Gastrointestinal Malignancies and Endoscopy

Tumors of the Esophagus

  • Benign Tumors
    • Uncommon.
    • Commonest are smooth muscle tumors (leiomyoma).
    • Lipomas, hemangiomas, and fibromas are rarer.
    • The only benign epithelial tumor is squamous cell papilloma, potentially linked to human papillomavirus (HPV) infection.
  • Malignant Tumors
    • Squamous cell carcinoma
    • Adenocarcinoma (often arising on top of Barrett's esophagus)

Gastric Tumors

  • Epithelial Tumors
    • Benign: Polyps
    • Malignant: Gastric carcinoma
  • Mesenchymal and Other Tumors
    • 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 Polyps
    • Neoplastic Polyps
  • Polyposis Syndromes
    • FAP: Familial adenomatous polyposis (>100 polyps)
    • Gardner syndrome: Polyps, osteomas, fibromatosis, keratinous skin cysts
    • Turcot syndrome:
      • Type I: With glioma
      • Type II: With medulloblastoma
    • Attenuated FAP: < 100 polyps
    • Hereditary flat adenomas: Old age, proximal colon involvement, possibly gastric cancer, <100 lesions
    • Muir-Torre syndrome: <100 polyps with basal or squamous cell carcinoma
    • Hereditary mixed polyposis syndrome: All types + atypical juvenile polyps
    • Cronkite-Canada polyposis syndrome: Lymphoid hyperplasia
  • Non-Polyposis
    • HNPCC: Hereditary Non-Polyposis Colorectal Cancer (Lynch Syndrome)

Non-Neoplastic Polyps

  • Bilharzial polyps (associated with Schistosomiasis).
  • Hyperplastic Polyps
    • Small, sessile polyps.
    • Have no malignant potential.
  • Pseudopolyps
    • Small elevations of regenerating epithelium and granulation tissue, seen in ulcerative colitis.
  • Hamartomatous Polyps
    • Juvenile Polyps
      • Most common type in children.
      • Consist of cystically dilated hyperplastic mucous glands filled with retained secretion.
    • Peutz-Jeghers Syndrome
      • Important to recognize due to associated intestinal and extraintestinal manifestations.
      • Mucocutaneous hyperpigmentation.
      • Increased risk of several malignancies, such as cancer of the colon, breast, lung, ovaries, and others.

Neoplastic Polyps

  • Adenomas
    • Tubular adenoma (adenomatous polyp).
    • Villous adenoma (papillary adenoma).
    • Tubulo-villous adenoma.

Polyposis Syndromes (Detailed)

  • FAP: Familial Adenomatous Polyposis
    • Characterized by >100 polyps.
  • Gardner Syndrome
    • Features polyps, osteomas, fibromatosis, and keratinous skin cysts.
  • Turcot Syndrome
    • Type I associated with glioma.
    • Type II associated with medulloblastoma.
  • Attenuated FAP
    • Involves <100 polyps.
  • Hereditary Flat Adenomas
    • Occurs in old age, with proximal colon involvement and possible gastric cancer; <100 lesionspresent.
  • Muir Torre Syndrome
    • Features <100 polyps with basal or squamous cell carcinoma.
  • Hereditary Mixed Polyposis Syndrome
    • Presents with all types of polyps, including atypical juvenile polyps.
  • Cronkite-Canada Polyposis Syndrome
    • Characterized by lymphoid hyperplasia.

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

  • Definition
    • An autosomal, dominantly inherited disorder.
    • Characterized by the development of a small number of colorectal adenomas that frequently progress into colorectal cancer, preferentially in the right colon.
  • Pseudonyms
    • Also referred to as Lynch syndromes I and II.
  • Incidence
    • May account for at least 5% of all colorectal cancers.
  • Etiology and Pathogenesis
    • Inherited defect in the DNA mismatch repair system, leading to microsatellite instability.

Hereditary Non-Polyposis Colorectal Cancer (HNPCC) - Clinical Presentation

  • Clinical Presentation
    • Onset of colorectal cancer before the age of 50.
    • First-degree relatives with a history of early onset of colorectal cancer (<50 years), involving at least two generations.
    • Extraintestinal cancers in some kindreds (Lynch syndrome II), especially endometrium, ovary, and breast.
    • Less often gastric, ovarian, pancreatic, and transitional cell carcinoma of the ureter and renal pelvis.
  • Endoscopic Findings
    • Colorectal cancers with right-side predominance.
    • On the early stage of disease, a small number of polyps throughout the colon with predominance of the non-exophytic type (flat adenomas) for the right colon.

Tumors of the 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 cholangiopancreatography (ERCP)
  • Endoscopic ultrasound (EUS)
  • Capsule endoscopy

Role of GI Endoscopy

  • Role in early detection of GI malignancy

Image Enhanced Endoscopy (IEE)

  • Differentiation
    • To detect a lesion
    • Modalities:
      • Chromoendoscopy
      • AFI (Autofluorescence Imaging)
      • LCI (Linked Color Imaging)
      • HD endoscopy
  • Characterization
    • To know what this lesion is
    • Vascular pattern
    • Morphological classification
    • Fine mucosal structure
    • Modalities:
      • NBI (Narrow Band Imaging)
      • BLI (Blue Light Imaging)
      • OCT (Optical Coherence Tomography)
      • CLE (Confocal Laser Endomicroscopy)
      • Endocytoscopy

Image Enhanced Endoscopy Technologies

  • AFI: Autofluorescence Imaging
  • LCI: Linked Color Imaging
    • SSA/P (Sessile Serrated Adenoma/Polyps) better detected by LCI.

