title: Inflammatory pseudotumour (plasma cell granuloma) arising in the maxillary sinus.
abstract: CONCLUSIONS
  Inflammatory pseudotumours in the maxillary sinus may present as malignant tumours and manifest locally aggressive features characteristic of such tumours. Despite their locally destructive features, they pursue a benign course after local excision.
  
  
  OBJECTIVE
  Inflammatory pseudotumour (plasma cell granuloma) is an uncommon non-neoplastic lesion comprising a proliferation of spindle myofibroblasts and chronic inflammatory cells. Despite its benign histopathological nature, it may exhibit aggressive behaviour that is yet to be characterized in the head and neck area.
  
  
  METHODS
  We present the cases of two adult patients with inflammatory pseudotumour arising from the maxillary sinus. Immunohistochemistry and polymerase chain reaction for immunoglobulin from tissue sections were performed to confirm the polyclonality of the infiltrating plasma cells.
  
  
  RESULTS
  CT and MRI disclosed expansive soft masses eroding surrounding soft and bony tissues. Histopathologically, the lesions were unencapsulated and composed of numerous plasma cells, histiocytes and spindle cells with minimal nuclear pleomorphism.
authors.affiliation: Department of Pathology, Hirosaki University, Zaifucho, Hirosaki, Japan.
authors.forename: Shin-Ichiro
authors.initials: S
authors.lastname: Maruya
authors.forename: Hidekachi
authors.initials: H
authors.lastname: Kurotaki
authors.forename: Toshimitsu
authors.initials: T
authors.lastname: Hashimoto
authors.forename: Shuji
authors.initials: S
authors.lastname: Ohta
authors.forename: Hideichi
authors.initials: H
authors.lastname: Shinkawa
authors.forename: Soroku
authors.initials: S
authors.lastname: Yagihashi
mesh_terms: D000328:Adult; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000032:analysis; D005260:Female; D006104:Granuloma, Plasma Cell / Q000175:diagnosis* / Q000378:metabolism / Q000628:therapy; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000378:metabolism; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging; D008297:Male; D008444:Maxillary Sinus Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000628:therapy; D014057:Tomography, X-Ray Computed
chemical_list: D007147:Immunoglobulin Light Chains; D002097:C-Reactive Protein