title: Differentiating benign from malignant bone marrow B-cell lymphoid aggregates: a statistical analysis of distinguishing features.
abstract: BACKGROUND
  Lymphoid aggregates are seen in a minority of bone marrow biopsy specimens, and when present, their neoplastic nature is often apparent by morphologic evaluation. However, the distinction between benign and malignant aggregates can be a diagnostic challenge when there are multiple aggregates with no documented history of lymphoma.
  
  
  OBJECTIVE
  To aid in the distinction between benign and malignant B-cell lymphoid aggregates.
  
  
  METHODS
  Previously, we described specific distribution patterns for B and T lymphocytes within bone marrow aggregates. To statistically analyze the significance of these patterns as well as previously reported criteria, we examined 128 bone marrow specimens with benign aggregates and 78 specimens with documented malignant B-cell aggregates and calculated specific odds ratios (ORs) and 95% confidence intervals (CIs) to aid in differentiating between benign and malignant B-cell aggregates.
  
  
  RESULTS
  Aggregates with infiltrative edges (OR, 80.54; 95% CI, 31.76-204.21), a B-cell pattern (OR, 30.08; 95% CI, 13.28-68.10), paratrabecular location (OR, 10.17; 95% CI, 3.96-26.12), size greater than 600 μm (OR, 6.83: 95% CI, 3.61-12.93), or cytologic atypia correlated with malignancy.
  
  
  CONCLUSIONS
  When taken collectively, the presence of more than 2 of these characteristic features was strongly predictive of malignancy.
authors.affiliation: From the Departments of Pathology and Laboratory Medicine, University of California Irvine School of Medicine, Orange (Drs Johnston, Reisian, Bhansali, Zhao, and Rezk); the University of Southern California Keck School of Medicine, Los Angeles (Dr Brynes); and Pathology and Laboratory Medicine, University of California San Francisco Medical Center, San Francisco (Dr Naemi).
authors.forename: Abbey
authors.initials: A
authors.lastname: Johnston
authors.forename: Russell K
authors.initials: RK
authors.lastname: Brynes
authors.forename: Kaveh
authors.initials: K
authors.lastname: Naemi
authors.forename: Niloufar
authors.initials: N
authors.lastname: Reisian
authors.forename: Deepty
authors.initials: D
authors.lastname: Bhansali
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Zhao
authors.forename: Sherif A
authors.initials: SA
authors.lastname: Rezk
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001402:B-Lymphocytes / Q000378:metabolism / Q000473:pathology*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001706:Biopsy; D001853:Bone Marrow / Q000473:pathology*; D001854:Bone Marrow Cells / Q000378:metabolism / Q000473:pathology*; D002648:Child; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D008221:Lymphoid Tissue / Q000473:pathology*; D016393:Lymphoma, B-Cell / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D013601:T-Lymphocytes / Q000378:metabolism / Q000473:pathology; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor