Interpretation of the endoscopic biopsy

GUIDED BY- Brig Vibha Dutta, SMPresented by Maj Ganesh Parajuli

• Introduction

• Technical aspects

• Interpretation

• Pitfalls

• Conclusion

OVERVIEW

• Endoscopy : Examination of internal body cavities using a specialized medical instrument called an endoscope

Introduction

• Fibrooptic endoscopy and biopsy – diagnostic procedure in investigation GI disorder

• The first gastroscope: George Wolf in 1911

• Semiflexible gastroscope: 1930

• Harold designed fibroscope: early 1950

• Newer technologies: chromoendoscopy, capsule endoscopy endoscopic ultrasound

Introduction (contd….)

General features of GI biopsy interpretation

• GI tract: limited repertoire of response to host injuries

• Diagnoses requires correlation with clinical information

• Normal biopsies may be obtained from symptomatic patients

• Inflammatory cells are a normal constituent of lamina propia

Overview comments on the GI tract

epithelium – protective, absorbtive & secretory

lamina propria – thin loose CT

muscularis mucosa – slim double layer of smooth muscle

Mucosa

Submucosa

Muscularis propria

Skeletal muscle at beginning & smooth muscle at the end(inner circular; outer longitudinal layer) from lower esophagus to rectum

Serosa

(viseral peritoneum)

4 layers of tissue surround the lumen of the GIT

The major uses of mucosal biopsy includes:

i. Diagnosis : either specific or in the form of an injury pattern or stage

ii. Determination of the extent or severity of lesions

iii. Monitoring of the clinical course of disease states with particular reference to effects of therapy

iv. Detection of complication

Clinical pathological correlation is essential for diagnosis-

The following clinical data should be provided :1. Age, race and sex of the patient

2. Sign and symptoms, site of biopsy, endoscopic and radiological finding

3. History of taking drugs or alcohol

4. Medical and surgical history

Assessing any biopsy from GI tract

Technical aspects • The grasp biopsy specimens obtained at flexible endoscopy

typically consists only of the mucosa

Regions with thicker mucosa contain only superficial portion

• Suction or aspiration-type biopsy more fruitful when a larger sample or more exact location is required

• Choice of fixative is usually not critical though Bouin’s may interfere with staining of the granules of Paneth cells

• Multiple sections to improve the chance of detecting any focal or subtle changes

• For routine analysis at least 3 levels of biopsy specimen, each with 5 or more sections

• When focal lesion not obtained, additional levels should be require

• Cytologic preparations useful diagnostic adjunct

Ideal Mucosal Biopsy

• At least 3 pieces of full thickness mucosa 3 mm in length • Mucosal fragments well oriented at time of embedding

crypt:villous ratio can accurately evaluated

Abnormal esophagealmucosa

Neoplastic

BenignInfections Others

Squamous papilloma Squamous cell carcinomaAdenocarcinoma

Corrosive - lyeReflux

Viral- Herpes simplex CMVFungal- Candida

Non neoplastic

Abnormal esophageal Mucosal Biopsy

Malignant

Esophagitis The 4 most common types of esophagitis:

1. Pill esophagitis– Spectrum of injury by the ingestion of drugs – Common site anatomical narrowing– Ulcer ,granulation tissue ,polarizable foreign material and

multinucleted gaint cells

2. Infectious:– HSV, CMV (BMT, solid organ transplant)– Candidal (HIV, thrush associated) Yeast and pseudohypae seen in necroinflammatory

background

3. Eosinonophilic esophagitis: frequently seen in childern

Endoscopic finding –stricture , rings corrugation,furrows and granularity

Mucosal edema ,basal cell hyperplasia with eosinophil infiltration of sq mucosa >20 eosinophil per high field

4.Reflux disease

• GERD the costliest GI disorder & the most common physician diagnosis GI disorder in outpatient clinic visit

• GERD caused by reflux of gastric contents into esophagus

Reflux of gastric acid and pepsin

• Reflux of alkaline bile & pancreatic secretion moving from duodenum stomach esophagus recognized as a contributing factor to esophageal injury in GERD

