PLASMACYTOID VARIANT OF UROTHELIAL CARCINOMA OF THE URINARY BLADDER: HISTOPATHOLOGIC RECOGNITION OF A RARE, AGGRESSIVE VARIANT

Abstract

Background: Plasmacytoid variant of urothelial carcinoma(PUC) is a rare and aggressive subtype of urothelial carcinoma characterized by discohesive tumor cells having plasmacytoid morphology. It is frequently associated with advanced -stage disease and poor prognosis due to its infiltrative growth pattern. This entity may pose diagnostic challenges, particularly in limited biopsy specimens where it can mimic plamsa cell neoplasms and other poorly differentiated malignancies. Case Report: We report a case of a 71-year-old woman who presented with hematuria. Imaging revealed bilateral mild hydroureteronephrosis with suspected vesicoureteric junction obstruction. Transurethral resection of bladder tumor (TURBT) was performed. Histopathological examination revealed a high grade malignant neoplasm composed of discohesive malignant cells with eosinophilic cytoplasm and  eccentric nuclei  showing plasmacytoid morphology with invasion into the muscularis propria. Immunohistochemistry showed strong membranous CD138 positivity with co expression of GATA3 and CK7 in tumor cells, supporting urothelial differentiation. Based on the morphologic and IHC findings, a diagnosis of Plasmacytoid variant of urothelial carcinoma was established. Conclusion: PUC is an uncommon but highly aggressive variant of urothelial carcinoma that often presents at an advanced stage. Recognition of the characteristic histopathologic features and appropriate use of IHC are essential to establish accurate diagnosis and facilitate timely clinical management.