Surgical treatment of pancreatic metastases: More appropriate surgical methods based on a clinicopathologic study of 43 patients.

PURPOSE: There is no established surgical method for metastatic lesion to the pancreas. In the case of relatively small lesion, we often hesitate to select which surgical method, that is, wedge/partial resection or Whipple/distal pancreatectomy. Moreover, it is debatable whether lymph node dissection is necessary or not. We investigated clinicopathological characteristics in order to resolve the above problems.

METHODS

Forty-three patients underwent pancreatic resection for metastatic tumors in Cancer Institute of the Japanese Foundation for Cancer Research, whose specimens were investigated clinicopathologically.

RESULTS

Primary tumors included renal cell carcinoma(RCC), colorectal carcinoma (CRC), and miscellaneous malignancy (MM) in 23, 9, and 11 cases, respectively. Plural metastases in a resected specimen or mpd, i.e., tumor extension into the main pancreatic duct (MPD) was observed in eleven (26%, 11/43) or 9 (21%, 9/43) patients, respectively. Five of 9 mpd cases had more over 2 cm intraductal tumor extention from the main metastatic lesion. Lymph node metastasis surrounding the main metastasis was observed in 11 patients (5 CRCs, 5 MMs, and 1 RCC), with a metastatic rate to lymph node of 56% (5/9), 45% (5/11), and 4% (1/23) for CRCs, MMs, and RCCs, respectively.

CONCLUSIONS

1) Wedge or partial resection of the pancreas for metastatic tumor should not be easily chosen, because of positive resection margin due to mpd and/or leaving another metastatic lesion. 2) Lymph node dissection is not strictly necessary for the surgical removal of pancreatic metastasis from RCC, whereas this is highly recommended for patients with metastasis from CRC or MM.