Plasmacytoid urothelial carcinoma; A series of two cases and the approach to diagnosis

Plasmacytoid urothelial carcinoma (PUC) is a rare and aggressive variant of urothelial carcinoma. PUC can occur in any part of the urinary tract, but the upper ureteric origin is extremely rare, with only two cases reported to date. The diagnosis of this specific variant of urothelial carcinoma has prognostic implications and necessitates close oncological follow up after surgical resection. We report two cases of urothelial carcinoma with plasmacytoid differentiation in two different locations of the urinary tract. The first case was of a 59-year-old man who was investigated for right loin pain. He was found to have a lesion in the right upper ureter with imaging evidence of right side hydronephrosis and upper hydroureter. The lesion was sampled with ureteroscopic washings and cup biopsy and later underwent a right nephroureterectomy following the diagnosis of urothelial carcinoma. The second case was of a 77-year-old man who was investigated for painless macroscopic haematuria. Imaging revealed a lesion in the anterior wall of the  bladder. Transurethral resection of bladder tumour was performed.  Histology and immunocytochemistry of both lesions were compatible with PUC.  These cases highlight the importance of identifying and reporting this rare variant of invasive urothelial carcinoma as it has a poor outcome compared to usual urothelial carcinoma.