GI Pathology IV: Large Intestine Flashcards
True Diverticulum
Involves all 3 wall layers - Mekcel’s
False Diverticulum
Only involves the mucosa and submucosa
Diverticulitis
Inflammation of the diverticula that can cause pain
Hernia
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
- Tenderness
- Shock
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
Internal Hemorrhoids
They are above the pectinate line and are NOT painful
External Hemorrhoids
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
Juvenile Polyp
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
Peutz-Jeghers Syndrome
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.
Hyperplastic Polyp
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?
- Sessile
- Pedunculated
What is the histology of sessile adenomatous polyps?
Villous
What is the histology of pendunculated adenomatous polyps?
Tubular
Sessile Serrated Adenoma
Adenomatous polyp occurring predominantly in the right colon and has malignant potential
Adenomatous Dysplasia
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
Gardner Syndrome
Autosomal dominant with polyps similar to FAP but with osteomas
Turcots Syndrome
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
