SM_162b: Pathology of Colonic Disorders Flashcards
Colon is the part of the mucosa that extends from the ____ to ____
Colon is the part of the mucosa that extends from the cecum to rectum
Four layers of colon are ____, ____, ____, and ____
Four layers of colon are the mucosa, submucosa, muscularis propria, and adventitia / serosa
Describe staging carcinomas based on histology of colon
Staging carcinomas based on histology of colon
- Mucosa: Tis (in situ)
- Submucosa: T1
- Muscularis propria: T2
- Serosa: T3
Colonic mucosa consists of ____, ____, and ____ and functions to ____ and ____
Colonic mucosa consists of epithelium, lamina propria, and muscularis mucosae and functions to absorb water and allow passage of stool protection
- Epithelium: absorptive cells, goblet cells, Paneth cells (only in right colon), endocrine cells
- Lamina propria: plasma cells, eosinophils, lymphocytes
- Muscularis mucosae: thin smooth layer created by gentle agitation
These are ____ and ____
These are endocrine cells and Paneth cells
Colonic submucosa consists of ____ and ____
Colonic submucosa consists of loose connective tissue and ganglion cells (Meissner’s plexus)
- Loose connective tissue: fibroblasts, lymphatics, blood vessels
____ is the main layer of the GI tract and creates peristalsis
Muscularis propria is the main layer of the GI tract and creates peristalsis
- Inner circular smooth muscle layer
- Outer longitudinal smooth muscle layer
- Ganglion cells (Auerbach’s plexus)
Colitis is inflammation of the colon and presents with ____, ____, ____, ____, and ____
Colitis is inflammation of the colon and presents with abdominal pain, diarrhea, urgency, hemorrhage, and incontinence
Infectious colitis is most commonly ____ and involves ____ and ____
Infectious colitis is most commonly active inflammation and most commonly involves cryptitis and crypt abscesses
- Cryptitis: neutrophils in the epithelium
- Crypt abscesses: neutrophils in the crypt lumina
- Pattern of inflammation depends the causative agent
Cryptitis is ____
Cryptitis is neutrophils in the epithelium
Crypt abscesses are ____
Crypt abscesses are neutrophils in the crypt lumina
Pseudomembranous colitis involves a pseudomembrane composed of ____, ____, and ____
Pseudomembranous colitis involves a pseudomembrane composed of necrotic epithelial cells, acute inflammatory cells, and fibrinous material
- Causes: Clostridioides difficile, ischemic colitis, IBD
Describe Clostridium difficile membranous colitis pathophysiology
Clostridium difficile membranous colitis pathophysiology
- Administration of antibiotic
- Overgrowth of C. difficile
- Production of toxins
- Epithelial / endothelial damage and inflammation
Presents with diarrhea, abdominal pain, nausea / vomiting, fever
Clostridium difficile pseudomembranous colitis is diagnosed via ____
Clostridium difficile pseudomembranous colitis is diagnosed via testing for C. difficile toxin in the stool
(endoscopy also used)
Discrete, raised creamy yellow plaques of 1-5 mm on the colon indicates ___
Discrete, raised creamy yellow plaques of 1-5 mm on the colon indicates pseudomembranous colitis
(C. difficile)
This is a ____ that occurs in ____
This is a pseudomembrane that occurs in pseudomembranous colitis
Microscopic colitis is ____ with two entities: ____ and ____
Microscopic colitis is chronic non-bloody diarrhea with two entities: lymphocytic colitis and collagenous colitis
- Radiologic and endoscopic studies are normal
- Pathology can identify the process
IBD is ____ that consists of ____ and ____ and presents as ____
IBD is chronic relapsing inflammation of all or portions of the GI tract that consists of Crohn’s Disease and Ulcerative Colitis and presents as subtle abdominal pain to bloody diarrhea
Ulcerative colitis is primarily an ____ and begins in the ____ and progresses ____
Ulcerative colitis is primarily an inflammatory condition of the mucosa and begins in the rectum and progresses proximally
(may involve the entire colon)
Ulcerative colitis involves clinical features of ____, ____, and ____
Ulcerative colitis involves clinical features of sudden bloody diarrhea, vague abdominal pain, and acute toxic megacolon
- Acute toxic megacolon: pancolitis -> dilatation -> no peristalsis -> rapid deterioration
Crohn’s disease is ____, that occurs most commonly in the ____, and involves ____
Crohn’s disease is chronic discontinuous inflammation, that occurs most commonly in the terminal ileum and / or colon, and involves all layers of the GI tract (transmural inflammation)
