Published online Aug 26, 2023. doi: 10.12998/wjcc.v11.i24.5772
Peer-review started: May 12, 2023
First decision: May 31, 2023
Revised: June 18, 2023
Accepted: July 11, 2023
Article in press: July 11, 2023
Published online: August 26, 2023
Processing time: 104 Days and 17.8 Hours
Mantle cell lymphoma (MCL) of the gastrointestinal tract is a rare malignancy, accounting for about 0.2% of malignant colorectal tumors. MCL synchronous with rectal adenocarcinoma is extremely rare. We know of only a few cases reported in the literature. We describe the case of a patient with synchronous rectal adenocarcinoma and intestinal MCL.
A 63-year-old man was admitted to our hospital due to abdominal pain and hematochezia over the past month. The patient was diagnosed with middle rectal cancer cT2N0M0 and underwent surgery. However, we found a large tumor in the small intestine during surgery. The patient underwent total mesorectal excision for rectal cancer and resectioning of the ileal segment containing the large mass. Pathology and immunohistochemistry revealed the presence of both rectal adenocarcinoma and pathognomonic MCL stage IIE presenting as multiple lymphomatous polyposis. The patient subsequently underwent RDHAP/RCHOP chemotherapy and was maintained with rituximab. A Positron Emission Tomography and Computed Tomography (PET/CT) scan showed that the disease responded well to treatment without tumor-increased metabolism in the gastrointestinal tract.
Synchronous rectal adenocarcinoma and intestinal MCL presenting as multiple lymphomatous polyposis are extremely rare. MCL is often discovered fortuitously when rectal cancer is diagnosed. The coexistence of these tumors poses treatment challenges.
Core Tip: Mantle cell lymphoma (MCL) of the gastrointestinal tract is an uncommon malignancy. Rectal adenocarcinoma is more common, but the coexistence of both is extremely rare. Their diagnosis should be based on histopathological and immunohistochemical features. MCL is a typically aggressive disease and has a poorer prognosis than adenocarcinoma. The treatment of two different simultaneously occurring cancers is a challenge, as it depends on the stage, prognosis, and response of each disease to treatment.