OBJECTIVETo report a case of rectal non-Hodgkin lymphoma with concomitant rectal adenocarcinoma.

METHODSClinical records of a 71 years old male patient with rectal non-Hodgkin lymphoma with concomitant rectal adenocarcinoma admitted on May 19, 2010 to the First Affiliated Hospital of Sun Yet-sen University were retrospectively reviewed. Clinical manifestations, diagnosis, and treatment as well as postoperative pathology were summarized.

RESULTSThe preoperative diagnosis of the patient was severe atypical adenomatous hyperplasia with focal carcinogenesis, and the preoperative staging was T2N0-1M0. The patient underwent a Parks procedure (rectal resection and colo-anal anastomosis) and subtotal resection of left lateral liver. The operation was successful, postoperative recovery uneventful. Postoperative pathology showed moderately differentiated tubular adenocarcinoma with deep muscular invasion, and non-Hodgkin lymphoma with marginal zone cell. Both the distal and proximal resection margins were negative and no vascular and neural invasion were seen. Immunohistochemical staining indicated L26(+), Bcl-2(+), Bcl-6(+), CD3(-), CD23(-), CK epithelial cells(+), and M-CEA luminal border(+). The pathological and immunohistochemistry results of liver specimens showed hepatic mucosa-associated marginal zone lymphoma.

CONCLUSIONSRectal adenocarcinoma and lymphoma occurring at the same site simultaneously is extremely rare with unique pathologic features.