Diagnosis of Metastasis to the Pancreas by Fine Needle Aspiration Biopsy.
Kenneth E Youens, Sarah M Bean. Duke University Medical Center, Durham, NC
Background: Correctly distinguishing primary tumors of the pancreas from metastases to the pancreas is important, given the sometimes widely different treatment regimens. However, metastases to the pancreas are relatively uncommon, and little information is available in the literature. Here we report the twenty-year experience of cytological diagnosis of pancreatic metastases.
Design: All cases diagnosed by endoscopic ultrasound-guided (EUS) fine needle aspiration (FNA), computed tomography (CT)-guided percutaneous FNA, and ultrasound-guided percutaneous FNA between January 1, 1990 and March 30, 2010 with the diagnosis of metastases to the pancreas were identified by searching the clinical database. Imaging and pathologic features were collated.
Results: We identified 57 cases of metastasis to the pancreas. Thirty-seven specimens were obtained by EUS-FNA, thirteen by CT-guided percutaneous biopsy, and seven by ultrasound-guided percutaneous biopsy. In order of decreasing frequency, the primary site was identified as hematopoietic (21), kidney (11), lung (7), skin (6), ovary (3), breast (2), soft tissue (2), esophagus (2), colon (1), nasopharynx (1), or prostate (1). The five most common tumors to metastasize to the pancreas were, in descending order, non-Hodgkin B-cell lymphoma, renal cell carcinoma, melanoma, neuroendocrine carcinoma of the lung, and adenocarcinoma of the ovary. In 46% of cases (26 of 57), the pre-biopsy imaging findings favored metastasis. In 19% of cases (11 of 57), metastasis was not favored by the imaging findings, and in the remaining 35% cases (20 of 57), the suspected primary site was either equivocal or was unspecified. In 81% of cases (46 of 57), the pancreatic tumor was able to be definitively classified as metastatic after cytopathologic evaluation, while the remaining 19% (11 of 57), mostly comprised of poorly-differentiated carcinomas of uncertain histogenesis or of scant specimens unable to be definitively classified, were considered to be probable metastases. Of these eleven cases, histological follow up was unavailable for nine, while two had histological confirmation as metastases.
Conclusions: Metastases to the pancreas are infrequent and are not always classifiable as such by imaging. Cytopathologic evaluation is useful in distinguishing primary from metastatic tumors of the pancreas in the majority of cases.
Tuesday, March 1, 2011 9:30 AM
Poster Session III # 69, Tuesday Morning