GI Malignancies & Role of Endoscopy Summary

Tumors of the Esophagus

  • Benign Tumors:

    • Uncommon; commonest are smooth muscle tumors (leiomyoma). Lipomas, hemangiomas, and fibromas are rarer.

    • Squamous cell papilloma (linked to HPV) is the only benign epithelial tumor.

  • Malignant Tumors:

    1. Squamous cell carcinoma

    2. Adenocarcinoma

Gastric Tumors

  • Epithelial

    • Benign: Polyps

    • Malignant: Gastric carcinoma

  • Mesenchymal and Other:

    • Benign: Leiomyoma, Schwannoma, Benign gastrointestinal stromal tumor (GIST)

    • Malignant: Lymphoma, Leiomyosarcoma, Neurogenic sarcoma, Malignant gastrointestinal stromal tumor (GIST)

Colonic Polyps and Neoplastic Disease

  • Polyps

    • Non-Neoplastic

    • Neoplastic

  • Polyposis Syndromes

    • FAP Familial adenomatous polyposis (>100 polyps)

    • Gardner (polyps, osteomas, fibromatosis, keratinous skin cysts)

    • Turcots (I with glioma, II with medulloblastoma)

    • Attenuated FAP (< 100 polyps)

    • Hereditary flat adenomas (old age, proximal ± gastric Ca, <100 lesions)

    • Muir Torre syndrome (polyps <100 with basal or sq cell carcinoma)

    • Hereditary mixed polyposis syndrome (all + atypical juvenile polyps)

    • Cronkite-Canada polyposis syndrome (Lymphoid hyperplasia)

  • Non-Polyposis: HNPCC

Non-Neoplastic Polyps

  • Bilharzial polyps

  • Hyperplastic Polyps: Small sessile polyps, no malignant potential.

  • Pseudopolyps: Small elevations of regenerating epithelium and granulation tissue seen in ulcerative colitis.

  • Hamartomatous Polyps

    • Juvenile polyps: Most common in children; consist of cystically dilated hyperplastic mucous glands.

    • Peutz-Jeghers Syndrome: Mucocutaneous hyperpigmentation and increased risk of malignancies (colon, breast, lung, ovaries, etc.).

Neoplastic Polyps

  • Adenomas:

    • Tubular adenoma (adenomatous polyp)

    • Villous adenoma (papillary adenoma)

    • Tubulo-villous adenoma

Hereditary Non-Polyposis Colorectal Cancer (HNPCC)..Lynch Syndrome

  • Autosomal, dominantly inherited disorder; small number of colorectal adenomas progress to colorectal cancer (right colon).

  • Pseudonyms: Lynch syndromes I and II.

  • Incidence: Accounts for at least 5% of all colorectal cancers.

  • Etiology: Inherited defect in DNA mismatch repair system leads to microsatellite instability.

  • Clinical presentation

    • Onset of colorectal cancer before age 50.

    • First-degree relatives with early onset colorectal cancer (<50y).

    • Extraintestinal cancers (Lynch syndrome II): endometrium, ovary, breast; less often gastric, ovarian, pancreatic.

    • Endoscopic findings: Right-side predominance; small number of polyps with non-exophytic type (flat adenomas) in right colon.

Tumors of Intestine

  • Epithelial tumors

    • Benign: Adenomas

    • Locally Malignant: Carcinoid tumor

    • Malignant: Adenocarcinoma

  • Mesenchymal and other tumors

    • Benign: Leiomyoma, Schwannoma, Lipoma, Fibroma, angioma

    • Malignant: Lymphoma , Leiomyosarcoma

GI Endoscopy

  • Upper GI endoscopy

  • Small bowel enteroscopy

  • Colonoscopy

  • Endoscopic retrograde cholangiopancreatoscpy ERCP

  • Endoscopic ultrasound EUS

  • Capsule endoscopy

Image Enhanced Endoscopy (IEE)

  • Differentiation:

    • Detect a lesion.

    • Modalities: Chromoendoscopy, AFI, LCI, HD endoscopy

  • Characterization:

    • Know what this lesion is.

    • Vascular pattern, morphological classification, fine mucosal structure.

