title: Role of flow cytometry immunophenotyping in the diagnosis of leptomeningeal carcinomatosis.
abstract: OBJECTIVE
  To explore the contribution of flow cytometry immunophenotyping (FCI) in detecting leptomeningeal disease in patients with solid tumors.
  
  
  METHODS
  Cerebrospinal fluid (CSF) samples from 78 patients who received a diagnosis of epithelial-cell solid tumors and had clinical data suggestive of leptomeningeal carcinomatosis (LC) were studied. A novel FCI protocol was used to identify cells expressing the epithelial cell antigen EpCAM and their DNA content. Accompanying inflammatory cells were also described. FCI results (positive or negative for malignancy) were compared with those from CSF cytology and with the diagnosis established by the clinicians: patients with LC (n = 49), without LC (n = 26), and undetermined (n = 3).
  
  
  RESULTS
  FCI described a wide range of EpCAM-positive cells with a hyperdiploid DNA content in the CSF of patients with LC. Compared with cytology, FCI showed higher sensitivity (75.5 vs 65.3) and negative predictive value (67.6 vs 60.5), and similar specificity (96.1 vs 100) and positive predictive value (97.4 vs 100). Concordance between cytology and FCI was high (Kp = 0.83), although misdiagnosis of LC did not show differences between evaluating the CSF with 1 or 2 techniques (P = .06). Receiver-operator characteristic curve analyses showed that lymphocytes and monocytes had a different distribution between patients with and without LC.
  
  
  CONCLUSIONS
  FCI seems to be a promising new tool for improving the diagnostic examination of patients with suspicion of LC. Detection of epithelial cells with a higher DNA content is highly specific of LC, but evaluation of the nonepithelial cell compartment of the CSF might also be useful for supporting this diagnosis.
authors: Department of Hematology, Hospital de Guadalajara, Guadalajara, Spain. dosuperez@yahoo.es
authors: Dolores
authors: D
authors: Subirá
authors: Cristina
authors: C
authors: Serrano
authors: Susana
authors: S
authors: Castañón
authors: Raquel
authors: R
authors: Gonzalo
authors: Julia
authors: J
authors: Illán
authors: Javier
authors: J
authors: Pardo
authors: María
authors: M
authors: Martínez-García
authors: Esther
authors: E
authors: Millastre
authors: Francisco
authors: F
authors: Aparisi
authors: Miguel
authors: M
authors: Navarro
authors: Manuel
authors: M
authors: Dómine
authors: Ignacio
authors: I
authors: Gil-Bazo
authors: Pedro
authors: P
authors: Pérez Segura
authors: Miguel
authors: M
authors: Gil
authors: Jordi
authors: J
authors: Bruna
mesh_terms: D000368:Aged; D000951:Antigens, Neoplasm / Q000134:cerebrospinal fluid; D015815:Cell Adhesion Molecules / Q000134:cerebrospinal fluid; D004273:DNA, Neoplasm / Q000032:analysis; D000071858:Epithelial Cell Adhesion Molecule; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D016130:Immunophenotyping / Q000379:methods*; D008297:Male; D055756:Meningeal Carcinomatosis / Q000134:cerebrospinal fluid* / Q000175:diagnosis*; D008875:Middle Aged; D009375:Neoplasms, Glandular and Epithelial / Q000134:cerebrospinal fluid* / Q000175:diagnosis*; D011237:Predictive Value of Tests; D012189:Retrospective Studies
chemical_list: D000951:Antigens, Neoplasm; D015815:Cell Adhesion Molecules; D004273:DNA, Neoplasm; C499379:EPCAM protein, human; D000071858:Epithelial Cell Adhesion Molecule