Purpose: Hereditary nonpolyposis colorectal cancer kindreds are frequently associated with cancers in various organs, including endometrium, stomach, and ovary. However, hematologic malignancy has rarely been reported in association with this cancer syndrome. We present here the case of a probable hereditary nonpolyposis colon cancer patient in whom non-Hodgkin's lymphoma developed after curative resection of colon cancer. Our experience with this rare case encouraged us to review the literature for reports indicating a possible relationship between these diseases.
Results: A 52-year-old male whose family history was consistent with the criteria for hereditary nonpolyposis colon cancer underwent right hemicolectomy for ascending colon cancer. Histologically the tumor consisted of adenocarcinoma that was moderately differentiated with mucinous foci and that invaded beyond the muscularis propria. Neither metastasis nor lymphoma was found in paracolonic lymph nodes. Eight months after surgery, the patient developed non-Hodgkin's lymphoma of T-cell origin involving the ileum and lungs. Both colon cancer and lymphoma frequently showed microsatellite DNA instability, sharing alteration in a locus of chromosome 7 (D7S501).
Conclusion: A possible association of hematologic malignancy with hereditary nonpolyposis colon cancer reported in the literature, together with a report that MSH2-deficient mice are susceptible to malignant lymphoma, strongly supports the finding that this patient's lymphoma was related to hereditary nonpolyposis colon cancer. Overall, this case manifested a distinct clinical course similar to that observed in an animal model that is deficient in DNA mismatch repair machinery, thus providing scientific and clinical implications for understanding the molecular basis of these tumors and for critical management of hereditary nonpolyposis colorectal cancer patients, respectively.