title: Primary malignant lymphoma of the rectum with diagnostic problems. Report of two cases with an analysis of gene rearrangement.
abstract: We present two similar cases of rectal B-cell lymphoma with diagnostic problems. Grossly, both tumors appeared as a well demarcated polypoid mass with eroded mucosa. In spite of their histologic resemblance to reactive lymphoid hyperplasia, including the presence of lymph follicles, fibrosis and polyclonal plasma cells, both cases were diagnosed as malignant lymphoma of low-grade malignancy because of the full-thickness involvement of the rectum with diffusely infiltrated small or medium-sized lymphoid cells showing rare mitoses. In one case, clonal proliferation of differentiated B cells was demonstrated by analysis of gene rearrangement. Therapeutic problems related to low-grade malignant lymphoma in the rectum are also discussed.
authors.affiliation: Department of Pathology, Uwajima City Hospital, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kurihara
authors.forename: K
authors.initials: K
authors.lastname: Mizuseki
authors.forename: A
authors.initials: A
authors.lastname: Iwashita
authors.forename: M
authors.initials: M
authors.lastname: Ichikawa
authors.forename: S
authors.initials: S
authors.lastname: Kajiwara
authors.forename: M
authors.initials: M
authors.lastname: Ohtoshi
mesh_terms: D000328:Adult; D000368:Aged; D001402:B-Lymphocytes / Q000473:pathology; D015139:Blotting, Southern; D004273:DNA, Neoplasm / Q000235:genetics; D003937:Diagnosis, Differential; D005260:Female; D015322:Gene Rearrangement, B-Lymphocyte / Q000235:genetics*; D006801:Humans; D016393:Lymphoma, B-Cell / Q000175:diagnosis* / Q000235:genetics* / Q000473:pathology; D008297:Male; D012004:Rectal Neoplasms / Q000175:diagnosis* / Q000235:genetics* / Q000473:pathology
chemical_list: D004273:DNA, Neoplasm