title: Association between intracranial plasmacytoma and multiple myeloma: clinicopathological outcome study.
abstract: OBJECTIVE
  Intracranial plasmacytomas are rare lesions that can arise from the calvarium, dura, or cranial base and exhibit a benign course unless associated with myeloma. Attention has recently been focused on the role of the cell adhesion molecules CD56 and CD31 in the pathogenesis of myeloma. No such information is available for intracranial plasmacytomas and myeloma-associated lesions.
  
  
  METHODS
  We investigated the relationship between CD56 and CD31 expression, intracranial location, and progression to myeloma for a series of nine intracranial plasmacytomas (three dural, one calvarial, and five cranial base lesions). These parameters were also correlated with proliferation indices, as assessed by MIB-1 immunostaining of the histological sections. A single pathologist (AO) performed immunohistochemical analyses and reviewed all slides.
  
  
  RESULTS
  Intracranial plasmacytomas presented more commonly in female patients (89%). The three dural lesions were CD56- and CD31-negative and exhibited MIB-1 staining of less than 10%; no patient developed myeloma or recurrence. Of the five cranial base lesions, three were CD56-positive, none was CD31-positive, and two exhibited MIB-1 labeling of more than 45%, with plasmablastic morphological features. Compared with other intracranial plasmacytomas, five of five patients with cranial base lesions developed bone marrow biopsy-proven myeloma (P < 0.05) within 8 months. The calvarial lesion was CD56- and CD31-positive, and the patient developed myeloma soon after diagnosis. Both of the two highly proliferative plasmablastic lesions recurred, one after gross total resection without radiotherapy and the other after a biopsy and 2000-cGy radiotherapy.
  
  
  CONCLUSIONS
  Among intracranial plasmacytomas, cranial base location was the strongest predictor of the development of multiple myeloma. Expression of the cell adhesion molecules CD31 and CD56 was not predictive of outcome. Extramedullary dural-based lesions were CD56-negative and were not associated with myeloma. A high proliferation index and plasmablastic morphological features were predictive of a short time to recurrence and aggressive behavior. We recommend 4050- to 5040-cGy fractionated radiotherapy for all intracranial plasma cell neoplasms and gross total resection for non-cranial base lesions.
authors.affiliation: Department of Neurosurgery, Weill Medical College of Cornell University, New York Presbyterian Hospital, 525 East 68th Street, New York, NY 10021, USA. tschwartz1@nyc.rr.com
authors.forename: T H
authors.initials: TH
authors.lastname: Schwartz
authors.forename: R
authors.initials: R
authors.lastname: Rhiew
authors.forename: S R
authors.initials: SR
authors.lastname: Isaacson
authors.forename: A
authors.initials: A
authors.lastname: Orazi
authors.forename: J N
authors.initials: JN
authors.lastname: Bruce
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000473:pathology*; D019002:CD56 Antigen / Q000032:analysis; D004388:Dura Mater / Q000473:pathology; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000473:pathology*; D010954:Plasmacytoma / Q000473:pathology*; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000032:analysis; D011379:Prognosis; D019292:Skull Base Neoplasms / Q000473:pathology; D012888:Skull Neoplasms / Q000473:pathology
chemical_list: D019002:CD56 Antigen; D019408:Platelet Endothelial Cell Adhesion Molecule-1