title: Endoscopic ultrasound-guided fine-needle aspiration diagnosis of secondary tumors involving the pancreas: An institution's experience.
abstract: BACKGROUND
  Pancreatic masses may seldom represent a metastasis or secondary involvement by lymphoproliferative disorders. Recognition of this uncommon occurrence may help render an accurate diagnosis and avoid diagnostic pitfalls during endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). In this study, we review our experience in diagnosing secondary tumors involving the pancreas.
  
  
  METHODS
  The electronic database of cytopathology archives was searched for cases of secondary tumors involving the pancreas at our institution and a total of 31 cases were identified. The corresponding clinical presentations, imaging study findings, cytological diagnoses, the results of ancillary studies, and surgical follow-up, if available, were reviewed.
  
  
  RESULTS
  Nineteen of the patients were male and 12 female, with a mean age of 66 years. Twenty-three patients (74%) had a prior history of malignancy, with the latency ranging from 6 months to 19 years. The secondary tumors involving the pancreas included metastatic carcinoma (24 cases), metastatic sarcoma (3 cases), diffuse large B-cell lymphoma (2 cases), and plasma cell neoplasm (2 cases). The most common metastatic tumors were renal cell carcinoma (8 cases) and lung carcinoma (7 cases). Correct diagnoses were rendered in 29 cases (94%). The remaining two cases were misclassified as primary pancreatic carcinoma. In both cases, the patients had no known history of malignancy, and no ancillary studies were performed.
  
  
  CONCLUSIONS
  Secondary tumors involving the pancreas can be accurately diagnosed by EUS-FNA. Recognizing uncommon cytomorphologic features, knowing prior history of malignancy, and performing ancillary studies are the keys to improve diagnostic performance and avoid diagnostic pitfalls.
authors.affiliation: Address: Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA.
authors.forename: Almed K
authors.initials: AK
authors.lastname: Alomari
authors.affiliation: Address: Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA.
authors.forename: Berrin
authors.initials: B
authors.lastname: Ustun
authors.affiliation: Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.
authors.forename: Harry R
authors.initials: HR
authors.lastname: Aslanian
authors.affiliation: Address: Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA.
authors.forename: Xinquan
authors.initials: X
authors.lastname: Ge
authors.affiliation: Address: Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA.
authors.forename: David
authors.initials: D
authors.lastname: Chhieng
authors.affiliation: Address: Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA.
authors.forename: Guoping
authors.initials: G
authors.lastname: Cai
keywords: Ancillary study; endoscopic ultrasound; fine-needle aspiration; pancreas; secondary tumor