Metastases in the pancreas from nonhematologic neoplasms: report of 20 cases evaluated by fine-needle aspiration.

We reviewed fine-needle aspiration (FNA) samples of metastatic tumor in the pancreas from nonhematologic neoplasms over a 5-year period. In 1,050 total procedures, 20 metastases were diagnosed: 9 renal-cell carcinomas (RCCs), 3 melanomas, 2 pulmonary small-cell carcinomas, 2 breast carcinomas, 1 prostate carcinoma, 1 colon adenocarcinoma, 1 pulmonary squamous-cell carcinoma, and 1 gastrointestinal stromal tumor. A wide range of latency from primary diagnosis was noted; the longest was RCC at 12.6 years (range, 5-28). Sites of involvement were: 13 heads, 4 bodies, and 3 tails. Eighteen cases presented as a solitary mass. The average size was 4.7 cm (range, 1.5-9.8), and a case of RCC (9.8 cm) was the largest. In seven cases, the clinical and radiographic impression was of a pancreatic primary. We conclude that metastases to the pancreas are rarely diagnosed by FNA and may clinically mimic a pancreatic primary. 2004 Wiley-Liss, Inc.