title: Extramedullary laryngeal plasmacytoma in a dog.
abstract: METHODS
  An 8-year-old, female, spayed Border Collie presented with a 3-week history of coughing, choking and haemoptysis.
  
  
  RESULTS
  Inspiratory stridor was evident on clinical examination. Cervical radiographs revealed a round soft-tissue mass on the dorsal aspect of the epiglottis. A laryngeal mass was evident on examination under anaesthesia, and an incisional biopsy was obtained. Histopathology revealed a dense proliferation of neoplastic round cells morphologically consistent with plasma cell origin. Immunohistochemisty results were negative for CD3 (T cell marker) and positive for CD79a (B cell marker), resulting in a diagnosis of extramedullary plasmacytoma. The patient was treated with melphalan and prednisolone; clinical signs resolved within 1 week and the mass was no longer evident on laryngoscopy after 1 month of treatment. After 6 months of chemotherapy, the laryngeal mass recurred and euthanasia was requested. There was no evidence of systemic spread on post-mortem examination.
  
  
  METHODS
  Solitary extramedullary plasmacytoma of the canine larynx.
  
  
  CONCLUSIONS
  Respiratory extramedullary plasmacytomas are extremely rare with only one laryngeal and two tracheal cases previously reported. This is the first published report of a laryngeal plasmacytoma that recurred despite combination chemotherapy with melphalan and prednisolone.
authors.affiliation: Institute of Veterinary, Animal and Biochemical Sciences, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand. awitham@unimelb.edu.au
authors.forename: A I
authors.initials: AI
authors.lastname: Witham
authors.forename: A F
authors.initials: AF
authors.lastname: French
authors.forename: K E
authors.initials: KE
authors.lastname: Hill
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000627:therapeutic use; D004283:Dog Diseases / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery; D004285:Dogs; D005260:Female; D007822:Laryngeal Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000601:surgery / Q000662:veterinary*; D010954:Plasmacytoma / Q000188:drug therapy / Q000473:pathology / Q000601:surgery / Q000662:veterinary*
chemical_list: D000970:Antineoplastic Agents