Plasmacytoma with involvement of the urinary bladder. Report of a case diagnosed by urine cytology.

Background: Plasmacytoma of the bladder is a rare but important entity. We report a case of plasmacytoma of the bladder that was diagnosed by urinary cytology.

Methods: A 71-year-old male with a history of multiple myeloma presented in renal failure. Renal ultrasound revealed right-sided, moderate hydronephrosis with a 4 x 4-cm, posterolateral, obstructing mass. Magnetic resonance imaging demonstrated a bladder mass involving the bladder base, right lateral wall and dome with extension into the perivesical tissues on the right. The mass showed a moderate degree of enhancement following intravenous gadolinium administration. Urine cytology was performed to evaluate for bladder carcinoma or other malignancies besides plasmacytoma. The specimen was signed out as multiple myeloma of the bladder. Cystoscopy and biopsy were subsequently performed on the bladder mass. The diagnosis of plasmocytoma was made, confirming the urine cytology diagnosis.

Conclusions: Urinary cytology can be a diagnostic tool for plasmocytoma involving the bladder.