Double minutes in human large bowel cancer.

Two patients with large bowel carcinoma are described in whose tumors the presence of double minutes was observed. In one of these, the first such patient to be reported, double minutes were present in 100% of metaphases examined in both the primary tumor and its liver metastasis. The number of double minutes varied from 6 to 93 per metaphase. In the second patient, double minutes were seen only in two metaphases. The literature on double minutes is summarized, and it is concluded that double minutes are found in a wide spectrum of tumors, including human large bowel cancer and are not confined to tumors of neurogenic origin as suggested by earlier workers. In additon, evidence is suggestive of an association between the lack of differentiation and the presence of double minutes, but further data are required to substantiate this.