title: Association of cytologic micropapillary clusters in cytology samples with lymphatic spread in clinical stage I lung adenocarcinomas.
abstract: OBJECTIVE
  Cytologic micropapillary clusters (MPCs) are round, three-dimensional and cohesive clusters of lung cancer cells with a pseudopapillary configuration. Recently, we demonstrated that MPCs from early stage lung adenocarcinomas can be considered as useful aids to assessing prognosis. We here demonstrate that stage I lung adenocarcinomas found to be positive for MPCs in preoperative cytologic approaches are high risk for lymphatic spread.
  
  
  METHODS
  The clinicopathologic characteristics, metastatic status of dissected lymph nodes, vascular infiltration and presence of MPCs in preoperative cytologic specimens in 209 patients with clinical stage I lung adenocarcinomas undergoing complete surgical resection during 2004-2006 were reviewed.
  
  
  RESULTS
  Thirty-eight patients (18%) had positive MPC findings; 21 patients with clinical stage IA and 17 with stage IB. Significant associations with postoperative stages IA and IB, frequent lymph node metastasis and venous infiltration on pathologic examination were observed (P<0.05). In particular, 50% of clinical stage I patients with MPCs demonstrated advance in the postoperative stage of disease.
  
  
  CONCLUSIONS
  MPCs may be a manifestation of aggressive behavior, as evidenced by frequent lymph node metastasis, of clinical stage I lung adenocarcinomas. Preoperative cytologic detection of MPCs, therefore, should alert the surgeon to the probability of lymph node metastases.
authors.affiliation: Department of Cytology, The Cancer Institute Hospital, The Japanese Foundation for Cancer Research, Japan. ysatoh@med.kitasato-u.ac.jp
authors.forename: Yukitoshi
authors.initials: Y
authors.lastname: Satoh
authors.forename: Rira
authors.initials: R
authors.lastname: Hoshi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Horai
authors.forename: Sakae
authors.initials: S
authors.lastname: Okumura
authors.forename: Ken
authors.initials: K
authors.lastname: Nakagawa
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ishikawa
authors.forename: Satoshi
authors.initials: S
authors.lastname: Miyata
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000473:pathology* / Q000601:surgery; D000368:Aged; D003584:Cytological Techniques; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012907:Smoking