title: Reaction patterns of TRAP and DBA.44 in hairy cell leukemia, hairy cell variant, and nodal and extranodal marginal zone B-cell lymphomas.
abstract: BACKGROUND
  The differential diagnosis of hairy cell leukemia (HCL) includes HC variant (HC-V) and marginal zone lymphoma (MZL). There is a high sensitivity of combined DBA.44/TRAP-positivity (+) in confirming HCL. A previous study of mucosa-associated lymphoid tissue lymphoma showed DBA.44+ in 10%, TRAP+ in 29%, and DBA.44+/TRAP+ in 5%.
  
  
  OBJECTIVE
  We now study nodal MZL (NMZL) and HC-V.
  
  
  METHODS
  Two HCL, 2 HC-V, 3 MZL of bone marrow (BM), 2 MZL versus B-cell lymphoma, not otherwise specified (BCL, NOS) of BM, and 4 NMZL and 5 extranodal MZL (EMZL) were stained with DBA.44 and TRAP and reviewed for staining pattern/intensity.
  
  
  RESULTS
  DBA.44 intensely stained all cells in 2/2 HCL, 1/2 HC-V, and 1 EMZL; intensely stained >20% of neoplastic cells (NCs) in 7 MZLs (1 BM, 3 NMZL, and 3 EMZL); and was negative/stained <10% of NCs in 1/2 HC-V, the remaining MZLs (2 BM, 1 NMZL, and 1 EMZL), and 2/2 MZL versus BCL, NOS-BM. TRAP intensely stained all cells in 2/2 HCL, the DBA.44+ HC-V, and 1 MZL versus BCL, NOS-BM; intensely stained >20% of NCs in 1 MZL versus BCL, NOS-BM, 1 MZL-BM, and 1 EMZL; and was negative in the remainder (1 HC-V, 2 MZL-BM, 1 MZL vs. BCL, NOS-BM, the 4 NMZL, 3 EMZL) in which it was able to be performed. There was combined DBA.44+/TRAP+ in 2/2 HCL, 1/2 HCV, 1/3 MZL-BM, and 1/5 EMZL. Only 1 case (MZL vs. BCL, NOS-BM) was TRAP+/DBA.44-.
  
  
  CONCLUSIONS
  Although combined intense, diffuse TRAP+/DBA.44+ is highly sensitive for HCL, it is not entirely specific, and may be observed in HC-V and EMZL, further supporting a histogenetic relationship between these entities.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599-7525, USA. cdunphy@unch.unc.edu
authors.forename: Cherie H
authors.initials: CH
authors.lastname: Dunphy
mesh_terms: D000135:Acid Phosphatase / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000032:analysis*; D003937:Diagnosis, Differential; D006801:Humans; D007527:Isoenzymes / Q000032:analysis*; D007943:Leukemia, Hairy Cell / Q000175:diagnosis* / Q000378:metabolism; D016393:Lymphoma, B-Cell / Q000737:chemistry / Q000175:diagnosis*; D012269:Ribosomal Proteins / Q000032:analysis*; D000071681:Tartrate-Resistant Acid Phosphatase
chemical_list: D014408:Biomarkers, Tumor; D007527:Isoenzymes; D012269:Ribosomal Proteins; C040343:ribosomal protein S19; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase