Clinicopathological study of 34 cases of clear cell adenocarcinoma of the urinary tract and diagnostic value of SOX 17 in its differential diagnosis
Clear cell adenocarcinoma (CCA) of the urinary tract is a rare tumor with a female predominance. The morphological features and immunoprofile of urinary CCA, CCA of the gynecologic tract (Gyn CCA), and nephrogenic adenoma (NA) can show extensive overlap, and the differential diagnosis can be challenging especially in small biopsies. SOX17 is a newly identified sensitive and specific immunomarker for endometrial and ovarian carcinomas including Gyn CCA. However, its expression in urinary CCA and NA has not been studied. We studied clinical and pathological features of 34 cases of urinary CCA, the largest cohort in the literature to date. We analyzed the expression pattern of SOX17 in a cohort of 34 urinary CCA, 24 Gyn CCA, and 18 NA. Interestingly, 29 % (10/34) of urinary CCA showed high SOX17 expression, while all the NA cases (18/18) showed negative-low expression. In female, 51 % of urinary CCA cases (15/29) show negative-low expression of SOX17, whereas all Gyn CCA (24/24) showed high SOX17 positivity. Our study showed a unique expression pattern of SOX17 in urinary CCA and NA. These results suggest that SOX17 is a useful marker in distinguishing CCA from NA or urinary CCA from Gyn CCA. Moreover, our study suggests different pathogenic pathways for the histogenesis of urinary CCA.
