title: Mantle cell lymphoma of the rectum at an early stage: a case report.
abstract: We report a very rare early-stage case of mantle cell lymphoma, which arose from the rectum. A 60-year-old man presented with a small elastically hard polypoid lesion in the rectum. The lesion was 1.2 x 1.2 cm in size. As a preoperatively barium enema and endoscopy suggested a benign tumor of the rectum, he underwent local excision of a rectal polypoid mass transanally under spinal anesthesia. However, histological examination revealed a malignant lymphoma, because the lesion was histologically characterized by solid growths of small to medium-sized round cells. Furthermore, immunohistochemical tests revealed B-cell marker positivity and CD5 positivity, but cyclin D1 negativity. Since it was reported that lymphomas with a mantle cell lymphoma morphology and CD5 expression, but without cyclin D1 overexpression, exist in about 10% of mantle cell lymphoma cases, we diagnosed his disease as mantle cell lymphoma. To our knowledge, this is the first reported case of an early-stage mantle cell lymphoma, originating from the rectum.
authors.affiliation: First Department of Surgery, Nara Medical University, 840 Shijou-chou, Kashihara, Nara, 634-0813, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Terauchi
authors.forename: K
authors.initials: K
authors.lastname: Yamamoto
authors.forename: H
authors.initials: H
authors.lastname: Fujii
authors.forename: F
authors.initials: F
authors.lastname: Koyama
authors.forename: S
authors.initials: S
authors.lastname: Sugimori
authors.forename: H
authors.initials: H
authors.lastname: Enomoto
authors.forename: M
authors.initials: M
authors.lastname: Yamanouchi
authors.forename: H
authors.initials: H
authors.lastname: Nakano
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis; D003113:Colonoscopy; D003937:Diagnosis, Differential; D019160:Endosonography; D006801:Humans; D020522:Lymphoma, Mantle-Cell / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012004:Rectal Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D012007:Rectum / Q000473:pathology / Q000601:surgery
chemical_list: D014408:Biomarkers, Tumor