Incidental finding of diffuse cavernous rectal haemangiomatosis during bowel cancer screening.

BACKGROUND: This case seeks to highlight to endoscopists a rare benign disorder that may be encountered during endoscopy. Clinicians may be tempted to biopsy, which could lead to a catastrophic gastrointestinal haemorrhage. CASE PRESENTATION: A 66-year-old asymptomatic Caucasian male was referred for colonoscopy with a positive faecal occult blood test as part of the UK national bowel cancer screening programme. Relevant past medical history included atrial fibrillation for which he took Dabigatran. He had a normal haemoglobin, mean cell volume, platelet and clotting function. During colonoscopy, an unusual vascular pattern encompassing the entire rectum extending to the rectosigmoid junction was noted at intubation. The lesion demonstrated confluent circumferential purple discolouration indicating venous blood supply, with heaping up of the mucosa involving the entire rectum and rectosigmoid junction. There was no corresponding history of venothromboembolic disease or liver disease. The patient proceeded to have computed tomography (CT) which revealed a considerably thickened rectosigmoid wall with multiple small rounded punctate calcifications within it, and no other visceral involvement. Subsequent magnetic resonance (MR) scan of the pelvis demonstrated extensive diffuse thickening of the rectum and lower sigmoid with intermediate to high T2 signal, and an internal architecture of multiple 'grapelike' lobulations. CONCLUSION: The findings were consistent with diffuse cavernous haemangiomatosis of the rectum (DCHR), an extremely rare benign submucosal vascular intestinal tumour originating from the dentate line. Misdiagnosis of DCHR is common and the macroscopic appearance of DCHR can mimic varices, haemorrhoids, polyps or proctitis. MR imaging is the gold standard for diagnosis. Common presentation is with haematochezia due to mucosal wall erosion. The treatment of choice for symptomatic DCHR is pull-through transection and colo-anal anastomosis. This case seeks to highlight a rare disorder that can be encountered incidentally during lower GI endoscopy. Injudicious biopsy is potentially catastrophic. In a patient who endoscopically has evidence of a DCHR, we advocate MR pelvis assessment to clarify the nature of the lesion to guide future management if required. The patient discussed remains well, asymptomatic, with no evidence of iron deficiency anaemia.

Altered colonic mucosal availability of n-3 and n-6 polyunsaturated fatty acids in ulcerative colitis and the relationship to disease activity.

BACKGROUND AND AIMS: The polyunsaturated fatty acids (PUFA) arachidonic acid (AA, n-6) and eicosapentaenoic acid (EPA, n-3) are precursors of eicosanoids and other lipid mediators which have critical roles in inflammation. The mediators formed from the different PUFA have different potencies. We hypothesised that metabolic changes associated with colonic mucosal inflammation would modify the bioavailability of the eicosanoid precursors AA and EPA. METHODS: Colonic mucosa biopsies were obtained from patients with ulcerative colitis and from matched controls. Inflammation was graded endoscopically and histologically. Esterified and non-esterified fatty acids were determined within the biopsies using gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry, respectively. RESULTS: Biopsy samples were collected from 69 UC patients (54 providing both inflamed and non-inflamed mucosa) and 69 controls. Inflamed mucosa had higher AA (p<0.001) and lower EPA (p<0.010) contents and a higher AA:EPA ratio (p<0.001). Inflamed mucosa also had higher docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) and lower linoleic acid (LA) and α-linolenic acid (α-LNA) contents (all p<0.001), compared to non-inflamed and controls. There were significant correlations between severity of inflammation and contents of AA, DPA and DHA (positive correlations) and of LA, α-LNA and EPA (negative correlations). CONCLUSIONS: Higher AA, AA:EPA ratio, DPA and DHA and lower LA, α-LNA and EPA are seen in inflamed mucosa in UC and correlate with severity of inflammation. This suggests an alteration in fatty acid metabolism in the inflamed gut mucosa, which may offer novel targets for intervention and should be considered if nutritional strategies are used.

