10.3 - Pathological Conditions of the ______ Flashcards

Question

Causes of Colorectal Cancer

Answer 1

- malignancy arising in large intestine, colon, or rectum 1) Genetic Factors a) Familial Adenomatous Polyposis (FAP) - APC gene mutation - Numerous polyps in the colon = progresses to cancer if untreated b) Hereditary Non-Polyposis Colorectal Cancer (HNPCC) or Lynch Syndrome - Mutations in DNA mismatch repair (MMR) genes ↑ cancer risk by disrupting DNA repair = accumulation of genetic mutations 2) Environmental & Lifestyle Factors - Diets high in red and processed meats, low fiber, sedentary lifestyles, smoking, & excessive alcohol intake = ↑ colon cancer risk 3) Inflammatory Bowel Disease (IBD) - UC or CD = chronic inflammation & ↑ risk of colon cancer due to DNA damage & accelerated cell turnover

Answer 2

- typically follows progression from benign polpys to invasive adenocaorncomoa through genetic mutations 1) Adenoma-Carcinoma Sequence - Begins with formation of a small adenomatous polyp [mutations in APC gene, as additional mutations accumulate (KRAS & TP53 genes) = polyp grows larger & undergoes dysplasia = carcinoma 2) Microsatellite Instability (MSI) - common in Lynch syndrome = mutations in DNA mismatch repair (MMR) genes = microsatellite instability = accelerated mutation rates = hallmark of a subset of colon cancers 3) CpG Island Methylator Phenotype (CIMP) - Sporadic cases = hypermethylation of specific DNA regions = gene silencing = uncontrolled cell proliferation

Answer 3

1) Polyp Formation - Benign adenomatous polyps develop in the mucosal lining - Polyps can be tubular, villous, or tubulovillous - Villous polyps carry the highest cancer risk 2) Dysplasia and Invasive Cancer - Dysplastic changes within polyps = adenocarcinoma (cancerous cells invade mucosal, submucosal, & muscular layers of colon wall) 3) Metastasis - Invasion of blood vessels & lymph nodes = METS to liver, lungs, & peritoneum (cells enter circulation through lymph or blood) - Structural changes at metastatic sites reflect primary tumor’s histological pattern

Answer 4

1) Adenocarcinoma - Most common (> 90% of cases) - Originates in glandular cells - Progresses from polyps, various subtypes 2) Mucinous Adenocarcinoma - Mucus-producing cancer cells - associated with poor prognosis & high METS 3) Signet Ring Cell Carcinoma - Rare & highly aggressive - Cells with prominent intracellular mucin - Presents at an advanced stage 4) Small Cell Carcinoma - Rare & highly aggressive - Neuroendocrine cancer - Distinct treatment approach

Answer 5

S&S - Changes in bowel habits (diarrhea or constipation) - rectal bleeding - unexplained weight loss - abdominal pain - anemia - Right-sided tumors (ascending colon) present with anemia & weight loss -ascending colon has large lumen (does not cause obstruction unless very large, instead bleed overtime) - Left-sided tumors (descending and sigmoid colon) cause obstructive symptoms Staging Colon cancer staging uses the TNM (Tumor, Node, Metastasis) - Stage I: Limited to colon wall - Stage II: Extends beyond muscular layer, no lymph node involvement - Stage III: Involves regional lymph nodes - Stage IV: Distant metastasis (e.g., liver or lungs bc highly vasculated) Diagnosis - Colonoscopy with biopsy - resection surgery (removal of bowel)

Answer 6

- occurs when organ tissue protrudes through weak spot in surrounding muscle or tissue Causes - Increased intra-abdominal pressure (e.g., coughing, constipation - heavy lifting, or obesity) weakness in the abdominal wall [congenital or acquired (e.g., surgical scars or aging)], Risk Factors - family history/genetics - Increasing age - male gender (anatomy of inguinal canal) - smoking (impairs tissue repair & collagen synthesis = weakens connective tissue) - previous surgery or injury (scar tissue)

Answer 7

- develop due to imbalance bw increased intra-abdominal pressure and resistance of the abdominal wall structure resulting from: - Weak connective tissue (genetic or acquired) - Failure of embryologic closure (e.g., incomplete closure of processus vaginalis in inguinal region) - Chronic straining or trauma (weakens abdominal muscles or fascia) - Inguinal hernias occur through the inguinal canal, which has structures such as the spermatic cord (males) or round ligament (females), can be - Indirect = congenital - Direct = acquired

Answer 8

1) Protrusion of viscera Small intestine, omentum, or bladder 2) Weakness of muscle and fascial layers - Sites of weakness (e.g., inguinal canal, umbilicus, or surgical scars) 3) Hernial sac - Peritoneum & may contain bowel or other abdominal contents (meaning more severe bc has abdominal contents) 4) Inguinal hernias -a) Indirect inguinal hernia - Protrudes through deep inguinal ring, follows path of inguinal canal, reaching scrotum (males) b) Direct inguinal hernia - Protrudes directly through posterior wall of inguinal canal due to weakness in transversalis fascia 5) Abdominal hernias a) Umbilical hernia - Protrudes through umbilical ring b) Incisional hernia - Protrudes via site of previous abdominal surgery c) Femoral hernia - Protrudes through femoral canal (women more common)