• ‘Reflux esophagitis ‘ an example of ‘itis ‘ lack prominent component of inflammation

• The pathology reflects injury to sq epithelium followed by attempts of the epithelium to regenerate

• Mild features of cellular injury- balloon cells vascular lakes, mild inflammation and scattered eosinophils

REFLUX/GERD

Fairly reproducible criteria established by Fiocca et al as abnormal and associated with clinical reflux –

i. Thickened basal layer(>15%) or 5 to 6 layersii. Increased papillary length (>50%) of the squamous thicknessiii. Intraepithelial eosinophil ,neutrophil (>1to 2 cells /40x field)iv. Intraepithelial mononuclear cells.(>10/40x field)v. Dilated /widened inter cellular spaces(which may appear as

bubbles or ladders.

BARRETT’S ESOPHAGUS

• Defined as intestinal metaplasia of a normally SQUAMOUS esophageal mucosa.

• The presence of GOBLET CELLS in the esophageal mucosa is DIAGNOSTIC.

• SINGLE most common RISK FACTOR for esophageal adenocarcinoma

• 10% of GERD patients get it• “BREACHED” G-E junction

BARRETT’S ESOPHAGUS

Gastritis• No widely accepted classification of gastritis• Updated Sydney System Published in 1997• Attempted to combine topographical, morphological and etiological information • Largely unused bec of inadequate sampling & clinical information ,poor endoscopic &

histologic correlation and ethic and geographic variation of the disease

Operative Link for Gastritis Assessment (OLGA) staging system: Based on extent and severity of atrophic gastritis and provide relevant clinical information

regarding the gastric cancer risk.However, atrophic gastritis is a difficult histopathological diagnosis of which the

interobserver agreement is low.

Operative Link for Gastritis Assessment (OLGA) staging system: -Extent and severity of atrophic gastritis

H pylori associated gastritis

• Helicobacter pylori (H pylori) common bacterium that is present in millions of people worldwide

• found in mucous lining of stomach. It is known to be responsible for 60% to 80% of gastric ulcers and 70% to 90% of duodenal ulcers

• The recognition of an association between this bacterium and peptic ulcer disease by Barry Marshall and John R. Warren, in 1983, and they were awarded the Nobel prize in 2005

• Another varient called H. heilmannii (less than 1% isolates)• Like H pylori it produces antral predominant gastritis ,less sev, than

H. pylori gastritis

• Histologically shows organisms within the surface mucus layer and foveolar epithelium

• Abundant, lymphoplasmacytic , chronic inflammation of lamina propria

• Presence of lymphoid follicles (MALT) almost always indicative of infection

A simplified pathology report of gastritis include the following

parameters:a. Type of mucosa

b. Grade of lymphoplasmacytic infiltration (4 M)

c. Presence or absence of active inflammation with degree of activity(if present)

d. Extent of intestional metaplasia or atrophy(if present)

e. Presence or absence of H pylori microorganism

Normal histology

• Finger-like villi

• C:V ratio (assessed where 4 well-oriented crypts and villi are seen)

• Normal C:V ratio 1:3 or more

• C:V ratio lower in children and elderly

• C:V ratio usually uniform in a biopsy

Evaluation of small intestinal mucosal biopsy

Low power • adequacy of biopsy• crypt villous architecture• degree of inflammation

High power• Specific features in lumen, epithelium and lamina

propria

Indications for biopsy:

• Evaluation for patients with malabsorption• Investigation for patients with iron deficiency anemia,

diarrhoea particularly in whom infections is suspected with AIDS

• Diagnosis of neoplasia• Confirmation of ulceration induced by NSAID or in cases of

bleeding from unknown site.

