Differential Diagnosis of Adenomas

8/14/2019 Differential Diagnosis of Adenomas

http://slidepdf.com/reader/full/differential-diagnosis-of-adenomas 1/35

Group 2Section BMHAM College of Medicine



Case:

A 45 Year old Man with a FamilyHistory of Colon CA undergoes ascreening colonoscopy. No

Invasive Ca, but 2 smallpedunculated tubular adenomas& 1 villous adenomas 5 mm.





Adenocarcinoma is a canceroriginating in glandular tissue. Thistissue is also part of a larger tissuecategory known as epithelial.Epithelial tissue includes, but is notlimited to, skin, glands and a variety

of other tissue that lines the cavitiesand organs of the body

http://en.wikipedia.org/wiki/Glandular

http://en.wikipedia.org/wiki/Epithelial

http://en.wikipedia.org/wiki/Epithelial

http://en.wikipedia.org/wiki/Glandular



Morphology

one will see a mass thatlooks of a different color thanthe surrounding tissue.

Histologically, a glandularstructure, similar to thehealthy normal surroundingglands may be seen.

If they look very similar, thisis a low grade, well

differentiated tumor. Often these glands will be

disorganized and they will beseen growing back to back.

However, if the tumordoes not look like a gland

anymore, it is a highgrade tumor with poordifferentiation.

Regardless of the grade,malignant tumors tend tohave a large nucleus with

prominent nucleoli. There will also be a

noticeable increase inthe incidence of mitoses,or cell divisions



GROSS MICROSCOPIC

http://upload.wikimedia.org/wikipedia/commons/4/44/Colon_cancer.jpg

http://upload.wikimedia.org/wikipedia/commons/4/44/Colon_cancer.jpg



Benign adenomas (NeoplasticPolyps)

• Polyps arise from dysplastic epithelium• 50% after age 60

• 90% : in the colon; maybe single or multiple

• divided by histology into 4 types – Tubular adenoma: small, but become pendunculated as they

grow – Villous adenoma: large, frondlike projection, sessile

– Tubulovillous adenoma: intermediate in size, stalk& mixedarchitecture

– Serrated adenoma: mixture of hyperplastic polyp and adenoma

•

greater than 1 cm, (>25%) villous component, or havehigh-grade dysplasia are commonly referred to asadvanced neoplasms and carry an increased cancer risk.





• All patients will develop colorectalcancer from the colon polyps usuallyby age 40.

• Patients with FAP must have the colon,and sometimes the rectum, removedto prevent colon cancer.

• In over 80 percent of patients with FAP,

polyps form in the stomach and smallintestine. The polyps found in theupper portion of the stomach are calledfundic gland polyps.



• The polyps found in the bottom of thestomach (the antrum) most often areprecancerous polyps called adenomas.

• Polyps in the duodenum (the first part of the small intestine) are adenomas and canturn into cancer .

• Duodenal polyps can be very subtle and

hard to detect, or they may be obvious andcover a large segment of the duodenum.



polyps duodenum



They are often found at the openingof the bile duct and the duodenum,called the papilla. Because of thegreat number of polyps, they areusually not removed.



Gross MorphologyFamilial polyposis of the

colon Familial adenomatous polyposis: theentire colonic mucosa is carpeted with aclose crop of polyps.



Microscopic Morphology

Familial polyposis of thecolonThe changes are subtle .This slide shows the subtle changes in thebowel mucosa that can lead to big troubleslater. BENIGN



MORPHOLOGY OF CARCINOID

TUMOR Appendix is the most commonsite followed by a smallintestine (primarily ileum),rectum, stomach, and colon.

In the appendix, it appearsbulbous swelling of the tip,which frequently obliteratethe lumen.

Elsewhere in the gut, theyappear as intramural orsubmucosal masses thatcreate small, polypoid orplateau-like elevations rarelymore than 3 cm.



Morphology

Solid, yellow-tan appearance, firmdue to desmoplasia.

Rectal and appendiceal carcinoidsalmost never metastasize



Microscopic

The neoplastics cells formdiscrete islands, trabeculae,strands, glands orundifferentiated sheets.

Monotonous appearance withscanty pinkish granularcytoplasm, round to ovalstippled nucleus.

In most tumors, there is

minimal variation in cell andnuclear size and mitoses areinfrequent or absent.