Chromoendoscopy

  • Developed in Japan in the 1970s.
  • Uses chemical compounds as stains or contrast agents to highlight subtle mucosal surface changes or abnormal gastrointestinal epithelium.
  • Endoscopic tattooing
    • A technique where a specific site in the GIT is labeled by an intramural injection of a carbon ink suspension solution for future surgical or endoscopic identification.

Characterization (Detailed)

  • 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 Classification

  • Capillary Network
    • Classified into 4 types (I-IV) according to the degree of change in the Intrapapillary Capillary Loop (IPCL) pattern.
      • Dilatation
      • Tortuosity
      • Caliber change in 1 IPCL
      • Various shapes in multiples of IPCLs.

Fine Mucosal Pattern Classification - Kudo's Classification

  • Type I: Round pits; Normal histology.
  • Type II: Stellar or papillary pits, bigger than normal; Hyperplastic, serrated adenoma.
  • Type IIIs: Tubular or roundish pits, smaller than normal; Adenoma, cancer.
  • Type IIIL: Mostly tubular pits, larger than normal; Adenoma.
  • Type IV: Sulcus-, branch-, or gyrus-like pits; Villous adenoma.
  • Type V: Irregular or non-structural pits; Cancer.

Kudo's Classification - Description and Treatment

  • Type I: Round pits; Non-neoplastic; Endoscopic or none.
  • Type II: Stellar or papillary pits; Non-neoplastic; Endoscopic or none.
  • Type IIIs: Small tubular or round pits that are smaller than the normal pit; Neoplastic; Endoscopic.
  • Type IIIL: Tubular or roundish pits that are larger than the normal pits; Neoplastic; Endoscopic.
  • Type IV: Branch-like or gyrus-like pits; Neoplastic; Endoscopic.
  • Type VN: Irregularly arranged pits with type IIIs, IIIL, IV type pit patterns; Neoplastic (invasive); Endoscopic or surgical.
  • Non-structural pits: Neoplastic (massive submucosal invasive); Surgical.

NBI International Colorectal Endoscopic Classification (NICE)

  • Type 1: Browner relative to background; None, or isolated lacy vessels coursing across the lesion; Dark or white spots of uniform size, or homogeneous absence of pattern; Hyperplastic.
  • Type 2: Same or lighter than background (verify color arises from vessels); Brown vessels surrounding white vessels; Has areals) of disrupted or missing Structures; Adenoma***.
  • Type 3: Brown to dark brown relative to background; sometimes patchy whiter areas; Oval, tubular or branched white structure surrounded by brown vessels; Amorphous or absent surface pattern; Deep submucosal invasive cancer.

BLI – Blue Laser Imaging

  • Blue Laser Imaging (BLI) is a new technology that 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, which distinguishes between hyperplastic and adenomatous polyps but does not have a category for serrated lesions.
  • Thus, the dutch WASP & BASIC classifications were developed.

Confocal Laser Endomicroscopy (CLE)

  • A technique that provides high-resolution, real-time imaging of the gastrointestinal mucosa at a cellular level.

Endocytoscopy

  • Enables visualization of different cytological and architectural features, including size, arrangement, and density of cells.

Malignant Features (Endocytoscopy)

  • Loss of goblet cells.
  • Variable width of the epithelial layer with tubular-shaped (elongated) crypts.
  • The lamina propria is thin and irregular.
  • Due to the volume loss in the lamina propria, fewer blood vessels are present.

Determinants of Malignant Transformation in Polyps

  • Polyp size
    • The bigger the adenoma, the higher the risk of malignancy.
    • Exophytic adenomas under 1 cm very seldom harbor cancer, while lesions over 2 cm in up to 50% of cases harbor cancer.
  • The amount of villous component.
    • The malignancy rate for tubular adenomas is low, while in villous adenomas it's up to 30-40%.
    • Small adenomas are usually of tubular type. As they grow, the villous component increases.
  • The grading of dysplasia.
    • The malignant potential of adenomas increases with increasing degrees of dysplasia.
    • The grade of dysplasia is directly related to size and villous component.

Malignant Transformation Risk

  • Polyposis syndromes
    • Are at an increased risk of malignant transformation, e.g., 100% in FAP.
  • Round figure of malignant transformation in all adenomas is approximately 5%.
  • Non-neoplastic polyps
    • E.g., hyperplastic (especially if solitary), Juvenile, Peutz-Jeghers have a 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 the mucosa.
  • Advanced endoscopic treatment (EMR, ESD) for HGD invading the submucosa & intraepithelial carcinomas not reaching the muscularis propria.
  • Surgery for carcinomas invading the muscularis propria.

Criteria for Surgical Resection of Polyps

  • Generally accepted criteria for large sessile polyps that should be referred for surgical removal:
    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 (e.g., irregular, friable, firm/hard, ulcerated, bleeding).
    4. Polyps that extend into the appendix, a diverticulum, or the ileocecal valve, or otherwise wrap around a sharp fold.

Endoscopist Experience and Polyp Removal

  • Large polyps are associated with a higher rate of complications.
  • Some polyps will require surgical removal, but the best gauge of whether a given endoscopist should attempt removal is the degree of experience and level of comfort of that endoscopist.

Role of GI Endoscopy in Management of Early GI Malignancy

  • Polypectomy
  • Endoscopic Mucosal Resection (EMR)
  • Endoscopic Submucosal Dissection (ESD)