Altered colonic mucosal Polyunsaturated Fatty Acid (PUFA) derived lipid mediators in ulcerative colitis: new insight into relationship with disease activity and pathophysiology.

OBJECTIVES: Ulcerative colitis (UC) is a relapsing inflammatory disorder of unconfirmed aetiology, variable severity and clinical course, characterised by progressive histological inflammation and with elevation of eicosanoids which have a known pathophysiological role in inflammation. Therapeutic interventions targetting eicosanoids (5-aminosalicylates (ASA)) are effective first line and adjunctive treatments in mild-moderate UC for achieving and sustaining clinical remission. However, the variable clinical response to 5-ASA and frequent deterioration in response to cyclo-oxygenase (COX) inhibitors, has prompted an in depth simultaneous evaluation of multiple lipid mediators (including eicosanoids) within the inflammatory milieu in UC. We hypothesised that severity of inflammation is associated with alteration of lipid mediators, in relapsing UC. DESIGN: Study was case-control design. Mucosal lipid mediators were determined by LC-MS/MS lipidomics analysis on mucosal biopsies taken from patients attending outpatients with relapsing UC. Univariate and multivariate statistical analyses were used to investigate the association of mucosal lipid mediators, with the disease state and severity graded histologically. RESULTS: Levels of PGE2, PGD2, TXB2, 5-HETE, 11-HETE, 12-HETE and 15-HETE are significantly elevated in inflamed mucosa and correlate with severity of inflammation, determined using validated histological scoring systems. CONCLUSIONS: Our approach of capturing inflammatory mediator signature at different stages of UC by combining comprehensive lipidomics analysis and computational modelling could be used to classify and predict mild-moderate inflammation; however, predictive index is diminished in severe inflammation. This new technical approach could be developed to tailor drug treatments to patients with active UC, based on the mucosal lipid mediator profile.

Cytokine mucosal expression in ulcerative colitis, the relationship between cytokine release and disease activity.

BACKGROUND: Ulcerative colitis (UC) is an inflammatory bowel disease with conflicting evidence from studies on the roles of TNFα, IL-8, TGFß and other cytokines and characterised by neutrophil infiltration and tissue destruction. AIM: To compare cytokine profiles of inflamed and non-inflamed mucosa in patients with distal UC, and matched controls. METHODS: Patients were prospectively recruited, mucosal biopsies at flexible sigmoidoscopy (FS) were taken from UC patients within macroscopically inflamed and non-inflamed proximal mucosa, and from age-sex matched controls undergoing FS. Endoscopic and histological inflammation was graded. Quantitative cytokine analysis for IL-4, TNFα, IL-17A, IL-8, IL-10, TGFß and IFNγ was carried out on tissue homogenates. Statistical comparison was by Wilcoxon signed rank pair analysis, Mann-Whitney U test and Spearman's correlation. RESULTS: 69 active UC patients (54 paired non-inflamed/inflamed mucosa) and 69 controls were compared. In inflamed mucosa, elevation in IL-8 and reduction in TGFß was measured compared with non-inflamed mucosa (p<0.001; p<0.02) and control mucosa (p<0.001; p<0.001); IL-8 was positively correlated (rs=0.481, p<0.01) and TGFß inversely correlated (rs=0.462; p<0.01) with grade of inflammation. TNFα concentration was not significantly different. Comparisons of inflamed with non-inflamed mucosa also demonstrate significant reduction in concentration of IFNγ (p<0.001), IL-4 (p<0.005) and IL-17A (p<0.002). CONCLUSION: Our findings suggest that IL-8 is elevated and TGFß is reduced in distal colitis. Lower concentration of IFNγ, IL-4 and IL-17A were also noted. TNFα levels were unchanged. These findings suggest that the inflammatory response in UC may predominantly involve IL-8 mediated neutrophil infiltration and failure of TGFß mediated tissue healing.