Benign polypsAdenocarcinomasEndocrineLymphomasGISTsWaldenstrom’s

Abnormal small intestinal mucosa

Specific changes

Epithelial Lamina propria

Infections InfectionsOthers Inflammatory Metabolic Neoplasms

Celiac diseaseTropical sprueBacterial overgrowthCow’s milk allergyChronic renal failureB12, folate, iron, zinc defAutoimmune enteropathyDrugs

ViralParasiticFungal

lBDGranulomatousCollagenousEosinophilicImmunodeficiencyAutoimmune enterop

AmyloidosisStorage disorders

LymphocyticAbetalipoprot.Microvillous incGVHDAIDS enteropathyl

ViralParasiticBacterial

Nonspecific changes

Abnormal Small Intestinal Mucosal Biopsy

Lumen parasites

Spectrum of Nonspecific inflammatory changes in the small intestinal mucosa

Architecture• Crypt hyperplasia• Crypt hyperplasia with villous atrophy • Villous atrophy with crypt hypoplasia (rare)• Branching, broadening and fusion of villi (mild cases)

Epithelium• Epithelial damage: flattening, nuclear irregularity, loss of polarity,

vacuolization, basophilia• Increased intraepithelial lymphocytes• Increased apoptosis• Macrocytosis of epithelial cells

Lamina propria• Chronic inflammation• Acute inflammation

Varying degrees of change

mild

sevmod

Celiac disease

Macroscopic features• On endoscopy the mucosa appear flattened and scalloped if

there is significant villous atrophy

Microscopic features• Microscopic changes most severe in duodenum and decrease

in severity distally• 4 small intestinal biopsies are required for absolute diagnostic

confidence (Pais et el, Gastroint Endosc 2008); • May be patchy• Changes decrease with gluten withdrawal and recur when

gluten is re-introduced

Celiac disease : Spectrum of changesMarsh’s diagnostic criteria

• 0 – preinfiltrative: Dermatitis herpetiformis; no mucosal change

• I More than 40 intraepithelial lymphocytes per 100 epithelial cells – infiltrative

• II. Crypt hyperplasia with increased intraepithelial lymphocytes – infiltrative type 2

• III. Crypt hyperplasia with increased intraepithelial lymphocytes and villous atrophy

• IIIa Mild villous atrophy• IIIb Moderate villous atrophy• IIIc Severe villous atrophy

• IV Crypt hypoplasia with villous atrophy

Tropical sprue

• Chronic malabsorptive syndrome seen in residents and visitors to tropical countries

• Etiology related to chronic infections and bacterial overgrowth

• Entire small intestine from duodenum to terminal ileum may be involved

• Villous atrophy, crypt hyperplasia, inflammation and increased IELs

• Often responds to broad spectrum antibiotics like tetracycline

Cow’s milk protein allergy

• Temporary condition affecting young infants presented with malabsorption & dehydration requiring parenteral nutrition

• Bloody diarrrhoea, vomiting, abdominal pain, weight loss

• Small intestional mucosal changes similar to celiac disease but lesser extent

• Intraepithelial eosinophils & peripheral eosinophil are more noted with cow’s milk

Nutritional deficiences

Vitamin B12, protein, iron and zinc deficiency

Structural abnormalities of intestional mucosa

associated with malsorption

• B12: villous blunting, macrocytosis, decreased mitoses

• Protein deficiency

• Zinc deficiency

AIDS enteropathy

• Individuals infected with HIV with chronic diarrhoea have opportunistic infections or diffuse small intestional mucosal alterations in the absence of pathogens

• Duodenal biopsies may shows crypt hyperplasia and partial villous atrophy, increased intraepithelial lymphocytes and infiltration of the lamina propria by plasma cells and lymphocytes

• Crypts shows evidence of increase apoptotic activity

Specific changes in Small intestinal biopsies

Lumen

Giardia Lamblia

InfectionsGiardiasis

• Most common parasitic infection

• Presence of trophozoites in fecal and duodenal biopsy specimen confirm giardia infection

• Duodenum (more than 80%) followed by jejunum and ileum, rarely the stomach and colon

• The mucosa is normal shows minimal changes in majority of cases with mild villous atrophy, crypt hyperplasia , loss of normal brush border shorting of villous epithelium and increase intraepithelial lymphocytes

