Faculty Bibliography

Article Title: Morbidity and Mortality Following Surgery for Non-Malignant Colorectal Polyps: A 10-Year Nationwide Analysis.

Article Title: Effects of the DASH Diet and Sodium Intake on Bloating: Results from the DASH-Sodium Trial.

To receive CME/MOC credit for this activity, please go to: http://acgjournalcme.gi.org/Article Title: Influence of Dietary Restriction on Irritable Bowel Syndrome.

BACKGROUND: Colorectal cancer is a heterogeneous disease arising from at least two precursors-the conventional adenoma (CA) and the serrated polyp. We and others have previously shown a relationship between the human gut microbiota and colorectal cancer; however, its relationship to the different early precursors of colorectal cancer is understudied. We tested, for the first time, the relationship of the gut microbiota to specific colorectal polyp types. RESULTS: Gut microbiota were assessed in 540 colonoscopy-screened adults by 16S rRNA gene sequencing of stool samples. Participants were categorized as CA cases (n = 144), serrated polyp cases (n = 73), or polyp-free controls (n = 323). CA cases were further classified as proximal (n = 87) or distal (n = 55) and as non-advanced (n = 121) or advanced (n = 22). Serrated polyp cases were further classified as hyperplastic polyp (HP; n = 40) or sessile serrated adenoma (SSA; n = 33). We compared gut microbiota diversity, overall composition, and normalized taxon abundance among these groups. CA cases had lower species richness in stool than controls (p = 0.03); in particular, this association was strongest for advanced CA cases (p = 0.004). In relation to overall microbiota composition, only distal or advanced CA cases differed significantly from controls (p = 0.02 and p = 0.002). In taxon-based analysis, stool of CA cases was depleted in a network of Clostridia operational taxonomic units from families Ruminococcaceae, Clostridiaceae, and Lachnospiraceae, and enriched in the classes Bacilli and Gammaproteobacteria, order Enterobacteriales, and genera Actinomyces and Streptococcus (all q < 0.10). SSA and HP cases did not differ in diversity or composition from controls, though sample size for these groups was small. Few taxa were differentially abundant between HP cases or SSA cases and controls; among them, class Erysipelotrichi was depleted in SSA cases. CONCLUSIONS: Our results indicate that gut microbes may play a role in the early stages of colorectal carcinogenesis through the development of CAs. Findings may have implications for developing colorectal cancer prevention therapies targeting early microbial drivers of colorectal carcinogenesis.

Chylous ascites is an entity not previously reported in association with AIDS. A 43-yr-old male with previous diagnosis of AIDS developed chylous ascites. Septic complications lead to his death. At autopsy, Kaposi's sarcoma (KS) lesions were present on the skin, in the omentum, mesentery, and small and large bowel mucosa. A histological section of the cisterna chyli showed involvement and obstruction by KS. This represents a unique case in which the mechanism leading to the formation of chylous ascites by KS was demonstrated by the autopsy findings in an HIV-positive patient

Acute renal failure is rarely the presenting manifestation of non-Hodgkin's lymphoma. Of the reported cases of renal insufficiency secondary to diffuse renal infiltration with lymphoma, few have presented with acute renal failure. We present a patient with acute renal failure secondary to diffuse bilateral renal infiltration by a B-cell non-Hodgkin's lymphoma. The findings of an elevated serum lactate dehydrogenase (LDH), lymphopenia, and homogenous bilateral renal enlargement on computed tomographic (CT) imaging were important in suggesting the diagnosis of primary renal lymphoma. Renal biopsy with immunohistochemical and ultrastructural analysis was instrumental in confirming this diagnosis

Spontaneous intramural hematoma of the esophagus (SIHE) is a rare condition usually affecting middle-aged or elderly women. It presents as acute substernal or epigastric pain, typically accompanied by dysphagia or hematemesis. SIHE is not usually associated with vomiting, and is therefore clearly distinguished from emetogenic esophageal disorders, such as the Mallory-Weiss lesion and the Boerhaave syndrome. The diagnosis has traditionally been made by barium esophagram. Therapy is conservative; a favorable prognosis is the rule. The pathogenesis is in dispute. We present a case of SIHE without a discernible mucosal breach, suggesting a primary intramural bleed as the initiating event. We document the utility of computed tomographic scan and magnetic resonance imaging in the diagnosis of SIHE