Crohn’s disease clinical features are ____, ____, ____, and ____
Crohn’s disease clinical features are diarrhea (chronic, nocturnal, occassionally bloody), crampy abdominal pain, fever / malnutrition / fatigue / anemia, weight loss
Ulcerative colitis involves inflammation of ____, while Crohn’s Disease involves ____ inflammation
Ulcerative colitis involves inflammation of mucosa, while Crohn’s Disease involves transmural inflammation
Ulcerative colitis histologic findings include ____, ____, and ____
Ulcerative colitis histologic findings include chronic inflammation, active inflammation, and limited to mucosa
- Chronic inflammation: too many lymphocytes and plasma cells in lamina propria, distorted crypt architecture
- Active inflammation: cryptitis (neutrophils in epithelium) and crypt abscess (neutrophils in the lumen of the crypt)
Crohn’s disease histologic findings include ____, ____, ____, and ____
Crohn’s disease histologic findings include chronic inflammation, active inflammation, transmural inflammation, and noncaseating granulomas
- Chronic inflammation: too many lymphocytes and plasma cells in lamina propria, distorted crypt architecture
- Active inflammation (acute): cryptitis (neutrophils in epithelium)
____ has gross pathology of heal stricture, serpiginous ulcers, and cobble stone due to patchy involvement
Crohn’s Disease has gross pathology of heal stricture, serpiginous ulcers, and cobble stone due to patchy involvement
Describe macroscopic differences between ulcerative colitis and Crohn’s Disease
Macroscopic differences between ulcerative colitis and Crohn’s Disease
- Crohn’s Disease: discontinuous, terminal ileum involved
- Ulcerative colitis: continuous, rectum always involved
Describe microscopic differences between ulcerative colitis and Crohn’s Disease
Microscopic differences between ulcerative colitis and Crohn’s Disease
- Ulcerative colitis: mucosal inflammation, crypt abscess common
- Crohn’s disease: transmural inflammation, granulomas
___ is a common systemic complication of ulcerative colitis
Primary sclerosing colangitis is a common systemic complication of ulcerative colitis
- Increased risk of biliary cancer
- Also toxic megacolon, hemorrhage, inflammatory polyposis, and cancer
Ulcerative colitis increases risk of ____ particularly with onset in childhood, pancolitis, and duration of disease > 10 years
Ulcerative colitis increases risk of colon cancer particularly with onset in childhood, pancolitis, and duration of disease > 10 years
- Invasive cancer preceded by the development of dysplasia: low grade dysplasia, high grade dysplasia, indefinite for dysplasia
____ are abnormal growths of tissue projecting from a mucous membrane and can be ____ or ____
Polyps are abnormal growths of tissue projecting from a mucous membrane and can be sessile or pedunculated (with stalk)
- Non-neoplastic: hyperplastic, inflammatory, hamartomatous
- Neoplastic: tubular adenoma, villous adenoma, tubulovillous adenoma, sessile serated adenoma
Hyperplastic polyps ____, ____, ____, and ____
Hyperplastic polyps occur often in the left colon, are small (< 5 mm), include mature goblet cells and absorptive cells, and include a serration
- Serration (star shaped): typically restricted to approximately the upper third of crypts
Inflammatory polyp is composed of ____
Inflammatory polyp is composed of a non-neoplastic mixture of epithelial, stromal, and inflammatory cells
- Related to IBD, prolapse type inflammatory polyps, and solitary rectal ulcer syndrome
Describe pathophysiology of solitary rectal ulcer syndrome
Solitary rectal ulcer syndrome pathophysiology
- Impaired relaxation of anorectal sphincter
- Recurrent abrasion and ulceration of the mucosa
- Inflammatory polyp
- Entrapment of polyp in fecal stream
- Mucosal prolapse
Solitary rectal ulcer syndrome presents with the triad of ____, ____, and ____
Solitary rectal ulcer syndrome presents with the triad of rectal bleeding, mucus discharge, and an inflammatory lesion / polyp
Hamartamous polyps are ____ composed of ____ often with ____
Hamartamous polyps are benign tumor-like nodules composed of an overgrowth of tissue present in the area often with one element predominating
- Sporadic: juvenile polyp, Peutz-Jeghers polyp
- Components of various genetic / acquired syndromes
Juvenile polyps occur often ____, are most often located in ____ and present with ____, and can be ____ or ____