DIAGNOSISOCCURENC FAMILISize/ Morphology/ impression



DIAGNOSISOCCURENCE

FAMILIALPRED.

Size/multiplicity

Morphology/invasiveness

impression

AdenoCa 40-70 yo+

3 cmsingle

Exophylic -sessileinvasive

Rule in

Adenoma(benign)

40-60 yo+

< 5cmsingle

Small,pedunculatedNon invasive

Rule in

Hyperplasticpolyps

60 andabove

- < 5 cmsingle

Nipple-likeNon-invasive

Rule out

Harmatoma(Peutz Jehger)

9 yo andabove +

Smallmultiple

PolypoidsNon-invasive

Rule out

Gastro-

Intestinaltumors

- - < 4cm

multiple

Fugating/

ulceratinginvasive

Rule out

FamilialAdenomatous polyps

Children+

multiple PolypoidRisk to AdenoCa

Rule out

InflammatoryPolyps all + Multiple Inflammed mucosaUlcerating; Non invsv.Rule out







Laboratory test

Stool Examination: Fecal Occult Blood Testing

Hemoccult is composed of guaiacimpregnated paper enclosed in acardboard frame which permits sampleapplication to one side, and developmentand interpretation on the reverse side.

The process involves placing twospecimens, collected from each of threesuccessive evacuations, onto the guaiacpaper.



Hemoccult is based on the oxidation of guaiac by hydrogen peroxide to a bluecolored compound.

The heme portion of hemoglobin, if presentin the fecal specimen, has peroxide activitywhich catalyzes the oxidation of alphaguaiaconic acid (active component of theguaiac paper) by hydrogen peroxide (activecomponent of the developer) to form ahighly conjugated blue quinone compound.



Hemoccult test willshow hidden blood inthe stool in early

curable stages of colon cancer. Evenbetter, as in thiscase, the Hemocculttest may be positive

even before cancercells have developed.



Blood Testing

Reticulocytosis Abnormal Lab Findings - Decreased

MCH (Lab)

MCHC (Lab) MCV/Mean Corpuscular Volume (Lab)

Abnormal Lab Findings - Increased Hemoglobin (Lab)

Polychrome RBCs (Lab) Reticulocytes (Lab) TIBC/Total Iron Binding capacity (Lab)



Barium Enema

The doctor puts a liquid calledbarium into your rectum beforetaking x rays of your large intestine.Barium makes your intestine lookwhite in the pictures. Polyps aredark, so they’re easy to see.





Sigmoidoscopy

With this test, the doctor puts a thin,flexible tube into your rectum. Thetube is called a sigmoidoscope, andit has a light in it. The doctor usesthe sigmoidoscope to look at the lastthird of your large intestine.





Colonoscopy

The doctor will give you medicine tosedate you during the colonoscopy.

This test is like the sigmoidoscopy,but the doctor looks at the entirelarge intestine with a long, flexibletube with a camera that shows

images on a TV screen. The tube hasa tool that can remove polyps. Thedoctor usually removes polyps duringcolonoscopy.





Computerized Tomography

Scan• With this test, also called virtual

colonoscopy. A machine using x rays andcomputers creates pictures of the large

intestine that can be seen on a screen.• The CT scan takes less time than a

colonoscopy because polyps are notremoved during the test. If the CT scan

shows polyps, you will need a colonoscopyso they can be removed.





Biopsy

Once a polyp is found, it is removed,either by colonoscopy, flexiblesigmoidoscopy, or as part of asurgery. A pathologist closelyexamines the polyp cells - known asa biopsy sample -- under a

microscope in the laboratory todetermine whether the growth isbenign or malignant.



This small adenomatous polyp(tubular adenoma) on a small

stalk is seen microscopicallyto have more crowded,disorganized glands than thenormal underlying colonicmucosa. Goblet cells are less

numerous and the cells liningthe glands of the polyp havehyperchromatic nuclei.However, it is still well-differentiated andcircumscribed, without

invasion of the stalk, and isbenign



Prognosis

Adenomatous polyps: Can all potentially become malignant,

but actual risk per polyp is small.

Up to 50% of over 60 year olds havemore than one adenomatous polyp,but only 6 % of people develop bowel

cancer.

Risk of recurrence is great however if original polyps were >1cm, or morethan 4 polyps, or if dysplasia is shown.

Documents

Differential Diagnosis of Adenomas