title: Chylothorax as a possible diagnostic pitfall: a report of 2 cases with cytologic findings.
abstract: BACKGROUND
  Chyothorax is an uncommon medical condition. To the best of our knowledge, there have been no detailed English-language report dealing with its cytopathologic findings and diagnostic pitfalls
  
  
  METHODS
  A 12-year-old boy, hemodialysis dependent, with congenital nephrotic syndrome due to focal segmental glomerular sclerosis and a failed renal transplant, developed shortness of breath. Physical and radiologic examinations revealed a left pleural effusion. A 7-year-old boy developed shortness of breath, with a subsequent finding of a left pleural effusion. Multiple osteolytic skeletal lesions were found in this patient. Both patients underwent thoracocentesis. Cytologically, both fluids contained many relatively uniform, large lymphoid cells with high nuclear/cytoplasmic (N/C) ratio, condensed chromatin and occasional nucleoli, resembling blasts. Some nuclei were convoluted. Mitotic figures were present. Foamy macrophages were present in both cases. The differential diagnosis of these populations of cells included a lymphoproliferative disorder. However, the mature T-lymphocytic nature of the cells was confirmed by immunohistochemistry performed on cell block preparations, confirming the clinical impression of chylothorax in both cases. The first patient had chylothorax as a result of trauma due to therapeutic interventions (subclavian vein cannulation), in the second patient the chylothorax was a part of Gorham-Stout syndrome.
  
  
  CONCLUSIONS
  The large T-lymphocytes that are the major cellular component of chylothorax may arouse suspicion of a lymphoproliferative disorder. Attention to the clinical history and immunophenotyping confirm the benign nature of the pleural space fluid. Also, abundant foamy macrophages can be considered a low-power clue to this diagnosis.
authors.affiliation: Department of Pathology, University Hospital Brno, Brno, Czech Republic.
authors.forename: Leos
authors.initials: L
authors.lastname: Kren
authors.forename: Pavla
authors.initials: P
authors.lastname: Rotterova
authors.forename: Marketa
authors.initials: M
authors.lastname: Hermanova
authors.forename: Zdenka
authors.initials: Z
authors.lastname: Krenova
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Sterba
authors.forename: Karel
authors.initials: K
authors.lastname: Dvorak
authors.forename: Viktor
authors.initials: V
authors.lastname: Goncharuk
authors.forename: George D
authors.initials: GD
authors.lastname: Wilner
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: McKenna
mesh_terms: D002648:Child; D002916:Chylothorax / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*; D003937:Diagnosis, Differential; D006801:Humans; D007150:Immunohistochemistry; D008232:Lymphoproliferative Disorders / Q000175:diagnosis; D008297:Male; D013601:T-Lymphocytes / Q000378:metabolism / Q000473:pathology*