title: Cytopathology of extramedullary plasmacytoma of the bladder: a case report.
abstract: BACKGROUND
  Plasmacytoma of the bladder is an extremely rare tumor, with all information concerning this neoplasm derived from case reports. It can be a major diagnostic pitfall on both histology and urine cytology.
  
  
  METHODS
  A 95-year-old woman presented with gross hematuria and a large bladder mass detected by ultrasound. The case was initially misdiagnosed as a high grade urothelial carcinoma. Since the urine cytology did not show the classical cytologic features of urothelial carcinoma, the histologic sections were reviewed and immunohistochemical staining performed. The final diagnosis was plasmacytoma of the bladder. Subsequently the patient underwent a skeletal survey and bone scan, which did not reveal any lesion suspicious for multiple myeloma. The patient was scheduled for radiotherapy.
  
  
  CONCLUSIONS
  In this case of bladder plasmacytoma, urine cytology provided a clue to the diagnosis. Urine cytology can be a diagnostic tool to help make this diagnosis in the case of poorly differentiated bladder neoplasm, especially in a patient with a known history of multiple myeloma.
authors.affiliation: Department of Pathology, Ottawa Hospital, Civic Campus, University of Ottawa, Ottawa, Ontario, Canada. ghadeer200@hotmail.com
authors.forename: Ghadeer A
authors.initials: GA
authors.lastname: Mokhtar
authors.forename: Hossein
authors.initials: H
authors.lastname: Yazdi
authors.forename: Kien T
authors.initials: KT
authors.lastname: Mai
mesh_terms: D000369:Aged, 80 and over; D002277:Carcinoma / Q000473:pathology / Q000652:urine; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000032:analysis; D007150:Immunohistochemistry; D008562:Membrane Glycoproteins / Q000032:analysis; D018396:Mucin-1 / Q000032:analysis; D010954:Plasmacytoma / Q000473:pathology* / Q000652:urine; D011509:Proteoglycans / Q000032:analysis; D053667:Syndecans; D001749:Urinary Bladder Neoplasms / Q000473:pathology* / Q000652:urine; D014556:Urine / Q000166:cytology*; D019459:Urothelium / Q000473:pathology
chemical_list: D007145:Immunoglobulin kappa-Chains; D008562:Membrane Glycoproteins; D018396:Mucin-1; D011509:Proteoglycans; D053667:Syndecans