers were included in the study. The frequency of cases with presence of skeletal muscle fibers was assessed as well as the area occupied by these fibers in each resected fragment. As a control group, fragments of bladder neck of surgical specimens from 50 radical prostatectomies were analyzed.
Results: In 14 patients with skeletal muscle fibers in the resected fragments the extent of each positive fragment was < 25%, > 25-50%, > 50-75%, and > 75% in 28.6%, 28.6%, 21.4%, and 21.4% fragments, respectively. In the control group, 20% (10/50) of the patients had skeletal muscle fibers and, in all cases, they occupied < 25%.
Conclusion: In these 14 cases, the presence of skeletal muscle fibers is frequent and predominant in TURP fragments, which stands in striking contrast to the control group. We consider that presence of skeletal muscle fibers may be related to Marion's disease, thus contributing to explain its etiopathogenesis and the unsuccessful alpha-blocker treatment in these patients.
(© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.)