RESUMO
Clear cell adenocarcinomas of the colon are defined as a subtype of colorectal adenocarcinoma with clear cell morphology. A 65-year old man was admitted to a Gastroenterology Department for diagnostic evaluation of a tumor in the sigmoid colon found on CT. There, the patient developed complete bowel obstruction and was operated urgently, where intraoperatively, a large tumor in the sigmoid fixated to the lateral abdominal wall was revealed. A subtotal colectomy was performed. Histopathological analysis of the surgical specimen was conducted. The immunohistochemistry staining was positive for CEA, CDX2, and CD20 and negative for CK7, CD10, MUC2, AFP, and PAS staining. Mismatch repair protein testing was negative. The pathological diagnosis was mucinous carcinoma with a clear cell component which bears an extremely low incidence that has been scarcely reported in literature. This stresses the need for more case reports like ours to be published.
RESUMO
AIMS: To compare ranitidine bismuth citrate with omeprazole as to their efficacy to eradicate H. pylori in two different treatment schedules both consisting of a combination of either of above with two antibiotics for 1 week, and to relate these treatment results to primary antibiotic resistance. METHODS: 256 H. pylori positive patients with non-ulcer dyspepsia were randomised to one of the following four treatment groups: omeprazole 20 mg + clarithromycin 500 mg + amoxycillin 1000 mg (OCA); ranitidine bismuth citrate 400 mg + clarithromycin 500 mg + amoxycillin 1000 mg (RBCCA); omeprazole 20 mg + clarithromycin 500 mg + metronidazole 500 mg (OCM); ranitidine bismuth citrate 400 mg + clarithromycin 500 mg + metronidazole 500 mg (RBCCM). All drugs were given twice daily for one week. The patients were assessed for prevalence of H. pylori by CLO test, histology and culture on gastric biopsy samples obtained during upper gastrointestinal endoscopy before randomisation and 4-6 weeks after completion of therapy. Bacterial sensitivity to clarithromycin, metronidazole and amoxycillin was determined by E-test. RESULTS: On per-protocol analysis, overall eradication rates were 96% for RBCCA vs. 85% for OCA (p = 0.03), and 95% for RBCCM vs. 79% for OCM (p = 0.01). Amongst the 196 patients (77% of the entire study group) in whom antibiotic sensitivity testing was technically feasible, primary resistance was found in 8% for clarithromycin, in 33% for metronidazole, and in 0% for amoxycillin. Eradication of clarithromycin sensitive/resistant strains was 89%/40% for OCA (p = 0.0042) and 98%/80% for RBCCA (p = 0.0428). When strains were sensitive to both antibiotics, cure rates with OCM/RBCCM were 87%/96% respectively (p = 0.39), for strains resistant to clarithromycin only, eradication was achieved in 82% with OCM vs. 94% with RBCCM (p = 0.2), and in the case of metronidazole resistance in 85% with OCM vs. 94% with RBCCM (p = 0.09). CONCLUSIONS: Ranitidine bismuth citrate in combination with clarithromycin and either metronidazole or amoxycillin produced higher eradication rates than omeprazole co-administered with the same antibiotics. This appeared especially prominent in the subgroups with clarithromycin resistance without, however, reaching statistical significance. Efficacy of neither eradication regimen was influenced by metronidazole sensitivity to a significant degree.
