A Rare Case of Granular Cell Tumor of the Urethra Provoking Urinary Retention

Abstract

A 44-year-old woman was referred to urologist for urinary retention due to a urethral mass. Magnetic resonance imaging (MRI) showed a round mass that surrounded the urethra completely. The regional lymph nodes were normal and no other lesions were identified. Biopsy was performed revealing a tumor that was composed of large polygonal cells with eosinophilic and periodic acid-Schiff (PAS) - positive granular cytoplasm, indistinct cell margins and small round central nuclei. Immunohistochemical staining for S100 protein, vimentin, calretinin and inhibin Α was positive, indicating a granular cell tumor. Excision of the tumor including the urethra and an umbilical catheterized stoma using Mitrofanoff principle was performed.