LAUSR

INTRODUCTION Metastases that present as pancreatic masses are rare. Understanding and recognizing this uncommon occurrence during endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) will help in making an accurate diagnosis and planning for clinical management. In this study, we reviewed our experience in diagnosing pancreatic secondary tumors. MATERIALS AND METHODS A pathology archive database search was performed for EUS-FNAs of the pancreas with a diagnosis of metastatic tumor at our institution. The corresponding clinical presentations, imaging studies, cytological diagnoses, ancillary studies, and surgical follow-up were collected. RESULTS A total of 30 cases were identified with 18 male and 12 female patients. Twenty-eight patients (93.3%) had a prior history of malignancy, with a latency ranging from 0 to 36 years. The secondary tumors included carcinoma (18 of 30), neuroendocrine tumor (5 of 30), melanoma (4 of 30), and sarcoma (3 of 30). The most common metastatic tumor was clear cell renal cell carcinoma (37%, 11 of 30). Correct diagnoses were rendered in 28 cases (93.3%). The remaining 2 cases failed to be accurately diagnosed: one pleomorphic carcinoma (reported as pleomorphic sarcoma) and one liposarcoma (reported as poorly differentiated malignant neoplasm). Both cases did not have immunohistochemistry performed because of a lack of diagnostic materials in cell blocks. CONCLUSIONS Our data demonstrated that metastatic clear cell renal cell carcinoma was the most common secondary tumor involving the pancreas. Secondary tumors involving the pancreas can be accurately diagnosed by EUS-FNA. Knowing the prior history of malignancy, recognizing uncommon cytomorphologic features, and performing ancillary studies are keys to improve diagnostic accuracy.