Flashcards in GI Pathology IV: Large Intestine Deck (38):
Involves all 3 wall layers - Mekcel's
Only involves the mucosa and submucosa
Inflammation of the diverticula that can cause pain
Serosal lined outputting of peritoneum - with loops of intestines trapped within the hernia sac
What are the symptoms of ischemic bowel disease?
- Sudden severe abdominal pain
- Bloody diarrhea
What is the pathogenesis of ischemic bowel disease?
Caused due to hypoxic injury and is worsened with the reperfusion injury
Where is the ischemic bowel disease often the worst?
In water shed areas - furthest from circulation - splenic flexure
What is the range of damage seen on the gross findings of ischemic bowel disease?
Can range from mucosal hemorrhage to transmural necrosis of the bowel wall
They are above the pectinate line and are NOT painful
Below the pectinate line and ARE painful
Inflammatory Polyp (Solitary Rectal Ulcer Syndrome)
Sharp angle in the rectum undergoes recurrent abrasion and ulceration that leads to the formation of polyp.
What is the histologic pattern seen with an inflammatory polyp?
Fibromuscular hyperplasia in the lamina propria with some inflammation present
Most are found in children younger than 5 yrs and if solitary, then it is benign, if multiple then there is increased risk of adenocarcinoma
Multiple benign hamartomas throughout the GI tract with hyper pigmentation of the lips, genitals and hands.
The polyps do NOT have malignant potential but patients are at increased risk of colorectal cancer.
Asymptomatic. Look like adenomas with proliferation of mature goblet cells that pile up on each other giving it a serrated appearance.
What are the types of Adenomatous Polyps?
What is the histology of sessile adenomatous polyps?
What is the histology of pendunculated adenomatous polyps?
Sessile Serrated Adenoma
Adenomatous polyp occurring predominantly in the right colon and has malignant potential
Neoplastic epithelium which lines the glands leading to disordered cells with or without mucin production and cells have increased N/C ratio
What is the gene mutation in Familial Adenomatous Polyposis?
Autosomal dominant defect in APC gene on Ch5q21
Autosomal dominant with polyps similar to FAP but with osteomas
Intestinal adenomas with tumors of the CNS - most have APC mutations
Hereditary Nonpolyposis Colorectal Cancer (Lynch Syndrome)
Autosomal dominant mutation of DNA mismatch repair genes that will have a lower number of polyps but with cancer occurring at younger ages than sporadic cancer
What is the function of the APC gene?
APC is an inhibitor of B catenin and mutation in APC will cause B catenin to accumulate and active MYC and cyclin D1 leading to the promotion of proliferation
What cancers do mutations in the DNA mismatch repair cause?
What cancers do mutations in APC cause?
Right Sided CRC
Asymptomatic for a long period of time with signs of iron deficiency anemia from ulceration and blood loss
One what side is the colon larger?
Left Sided CRC
The narrower lumen causes tumors that lead to bowel obstruction with possible blood in the stool
What is the most common type of rectal cancer?
What is the most common type of anal cancer?
Squamous Cell Carcinoma
Obstruction from fecal matter leads to impair blood flow and bacterial contamination with transmural inflammation that leads to RLQ pain
What is seen on histology of appendicitis?
Transmural inflammation full of neutrophils
Benign dilatation of the lumen by mutinous secretions
Proliferation of benign neoplastic cells with dilatation of the lumen by mutinous material and it may rupture
Invasion of neoplastic cells