Endoscopic Ultrasound (EUS)-Guided Fine Needle Aspiration of Metastatic Malignancies Involving the Pancreas: A Single-Institution 10-Year Retrospective Study of 46 Cases
Shaoxiong Chen, Xiaoyan Wang, Harvey Cramer. Indiana University, Indianapolis
Background: Metastatic malignancies involving the pancreas are relatively uncommon compared to primary pancreatic neoplasms. Documentation of metastases to the pancreas by fine needle aspiration (FNA) sometimes obviates the need for surgery entirely and allows the oncologist to institute the appropriate course of medical treatment.
Design: A computerized search of our laboratory information system was performed for the 10-year period from April 2001 through March 2011 to identify all metastatic neoplasms involving the pancreas diagnosed by FNA. All correlating surgical pathology reports were also reviewed and the microscopic slides from selected cases were re-examined.
Results: Over the 10-year period encompassed by this study, a total of 4369 FNAs of the pancreas were performed at our institution which included 1445 cases of pancreatic ductal adenocarcinomas (33%) and only 46 cases of metastatic malignancies involving the pancreas (1%). The male to female ratio was 1:1.7. The metastatic lesions ranged in size from 1.2 to 6.0 cm with a mean of 3.2 cm. There were 13 cases diagnosed by FNA as metastatic renal cell carcinoma (RCC), 2 cases diagnosed as suspicious for metastatic RCC and 2 cases of primary pancreatic adenocarcinoma that were misclassified as metastatic RCC. One of the misclassified cases had a prior history of RCC while the other patient presented with synchronous pancreatic and renal masses. There were 12 cases of metastatic small cell carcinoma originating from a lung primary, 7 cases of metastatic adenocarcinomas originating from breast (3), colon (3) and esophagus (1) and 4 cases of metastatic melanoma originating from primaries in the arm (2), gallbladder (1) and unknown site (1). The remaining 6 metastatic malignancies included neuroendocrine carcinoma from a head and neck primary (2), urothelial carcinoma arising from a renal primary (1), squamous carcinoma from the anus (1), low grade sarcoma from the thigh (1) and a leiomyosarcoma from the abdomen (1). Immunocytochemical staining was performed in only 4 of these 46 cases, and histopathologic follow-up was obtained in only 10 cases.
Conclusions: Metastatic lesions to the pancreas are relatively uncommon. The most common metastatic tumors to the pancreas are RCC, small cell carcinoma of pulmonary origin, adenocarcinoma and melanoma. The 2 diagnostic errors (4%) suggest that clinical data can sometimes adversely influence cytomorphologic interpretation and that perhaps more frequent utilization of appropriate immunostains could conceivably reduce our error rate.
Tuesday, March 20, 2012 9:30 AM
Poster Session III # 65, Tuesday Morning