Double cancer in a 74-year-old woman: a case report with genetic findings.

An autopsy case of double cancer is reported. The patient had undergone right hemicolectomy for colon carcinoma in 1982, and the second cancer was detected in the pancreas in April 1989, which was diagnosed as intraductal papillary adenocarcinoma that is known for its favorable prognosis after surgical resection. However, as the patient did not consent to the operation, she died in August 1994, five years after the diagnosis of the second cancer. Histopathological study revealed neither recurrence nor metastasis of colon carcinoma. The pancreatic carcinoma metastasized to the lung, liver, and peritoneum. DNAs were extracted from paraffin-embedded tissue for molecular pathological examinations. Different mutations were found at codon 12 of the K-ras gene by nucleotide sequencing analysis: one in the colon and the other in the pancreas and lung. Over-expression of p53 protein was also detected in the colon by immunostaining. Replication error was not observed in these three tumors suggesting that a factor(s) other than genetic instability was playing a role in the development of double cancer in this patient.