title: Endoscopic ultrasound and fine needle aspiration in chronic pancreatitis: differential diagnosis between pseudotumoral masses and pancreatic cancer.
abstract: BACKGROUND
  Pseudotumoral chronic pancreatitis can be difficult to differentiate from pancreatic carcinoma.
  
  
  OBJECTIVE
  To evaluate the role of endoscopic ultrasound and fine needle aspiration in differentiating between inflammatory masses and malignancies in chronic pancreatitis.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  Tertiary care endoscopy unit.
  
  
  METHODS
  Between February 1997 and December 2006, 69 pancreatic head masses from patients with alcoholic chronic pancreatitis underwent EUS-FNA using a linear echoendoscope and 22-gauge needles. Final diagnoses were obtained from surgery or clinical follow-up. The patients were subdivided into two groups: pseudotumoral chronic pancreatitis and pancreatic cancer.
  
  
  RESULTS
  Pseudotumoral masses and adenocarcinoma were found in 58 and 11 patients, respectively. The size of the lesions and the clinical presentation were similar in both groups, but the cancer patients were older than the patients with pseudotumoral masses (P=0.020). Fourteen of the 58 (24.1%) pseudotumoral masses were misdiagnosed as cancers, and 4 of the 11 (36.4%) cancers were erroneously diagnosed as pseudotumoral masses when evaluated by EUS alone. EUS-FNA confirmed the final diagnosis in 66 of the 69 (95.7%) cases. Cytopathology correctly classified 8 of the 11 (72.7%) malignancies and all benign cases. Three of the 11 (27.3%) cancers were misdiagnosed as pseudotumoral masses, and no pseudotumoral mass was diagnosed as a cancer. In two cases, the specimens were inadequate for cytopathological assessment. The sensitivity, specificity, positive and negative predictive values, and the diagnostic accuracy of EUS-FNA were 72.7%, 100%, 100%, 95.1% and 95.7%, respectively.
  
  
  CONCLUSIONS
  The diagnostic accuracy of endoscopic ultrasound alone for differentiating between pseudotumoral masses and pancreatic cancer arising from chronic pancreatitis is unsatisfactory. Fine needle aspiration of these tumors significantly improves diagnostic capability.
authors.affiliation: Echoendoscopy Unit, 9 de Julho Hospital, University of São Paulo. São Paulo, Brazil. jcelso@uol.com.br
authors.forename: José Celso
authors.initials: JC
authors.lastname: Ardengh
authors.forename: César Vivian
authors.initials: CV
authors.lastname: Lopes
authors.forename: Antônio Dorival
authors.initials: AD
authors.lastname: Campos
authors.forename: Luiz Felipe
authors.initials: LF
authors.lastname: Pereira de Lima
authors.forename: Filadélfio
authors.initials: F
authors.lastname: Venco
authors.forename: José Luiz Pimenta
authors.initials: JL
authors.lastname: Módena
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044963:Biopsy, Fine-Needle; D003937:Diagnosis, Differential; D016145:Endoscopy, Digestive System; D019160:Endosonography; D005260:Female; D005500:Follow-Up Studies; D006104:Granuloma, Plasma Cell / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D050500:Pancreatitis, Chronic / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D012189:Retrospective Studies; D012680:Sensitivity and Specificity