Non-multiple lymphomatous polyposis form of mantle cell lymphoma in the gastrointestinal tract.

Mantle cell lymphoma (MCL) comprises 2.5%-7% of all non-Hodgkin's lymphomas, and the gastrointestinal tract is involved in about 20% of cases. Multiple lymphomatous polyposis (MLP) is an uncommon disease that is regarded as the intestinal form of MCL. We present a rare case of gastrointestinal MCL without MLP, and demonstrate that rituximab was effective for the treatment of this patient. A 61-year-old man presented with continuous diarrhea and hematochezia for a period of 5 months. Superficial lymph nodes were not palpable, but both tonsilla were enlarged. The level of soluble interleukin (IL)2-receptor was 3480 U/ml (normal <500 U/ml). Colonoscopy showed diffuse redness with erosion, without observation of any venous capillary, with these findings continuing from the rectum to the ileum. Upper gastrointestinal endoscopy showed a slightly rough gastric mucosal surface, and chicken-skin like mucosa was observed in the second portion of the duodenum. Small-to-medium size lymphoma cells were seen histologically from the tonsilla to the rectum. The lymphoma cells were immunohistochemically positive for CD5, CD20, CD79a, and cyclin D1. Polymerase chain reaction analysis revealed a chromosomal translocation t(11;14)(q13;q32) in the bcl-1 gene. We diagnosed this as a case of MCL from these findings. For treatment, the patient received a total of ten courses of combination chemotherapy consisting of cyclophosphamide (1000 mg), doxorubicin (70 mg), vincristine (2 mg) and prednisolone (50 mg) (CHOP), which led to a partial remission. However, 2.5 years later, massive infiltrations of the lymphoma cells were found in the colon and stomach. As the infiltrating lymphoma cells expressed CD20 molecules on their surfaces, the patient was treated with a chimeric anti-CD20 monoclohal antibody, rituximab, which showed significant efficacy, and a second partial remission was achieved.

Analysis of K-ras codon 12 mutation in flat and nodular variants of serrated adenoma in the colon.

PURPOSE: The developmental process of serrated adenomas is obscure, and the importance of genetic alterations has not been elucidated clearly. The possibility that the developmental process and genetic alterations of serrated adenomas could differ from those of ordinary tubular adenomas was explored in this work. METHODS: Serrated adenomas were obtained by endoscopic resection (n = 57) and divided into two groups: flat (n = 10) and nodular (n = 47). Mutation of the K-ras gene was analyzed by enriched polymerase chain reaction-enzyme-linked mini-sequence assay, which can detect not only the presence of a mutation but also the mutation type of K-ras codon 12 with high sensitivity. Methylation-specific polymerase chain reaction was performed with specific primers for the DNA repair gene O6-methylguanine-DNA methyltransferase. RESULTS: Serrated adenomas located in the rectum were more likely to have a K-ras mutation (9/12, 75 percent), whereas serrated adenomas of the flat type were less likely to have one (1/10, 10 percent). Furthermore, nodular serrated adenomas that occurred in the rectum possessed a high frequency of K-ras gene codon 12 point mutation (8/10, 80 percent) despite an overall frequency of 46.8 percent (22/47). A mutation of the K-ras codon 12 gene was detected in 23 (40.4 percent) of 57 serrated adenomas. Three types of point mutations of codon 12 were detected, with the mutation of GAT being observed most frequently. CONCLUSIONS: This study shows that development of nodular serrated adenomas may depend on the mutation of the K-ras codon 12 gene, whereas development of flat serrated adenomas may not. Additionally, serrated adenomas that occur in the rectum are closely related to the mutation of the K-ras codon 12 gene. K-ras mutations in serrated adenomas may be unaffected by the epigenetic silencing of O6-methylguanine-DNA methyltransferase by promoter hypermethylation.

Pit pattern and three-dimensional configuration of isolated crypts from the patients with colorectal neoplasm.

BACKGROUND: This study examined the usefulness of magnifying videoscopic pit-pattern diagnosis in the differential diagnosis of colonic neoplasms. The relationship between pit patterns and the three-dimensional configuration of the neoplastic gland was evaluated for its contribution toward an understanding of pit patterns. METHODS: A total of 3005 colorectal lesions were examined endoscopically and histopathologically. Pit patterns were classified into six types. All materials used for crypt isolation were derived from segments of 21 colorectal lesions and one normal colonic mucosa. For the crypt isolation, the HCl-digestion method was used. RESULTS: The magnifying videoscopic diagnosis was comparable with the histological diagnosis in the 3005 colorectal lesions. Isolated crypts with the type-I pit pattern resembled a test-tube; the type-II pit pattern was also tubular, but had observed fissures at the bottom; the type-III l pit pattern was a reversed triangle or tongue-like in shape; and the type-III s pit pattern was columnar and either tapered off or meandered. Isolated crypts with the type-IV b pit pattern appeared as long reversed triangles with protuberances, and the type-IV v pit pattern was flat with slender tubules or finger-like processes. The isolated crypts with the type-V pit pattern were complicated and indistinct in shape. CONCLUSIONS: Evaluation of the three-dimensional configuration revealed that when the pit patterns, of each isolated crypt differed, their three-dimensional configurations also differed. Recognition of the differences in the three-dimensional configuration should contribute toward both an understanding of pit-pattern diagnosis and the further development of the endoscopic diagnosis of various colorectal lesions.