Juvenile polyps occur often in children < 5 years, are most often located in rectum and present with bleeding, and can be sporadic or syndromic juvenile polyposis
- Syndromic juvenile polyposis can undergo malignant transformation -> increased risk of colonic adenocarcinoma
Syndromic juvenile polyposis can undergo ____ transformation leading to an increased risk of ____
Syndromic juvenile polyposis can undergo malignant transformation leading to an increased risk of colonic adenocarcinoma
Peutz-Jeghers syndrome is caused by ____, results in ____, and increases risk of ____
Peutz-Jeghers syndrome is caused by STK11 gene mutation, results in GI hamartomatous polyps and mucocutaneous hyperpigmentation, and increases risk of malignancies
- Malignancies: breast and GI (pancreas)
- Complex architecture w/ smooth muscle bundles cutting through lamina propria
Juvenile polyposis involves mutation in ____, while Peutz-Jeghers syndrome involves mutations in ____
Juvenile polyposis involves mutation in SMAD4, while Peutz-Jeghers syndrome involves mutations in STK11
Neoplastic polyps of the colon are precursors for ____
Neoplastic polyps of the colon are precursors for colorectal carcinoma
- Classification: tubular adenoma, villous adenoma, tubulovillous adenoma, sessile serrated adenoma
Tubular adenomas have ____, are mostly ____ but may ____ if large, and have increased incidence with ____
Tubular adenomas have low grade dysplasia, are mostly silent but may bleed if large, and have increased incidence with age
Villous adenoma is characterized by ____, most often located in the ____, and are ____ and ____
Villous adenoma is characterized by epithelial proliferation arranged as slender villi, most often located in the rectum, and are often larger and sessile
Sessile serrated adenomas often occur in the ____, have ____ potential, and ____ typical cytologic features of dysplasia
Sessile serrated adenomas often occur in the right colon, have malignant potential, and lack typical cytologic features of dysplasia
- Overlap histologically with hyperplastic polyps
Neoplastic polyps may undergo malignant transformation (adenoma-carcinoma sequence), particularly if ____
Neoplastic polyps may undergo malignant transformation (adenoma-carcinoma sequence), particularly if large
Size matters!
Risk factors for colon cancer include ____, ____, and ____
Risk factors for colon cancer include smoking, dietary factors (high fat diet, low fiber diet), and obesity
Describe carcinoma of the colon and rectum
Carcinoma of the colon and rectum
- Distribution: rectosigmoid > ascending > descending
- Ascending colon -> iron deficiency anemia, weight loss
- Descending colon -> colicky pain, partial obstruction, hematochezia
- Pathology: gross (ulcerating, annular, polypoid), microscopic (adenocarcinomas_
Familial adenomatous polyposis results from ____ and causes ____
Familial adenomatous polyposis results from germline mutation of APC gene and causes colorectal adenocarcinoma often by age 30
- APC: tumor suppressor gene, on chromosome 5
- Autosomal dominant
- Multiple tubular adenomas (> 100)
Extra-intestinal manifestations: congenital hypertrophy of retinal pigmented epithelium at birth -> early screening - Treatment: colectomy
*
Hereditary nonpolyposis colorectal cancer (Lynch syndrome) has ____ inheritence, results from ____, and involves ____
Hereditary nonpolyposis colorectal cancer (Lynch syndrome) has autosomal dominant inheritence, results from mutations in genes encoding proteins responsible for detection / repair of errors during DNA replication, and involves familial clustering of cancers
- DNA instability (microsatellite instability)
Hereditary nonpolyposis colorectal cancer (Lynch syndrome) is often ____
Hereditary nonpolyposis colorectal cancer (Lynch syndrome) is often right colon cancer
- Younger age than sporadic
MLH1, MSH2, MSH6, and PMS2 mutations can result in ____
MLH1, MSH2, MSH6, and PMS2 mutations can result in hereditary nonpolyposis colorectal cancer (Lynch syndrome)
- DNA instability (microsatellite instability)
Colonic adenocarcinoma may involve ____
Colonic adenocarcinoma may involve infiltrative carcinoma invading the submucosa
Prognostic factors in colorectal carcinoma are ____, ____, and ____
Prognostic factors in colorectal carcinoma are depth of pentration (stage), metastasis to lymph nodes or other organs (liver), and type of differentiation
- Poorly differentiated and mucinous -> poor prognosis
- Prevention / screening via colonoscopy and removal of precursor