• The parasite found in lumen close to the surface of villous epithelium

Specific changes in Small intestinal biopsies

Epithelium

Lymphocytic enteritis

Increased intraepithelial lymphocytes

• Definition: • > 30 or 40/100 villous epithelial

cells • Or more than 5 per 20 villous tip

epithelial cells

• Should be diffuse

• Counting should not be done over a lymphoid follicle

Causes • Infections• H.pylori infection • Tropical sprue• Celiac sprue• Refractory sprue• Protein intolerance• NSAIDs• Bacterial overgrowth• IBD• Lymphocytic enteritis• AIDS, hypogammaglobulinemia• Collagen vascular disease

Acute GVHD

Endoscopic findings• Normal mucosa, erythema, ulcers and sloughing

Histologic features• Single cell apoptosis in crypts• Villous blunting• Loss of crypts

• D/D: CMV infection; chemoradiation-induced damage

Chronic GVHD

Epithelial infections

Viral – nonspecific changes except CMV

Bacterial – Enteropathogenic E.coli may form colonies on the brush border

Parasitic - • Microspora – genera Encephalitozoon, Enterocytozoon• Isospora• Cryptosporidium• Cyclospora

Cryptosporidiosis

• Cryptosporodium parvum protozoan, highly infectious with waterborne ,person to person

• Immunocompetent pts acute ,self limiting diarrhoea while immunocompromised pts including AIDs chronic watery dairrhoea

• Distribution worldwide ,endemic in developing countries, found in >50%of AIDS

Cryptosporidiosis

Microsporidiasis

Widespread obligate intracellular parasite Opportunistic infection in immunosuppressed organ transplant patents

and those with AIDS The infection includes : Enterocytozoon bieneusi & Encephalitozoon intestinalis Histological features : In small bowel both causes a partial villous atrophy ,mild crypt hyperplasia

with short blunt villi and mild increase in lymphocytes ,plasma cells & eosinophil in the lamina propria

Microsporidiosis

Encephalitozoon intestinalis

Entercytozoon bieneusi

Specific changes in Small intestinal biopsies

Lamina propria

Specific changes in the lamina propria

Infections• Parasitic: Isospora• Viral: CMV• Bacterial: TB, MAI, Whipple’s, yersinia• Fungal: Histoplasma, cryptococcus

IBD• Crohn’s

Allergic• Eosinophilic enteritis• Lymphocytic/collagenous enteritis

Immune• Immunodeficiency syndromes

Vascular• Radiation enteritis• Vasculitis• Ischemia• Portal hypertension

Others• Amyloidosis• Lymphoma

CMV

Macroscopic• Patchy erythema, edema, aphthous and deep penetrating ulcers

Microscopic• Usually endothelial cells and other stromal cells deep in the base of ulcers

and other sites; rarely epithelial

• less inflammation in immunocompromised individuals

• Atypical inclusions: smudged nuclei

Other diagnostic tests: immunohistochemistry and PCR

Histoplasmosis

• Macroscopic:• Nodular or ulcerating lesions in ileum

• Microscopic:• Granulomas• Fungal bodies in the cytoplasm of histiocytes; small oval yeast

forms with buds at the pointed ends

Mycobacterium Avium Complex • Commonly affects small intestine (duodenum most frequent) and colon of

immunocompromised individuals (AIDS with CD4 counts <60/mm3

• On endoscopy: coarse granularity, edema, erythema, yellowish streaks or ulcers

• On histology – • immunocompetent individuals show necrotizing (up to 30%, small foci) or

nonnecrotizing granulomatous inflammation; • immunodeficient individuals : diffuse infiltrates of histiocytes with foamy

or granular cytoplasm and minimal other inflammatory cells• Regional lymph nodes enlarged with similar cells

• AFB and PAS positive (fibrillary appearance versus granular appearance of Whipple’s)

• EM: intact bacteria

• Mycobacterium Avium Complex • Ziehl Neelsen

Eosinophilic enteritis

• Often associated with peripheral eosinophilia (75%) and allergic disorders

• Eosinophilia may be confined to the mucosa or involve the muscle coat or serosa

• May present with hemorrhage, chronic diarrhea, abdominal pain, malabsorption, protein losing enteropathy, obstruction or ascites

