Plasmacytoid urothelial carcinoma

Abstract

Objective: Plasmacytoid urothelial carcinoma (PUC) is a rare histological and aggressive variant of urothelial carcinoma that is often diagnosed at an advanced stage. We report a case of a 58-year-old male with hematuria and lower abdominal pain. After thorough clinical examination, he underwent a radical cystoprostatectomy. Material and Methods: The cystoprostatectomy specimen showed gray-brown exophytic tumor measuring 10x8x5 cm on the front bladder wall. The tumor infiltrated the bladder wall, extended into the perivesical fat, and grossly infiltrated the prostate. Standard tissue samples were embedded in paraffin blocks and hematoxylin-eosin and immunohistochemical stainings were made. Results: Histological analysis showed infiltrative high-grade invasive urothelial carcinoma, mainly composed of dyscohesive polygonal to round tumor cells, with hyperchromatic, eccentrically located nuclei with eosinophylic cytoplasm, with plasmacytoid appearance. The microscopic analyses confirmed the extension of the tumor into perivesical fat and the prostate, as well as into the mucous and submucous layer of the left ureter. Bilateral iliac and obturatory lymph nodes were free of tumor. Immunohistochemical staining showed positive signal for CK-7, CK-20, CK AE1/AE3, EMA, CD-138 and negative signal for LCA, S-100, kappa, lambda, CD79-a. Conclusions: The diagnosis of this rare histological variant can be difficult because of its morphological resemblance with plasmacytoma, although the PUC cells are lacking prominent perinuclear clearing and there is no multinucleation. Our case did not have such a diagnostic dilemma, since alongside the PUC, there was a typical invasive urothelial carcinoma.