title: Focal organizing pneumonia on surgical lung biopsy: causes, clinicoradiologic features, and outcomes.
abstract: BACKGROUND
  Organizing pneumonia (OP) is a histologic pattern that is morphologically distinctive but nonspecific and can be seen in diverse clinical settings. Focal OP has been described as a discrete form of OP, but relatively little is known regarding this clinicopathologic entity.
  
  
  METHODS
  We sought to clarify the clinicoradiologic presentation, underlying causes, and outcomes associated with focal OP by retrospectively reviewing 26 consecutive cases diagnosed by surgical lung biopsy over an 8-year period from January 1, 1997, to December 31, 2004.
  
  
  RESULTS
  All patients presented with an unifocal opacity detected on chest radiography (20 patients) or CT scans (6 patients). At the time of presentation, 10 patients (38%) had symptoms, including cough, shortness of breath, or chest pain; 16 patients were asymptomatic. Contrast-enhancement CT scanning or positron emission tomography (PET) scan was performed in 11 patients, and the results were positive in all. Surgical procedures included wedge resection in 21 patients (81%), segmentectomy in 3 patients (11%), and lobectomy in 2 patients (8%). Three case of focal OP (12%) were related to infections, but the remaining cases were cryptogenic. Follow-up over a median interval of 11 months (range, 1 to 71 months) yielded no recurrence of OP.
  
  
  CONCLUSIONS
  The radiologic features of focal OP are often indistinguishable from those of lung cancer, and include positivity on contrast-enhancement CT scan and PET scan. Most cases of focal OP are cryptogenic, and infection is identified in a minority of cases. Surgical resection alone appears to suffice in the management of cryptogenic focal OP.
authors: Division of Pulmonary and Critical Care Medicine, Department of Laboratory Medicine and Pathology, Desk East 18, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA.
authors: Fabien
authors: F
authors: Maldonado
authors: Craig E
authors: CE
authors: Daniels
authors: Elizabeth A
authors: EA
authors: Hoffman
authors: Eunhee S
authors: ES
authors: Yi
authors: Jay H
authors: JH
authors: Ryu
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D001999:Bronchoscopy; D003287:Contrast Media; D018549:Cryptogenic Organizing Pneumonia / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013902:Radiography, Thoracic; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media