Lynch Syndrome (Hereditary Nonpolyposis Colorectal Cancer Syndrome) Joel K. Greenson, MD Key Facts Terminology Germline defect in 1 or more DNA mismatch repair enzymes, which leads to neoplasia Autosomal dominant…
Familial Cancer Syndromes in Colorectal Carcinoma Joel K. Greenson, MD TERMINOLOGY Abbreviations Familial adenomatous polyposis (FAP) Adenomatous polyposis gene (APC) Hereditary nonpolyposis colorectal cancer (HNPCC) Definitions Familial cancer syndromes =…
Sessile Serrated Adenoma Alexandros D. Polydorides, MD, PhD Key Facts Terminology Serrated polyps: Saw-toothed epithelium (infolding) HP, TSA, SSA/P, mixed adenoma-serrated polyps Etiology/Pathogenesis Inhibition of apoptosis/exfoliation of surface mucosa “Serrated…
Mixed Adenoma-Serrated Polyp Alexandros D. Polydorides, MD, PhD Key Facts Etiology/Pathogenesis Serrated path: HP → SSA/P → MASP → TSA → cancer? MSI, CIMP (MGMT, hMLH1), BRAF mutations Clinical Issues…
Ganglioneuroma Elizabeth A. Montgomery, MD Key Facts Terminology Neoplasm composed of mixture in variable proportions of spindled schwannian cells and ganglion cells Syndromic lesions associated with MEN2b, NF1, and FAP…
Benign Fibroblastic Polyp/Perineurioma Elizabeth A. Montgomery, MD Key Facts Terminology Colonic mucosal proliferation of monomorphic spindle cells leading to separation, entrapment, and disorganization of colonic crypts Morphologically identical lesions variably…
Entamoeba Histolytica Laura W. Lamps, MD Key Facts Etiology/Pathogenesis Affects approximately 10% of world population Clinical Issues Nondysenteric infection: Milder symptoms Dysenteric or invasive infection: Sudden, severe diarrhea, abdominal cramps…
Spirochetosis Laura W. Lamps, MD Key Facts Clinical Issues Most commonly affects colonic mucosa in men with HIV/AIDS Most common symptom is diarrhea, but unclear whether spirochetosis actually causes symptoms…
Clostridium Difficile Laura W. Lamps, MD Key Facts Terminology Infection by Clostridium difficile, most common nosocomial GI infection Causes colitis, most often pseudomembranous colitis Etiology/Pathogenesis Usually associated with recent antibiotic…
Enterohemorrhagic E. coli Infections Laura W. Lamps, MD Key Facts Terminology Most common strain of EHEC is O157:H7, but there are others Etiology/Pathogenesis Infection usually acquired from contaminated food Clinical…