Answer 9

S&S - Visible or palpable bulge [worse with standing, coughing, or straining (↑ intra-abdominal pressure)] - reducible hernia (reduce spontaneously) - happens when intrabdominal pressure goes back to normal - pain or discomfort - nausea or vomiting (obstructed hernia) - localized edema Complications 1) Incarceration - Hernia contents become trapped = unable to return to abdominal cavity - Symptoms: Pain, swelling, nausea 2) Strangulation - Compromised blood supply to herniated tissue = ischemia & necrosis - Symptoms: Severe pain, redness, fever, signs of sepsis Surgical emergency 1) Bowel obstruction - Larger hernias - Symptoms: Abdominal distension, constipation, vomiting Management - surgical repair - mesh implant to reinforce abdominal wall - if mild hernia, you can wait for complications

Answer 10

- small tear or ulcer in lining of anal canal - occurs at posterior midline Causes 1) Trauma during defecation (hard stools or chronic constipation) 2) Prolonged diarrhea or repeated straining 3) Inflammatory conditions (e.g., Crohn’s disease), childbirth, or anal infections

Answer 11

- ↑ anal sphincter tone causes spasm = ↓ blood flow to tear & slowed healing - Repeated trauma leads = chronic fissures, fibrosis, and hypertrophy of surrounding tissues

Answer 12

Acute fissure = Clean tear in mucosa Chronic fissure = Thickened edges, presence of a sentinel skin tag, & hypertrophic anal papillae.

Answer 13

S&S - Pain during & after defecation (sharp, burning) - bleeding (bright red on stool or tissue) - anal spasm - Chronic fissures = surgical intervention (e.g., lateral internal sphincterotomy)

Answer 14

- abnormal epithelialized track connecting anal canal to perianal skin - common for ppl with crohns Cause 1) Abscess from infected anal glands (cryptoglandular theory) 2) Associated with Crohn’s disease, tuberculosis, trauma, or malignancy

Answer 15

- Infected anal glands develop into an abscess = drains into perianal skin = fistula tract formation - Chronic inflammation perpetuates cycle of infection & drainage

Answer 16

- Tract lined with granulation tissue & epithelium - Surrounding tissues may show fibrosis & chronic inflammation

Answer 17

S&S - Persistent drainage of pus or stool from fistula opening - pruritus (itchiness) - discomfort, & pain Complications - Risk of abscess recurrence, fecal incontinence (sphincter muscles involvement), & impaired wound healing (common in crohns who have challenges in healing) - Surgical correction (fistulotomy or seton placement)

Answer 18

- swollen, inflammed veins in anal canal (internal or external) - ↑ venous pressure due to straining during defecation, constipation, prolonged sitting, pregnancy, obesity, or portal hypertension

Answer 19

- Chronic pressure = dilation of vascular cushions in anal canal - Internal hemorrhoids arise from superior rectal vein - External hemorrhoids arise from inferior rectal vein - Prolonged pressure weakens connective tissues = prolapse

Answer 20

Internal hemorrhoids - Occur above dentate line - Covered by mucosa External hemorrhoids - Occur below the dentate line - Covered by skin - Prolonged inflammation = thrombosis or fibrosis

Answer 21

S&S - Internal: Painless rectal bleeding - External: pain and swelling - pruritus - prolapse Complications - Thrombosis (causing severe pain) - anemia (chronic bleeding) - strangulation (prolapsed)

Answer 22

Autoimmune disorder triggered by ingestion of gluten Cause - HLA DQ2 or HLA DQ8 (not everyone with this marker has it, but u need this marker to have it) - ingestion of gluten: triggered immune system to attack itself Patho 1) T cell Activation - modified gluten peptides = produce inflammatory cytokines = intestinal damage 2) B cells generate antibodies 3) Inflammation damages mucosa and causes villous atrophy (flattened villi) Types 1) Classic - classic GI symptoms (diarrhea, pain, bloating) 2) Non-classis: subtle symptoms (anemia, fatigue) - diagnosed later 3) Silent - no symptoms S&S - diarrhea, bloating, abdominal pain Complications - osteoparesis - anemia

Answer 23

Cause 1) Gut microbiome Imbalance - ↑ permeability = inflammation 2) Dysregulation of Gut-Brain Axis - miscommunication between CNS and ENS 3) Fool intolerances Patho 1) Visceral Hypersensitivity - enhanced response to pain and distention - overactive pain signalling and release of neurotransmitters Changes 1) Gut microbiome imbalance 2) Mucosal permeability - ↑ mucosal permeability = leaky gut = allows pathogens and allergens to activate the immune response = inflammation (low-grade) S&S - abdominal pain - bloating and gas