title: Fever of unknown origin (FUO) attributable to indolent lymphoproliferative disorder due to a plasmacytoma expressing immunoglobulin A.
abstract: BACKGROUND
  The most common categories causing fevers of unknown origin (FUOs) include infective rheumatic/inflammatory disorders and malignancies. Among neoplastic causes of FUOs, lymphomas, hepatomas, renal hypo-nephromas, and hepatomas are the most common. Other malignancies rarely present with FUOs (eg, multiple myeloma).
  
  
  METHODS
  We describe a 58-year-old man who presented with an FUO accompanied by night sweats, weight loss, and a groin mass. A biopsy of the groin mass (ie, his lymph node) was negative for infectious diseases, rheumatic or inflammatory diseases, and malignancies. Histochemical and immunological studies of the lymph node showed it to contain a plasmacytoma expressing immunoglobulin A (IgA). An immunohistochemical study of the plasma-cell infiltrate demonstrated strong CD138 staining. A bone marrow biopsy was negative for multiple myeloma.
  
  
  CONCLUSIONS
  We believe this is the first reported rare case of an indolent, lymphoproliferative disorder attributable to an IgA-secreting plasmacytoma presenting as an FUO.
authors.affiliation: Infectious Disease Division, Department of Pathology, Winthrop-University Hospital, Mineola, New York 11501, USA. bacunha@winthrop.org
authors.forename: Burke A
authors.initials: BA
authors.lastname: Cunha
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Petelin
authors.forename: George K
authors.initials: GK
authors.lastname: Turi
authors.forename: Attilio
authors.initials: A
authors.lastname: Oraji
mesh_terms: D005335:Fever of Unknown Origin / Q000209:etiology*; D006801:Humans; D007070:Immunoglobulin A / Q000378:metabolism; D007150:Immunohistochemistry; D008232:Lymphoproliferative Disorders / Q000150:complications* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D010954:Plasmacytoma / Q000150:complications* / Q000378:metabolism; D053668:Syndecan-1 / Q000378:metabolism
chemical_list: D007070:Immunoglobulin A; D053668:Syndecan-1