    • Modalities: NBI, BLI, OCT, CLE, Endocytoscopy

Specific IEE Techniques

  • AFI: Autoflorescence Imaging

  • LCI: Linked Color Imaging; enhances detection of sessile serrated adenoma/polyps (SSA/P)

  • Chromoendoscopy

    • Uses chemical compounds as stains/contrast agents to highlight mucosal surface changes or abnormal epithelium.

    • Endoscopic tattooing labels a specific site in the GIT via intramural injection of carbon ink suspension.

Characterization

  • Vascular pattern, morphological classification, fine mucosal structure

  • Image enhanced techniques: High resolution endoscopes, Narrow Band Imaging (NBI), FICE & BLI, I-Scan, etc.

  • Confocal Laser Endomicroscopy (CLE)

  • Endocytoscopy

Vascular Pattern

  • Capillary Network

  • Classified into 4 types (I-IV) according to degree of change in the Intrapapillary Capillary Loop (IPCL) pattern

    • Dilatation

    • Tortuosity

    • Calliber change in 1IPCL

    • Various shapes in multiples of IPCL’s.

Fine Mucosal Pattern Classification: Kudo's Classification

  • Type I: Round pits; Normal histology.

  • Type II: Stellar or papillary, bigger than normal; Hyperplastic, serrated adenoma.

  • Type IIIs: Tubular or roundish, smaller than normal; Adenoma, cancer.

  • Type IIIL: Mostly tubular, larger than normal; Adenoma.

  • Type IV: Sulcus-, branch-, or gyrus-like; Villous adenoma.

  • Type V: Irregular or non-structural; Cancer

NBI International Colorectal Endoscopic Classification (NICE)

  • Type 1: Browner relative to background; None, or isolated lacy vessels; Dark or white spots of uniform size, or homogeneous absence of pattern; Hyperplastic.

  • Type 2: Same or lighter than background; vessels seen; Brown vessels surrounding white structures; Adenoma.

  • Type 3: Brown to dark brown relative to background; Areas of disrupted or missing vessels; Amorphous or absent surface pattern; Deep submucosal invasive cancer

BLI – Blue Laser Imaging

  • Utilizes powerful light emitting diode technology to enhance mucosal surface and vessel patterns.

  • Developed by Fujifilm; brighter NBI

  • Characterization not detection

BLI Classification

  • BASIC (BLI Adenoma Serrated International Classification)

  • To bridge the gap of sessile serrated adenomas in NICE classification

Endocytoscopy

  • Enables visualization of different cytological and architectural features.

  • Malignant features include:

    • Loss of goblet cells.

    • Variable width of the epithelial layer with tubular-shaped (elongated) crypts.

    • The lamina propria is thin and irregular.

    • Fewer blood vessels are present

Determinants of Malignant Transformation

  • Polyp size: Bigger adenoma = higher risk.

    • Exophytic adenomas under 1 cm rarely harbor cancer; lesions over 2 cm = up to 50% chance.

  • Amount of villous component: Malignancy rate is low for tubular adenomas while villous adenomas may reach up to 30-40%.

  • Grading of dysplasia: Malignant potential increases with degree of dysplasia.

  • Polyposis syndromes have increased risk (e.g., 100% in FAP).

  • Malignant transformation in all adenomas is approximately ± 5%.

  • Non-neoplastic polyps (hyperplastic, juvenile, Peutz-Jegher) have negligible rate of malignant transformation.

Impact on Treatment

  • No treatment for benign lesions with no malignant potential

  • Endoscopic treatment for high grade dysplasia lesions limited to mucosa

  • Advanced endoscopic treatment (EMR, ESD) for HGD invading submucosa & intraepithelial carcinomas not reaching the muscularis

  • Surgery for carcinomas invading the muscularis

Surgical Resection Criteria for Large Sessile Polyps

  1. Polyps that laterally encompass more than one third of the bowel circumference

  2. Those that extend longitudinally over 2 successive haustral folds

  3. Lesions that grossly appear to be malignant (irregular, friable, firm/hard, ulcerated, bleeding)

  4. Polyps that extend into the appendix, a diverticulum, or the ileocecal valve