title: Cytomorphological features of blastic plasmacytoid dendritic cell neoplasm on FNA and cerebrospinal fluid cytology: A review of 6 cases.
abstract: BACKGROUND
  Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematopoietic tumor that was once believed to be derived from natural killer cells and is now recognized as originating from precursors of plasmacytoid dendritic cells. It generally involves the skin and has an aggressive clinical course. Due to its highly malignant behavior, a fast and accurate diagnosis of this condition is of the utmost importance.
  
  
  METHODS
  Six cytology specimens from 5 patients diagnosed with BPDCN were reviewed as well as their clinical records. Findings were compared with 3 previously published cases.
  
  
  RESULTS
  Two exfoliative cytology specimens (cerebrospinal fluid) and 4 fine-needle aspiration specimens (3 lymph node specimens and 1 cutaneous specimen) were reviewed. The cytomorphological aspects were similar in all cases. The smears were hypercellular with a monotonous population of intermediate-sized cells, dispersed singly or arranged in loose aggregates. The cells had round to oval nuclei, with fine chromatin and prominent nucleoli; the cytoplasm was generally scant, without visible granules. Intracytoplasmic microvacuoles were found in the majority of cases. Four cases were also characterized by flow cytometry, which revealed expression of CD 123, CD56 and/or CD4. Fine-needle aspiration was used in 1 case for primary diagnosis. Histological confirmation was available in all cases.
  
  
  CONCLUSIONS
  BPDCN is a highly malignant neoplasm with a poor outcome. Cytology, in association with flow cytometry immunophenotyping and clinical history, is a reliable method with which to establish the diagnosis.
authors.affiliation: Pathology Department, Instituto Portugues de Oncologia de Lisboa Francisco Gentil, Lisbon, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Ferreira
authors.affiliation: Pathology Department, Fernando Fonseca Hospital, Hospital Fernando da Fonseca, Amadora, Portugal.
authors.forename: Maria Gabriela
authors.initials: MG
authors.lastname: Gasparinho
authors.affiliation: Pathology Department, Instituto Portugues de Oncologia de Lisboa Francisco Gentil, Lisbon, Portugal.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Fonseca
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D044963:Biopsy, Fine-Needle; D002555:Cerebrospinal Fluid / Q000166:cytology*; D003713:Dendritic Cells / Q000473:pathology*; D005260:Female; D006801:Humans; D007938:Leukemia / Q000134:cerebrospinal fluid / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012878:Skin Neoplasms / Q000134:cerebrospinal fluid / Q000473:pathology*
keywords: cerebrospinal fluid; dendritic cells; fine-needle biopsy; leukemia; plasmacytoid