• D/D: parasitic infections, vaculitis, Crohn’s disease, Gluten sensitivity, lymphomas, inflammatory fibroid polyp, magnesium, vitamin E or selenium deficiency

Eosinophilic Enteritis

(I) IBD

• CROHN DISEASE (granulomatous colitis)

• ULCERATIVE COLITIS

(I) IBD

• COMMON FEATURES– IDIOPATHIC– DEVELOPED COUNTRIES– COLONIC INFLAMMATION– SIMILAR Rx– BOTH have CANCER RISK

(I) IBD DIFFERENCES

• CROHN (CD)– TRANSMURAL, THICK WALL– NOT LIMITED to COLON– GRANULOMAS– FISTULAE COMMON– TERMINAL ILEUM OFTEN– SKIP AREAS– “CRYPT” ABSCESSES NOT COMMON– NO PSEUDOPOLYPS– MALABSORPTION

• ULCERATIVE (UC)– MUCOSAL, THICK MUCOSA– LIMITED to COLON– NO GRANULOMAS– FISTULAE RARE– TERMINAL ILEUM NEVER– NO SKIP AREAS– “CRYPT” ABSCESSES COMMON– PSEUDOPOLYPS– NO MALABSORPTION

Intestinal TB versus Crohn’s diseaseTuberculosis:Granulomas• Caseation• Confluent granulomas• Lymphoid cuff • Granulomas larger than 400 micrometer• 5 or more granulomas in biopsies from one

segment• Granulomas located in the submucosa or

in granulation tissue: often with palisaded histiocytes

• Granulomas in the ileocecal region

• Nonspecific inflammatory changes in the same and adjacent segments to those with granulomatous iflammation

• Disproportionate submucosal inflammation

Crohn’s disease:Granulomas• Small (<200 micrometer) • Discrete• Very few / single • Poorly organised • Commonly located in the mucosa• Granulomas in the rectosigmoid• “microgranulomas”: aggregates of

histiocytes

• Nonspecific inflammation more diffusely distributed and not restricted to the same segments or those adjacent to the sites of granulomatous iflammation

• Crypt-centric inflammation: pericryptal granulomas and focally enhanced colitis

Crohn’s disease

• Segmental, patchy and focal involvement• Distorted crypt villous architecture, Villous atrophy• Significant chronic inflammation• Increased intraepithelial lymphocytes, cryptitis, ulceration• Granulomas, microgranulomas

Amyloidosis

• G.I. involvement occurs in 85 to 100% cases of systemic amyloidosis

• Commonly causes ulceration, bleeding; motility disorders, stasis and malabsorption

• Macroscopy: fine granularity, erosions, friability, thickening of folds

Take home message

Interpretation & evaluation of GI biopsy specimen requires clinicopathological correlation

Good orientation of the biopsy specimen essential for accurate histopathological assessment.

A well-oriented biopsy specimen should have at least 4-5 consecutive elongated ,well distended villi from the base of the tip

The evaluation of the villous: crypt ratio, the count and distribution of the intraepithelial lymphocytes(IELs) as well as the evaluation of the enterocytes in the tip is critical

Infections can be accompanied by subtle changes in the architecture and minimal inflammation

References

• Biopsy Interpretation of the Gastro intestional tract mucosa , Elizabeth A. Montigomery & Lysandra voltaggia .2nd Edition

• Mucosal biopsy of the Gastrointestional tract,Whitehead 2nd edition

• Morson and Dowson’s Gastrointestional Pathology,David W Day 4th edition

• Robbins and Cortan Pathologic Basis of Disease 8th edition• Sternberg’s Diagnostic Surgical Pathology, Stancy E.Mills 5th

editon• Wheater’s Functional Histology, Barbara Young , Alan,James

5th edition

• Pathology illustrated, Robin Reid, Foina, Elaime. 7th edition

• S serra, P A Jane. An approach to duodenal biopsies J Clin Pathol2006;

• Harvey Goldman, Donald. Mucosal biopsy of the esophagus ,stomach, and proximal duodenum Human pathology

• Netter’s illustrated Human Pathology, Gerhard, L.M. Buja.1st edition