title: Fine needle aspiration cytology of metastatic olfactory neuroblastoma: a case report.
abstract: BACKGROUND
  Olfactory neuroblastoma (ONB) is an uncommon tumor, presenting as a polypoid mass arising from the upper nasal cavity. This tumor has been seldom diagnosed by direct fine needle aspiration (FNA).
  
  
  METHODS
  Metastatic ONB was diagnosed by FNA. The patient was a 40-year-old female with a polypoid mass in the nasal cavity and ipsilateral cervical lymphadenopathy. The punch biopsy of the nasal tumor revealed a smudged small round cell neoplasm with neuroendocrine differentiation, consistent with ONB. In FNA smears from the cervical lymph node, there were well-preserved, small, monotonous cells with hyperchromatic nuclei, fibrillary cytoplasm and indistinct cell borders. Also noteworthy were occasional pseudorosettes as well as rare true rosettes. By immunocytochemistry, tumor cells were positive for cytokeratin, chromogranin and synaptophysin.
  
  
  CONCLUSIONS
  ONB, like adrenal neuroblastoma, shows distinctive cytologic features, including a rosette or pseudorosette and fibrillary network. FNA can accurately demonstrate these characteristic findings, and in some cases it may be a better diagnostic modality than incisional biopsy.
authors.affiliation: Department of Diagnostic Pathology, Asan Kangnung Hospital, KangNungSi, South Korea. gzz@ghil.com
authors.forename: Jaegul
authors.initials: J
authors.lastname: Chung
authors.forename: Seon Tae
authors.initials: ST
authors.lastname: Park
authors.forename: Jaejung
authors.initials: J
authors.lastname: Jang
mesh_terms: D000328:Adult; D001707:Biopsy, Needle; D018304:Esthesioneuroblastoma, Olfactory / Q000473:pathology* / Q000556:secondary; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D009296:Nasal Cavity; D009669:Nose Neoplasms / Q000473:pathology*