Urinary Bladder Transitional Cell Carcinoma with Chordoid Features-A Rare Entity

Abstract

Abstract Casestudy: Invasive urothelial carcinoma is heterogenous entity and show variant morphologic patterns, of which squamous differentiation is the most common. Other variants have been widely recognized and studied. Invasive urothelial carcinoma with chordoid features is a rare entity with only 16 reported cases to date in English literature. It has a significant morphologic overlap with other vesical and non-vesical myxoid neoplasms, including extra-skeletal myxoid chondrosarcoma and chordoma, which necessitate an extensive workup to reach an accurate diagnosis. To the best of our knowledge we report the 17th case of urothelial carcinoma with chordoid features in a 76-year-old male who underwent a cystoprostatectomy and bilateral pelvic lymph node dissection with confirmed diagnosis of high-grade invasive urothelial carcinoma on biopsy. Grossly, bladder showed a 4.2 x 3.4 x 0.6 cm firm white tumor entirely replacing the anterior wall, extending into perivesicular fat, and invading the prostate gland and seminal vesicles. Microscopically, tumor showed urothelial carcinoma in-situ transitioning into high-grade invasive carcinoma with chordoid features. The tumor characterized by round to elongated epithelial cells and eosinophilic cytoplasm arranged in a single file/complex cord-like architecture, in a prominent myxoid stromal background. No conventional high-grade spindle cell morphology was identified. Pelvic lymph nodes were positive for metastatic disease. Tumor cells were positive for GATA3, Pan-cytokeratin, 34BetaE12, and p63, while negative for AMCAR, supporting the urothelial origin of this tumor and confirming the diagnosis. Invasive urothelial carcinoma with chordoid features is a rare entity, generally present at high stage disease, that can be mistaken for other prominent myxoid stromal neoplasms and requires careful assessment. Although, it can demonstrate similar demographic, clinical and immunohistochemical staining pattern as of conventional urothelial carcinoma, special attention should be given to exclude sarcomatoid features which is an aggressive variant of urothelial carcinoma.