BENEFICAL FOR M.L.T STUDENTS

1. GASTROINTESTINAL
TRACT {CYTOLOGY}

2. Topics
01. Anatomy,
histology,physiology. 02.
Collection of sample,
preparation of smears and
staining.
03. cytology of normal, non
malignant and malignant
conditions.

3. ANATOMY
#. It performs the mechanical & chemical
processes of digestion
absorptionof nutrients & elimination of wastes
.
# . It consists of parts are :
- mouth,
- esophagus,
- stomach,
- intestine,
- acessory organs .

5. HISTOLOGY
The GI tract is made up of three layers .
They are follows as:-
# outer mucosa,
# middle mucscular layer,
# inner mucosa.
The serosa is the outermost serous layer of the GI tract.
It ids formed by the peritoneum.
The middle muscular layer is made up of smooth muscles. It
consists of outer longitudinal and inner circular muscles layer.
The contraction of circular muscles causes narrowing of the
lumen and the contarction of longitudinal muscles causes
shortening of the gut.
The muscles fibers are electrically connected with one another
through a large number of gap junctions .
The bundle fuses with one another at many points and therfore
the muscle layer functions as syncytium .

6. HISTOLOGY OF THE GIT

7. PHYSIOLOGY OF GIT :

8. Collectin of sample , preparation
of smears and staining

12. Cont....
 Muscularis poropira : consist of
two muscualar layer and inner
circular layer and an outer
longitutinal layer.
 upper one third is composed of
straited muscle.
 striated smooth muscle bundles are mixed and
interwoven
in the middle third of eosghagus , the distal third
consist of only smooth muscle .

21. Gastrointestinal tract biopsy :
 PAS , AB-PAS and HID are used in the
evaluation of gastrointestinal biospies. They are
helpful in detecting intestinal metaplasia and
neoplasia .
Flexiable fiberoptic endoscopy biopsies and
small biopises are fixed in neutral buffered formalin
.
 intestinal metaplasaia : in stomach
predisposing to carcinoma secrets
sulfomucosubstances .
 large intestine : sialomucins and sulfomucins
of large intestine are reactive , whereas neutral

22. • Non malignant and malignant conditions :
Gastric Adenocarcinoma:
Can originate anywhere in the stomach
-  “ intestinal- type’’ 70-80% of gastric cancers , resembles
intestinal cancers with galsndular structure .
 “ diffuses ’’ 20-30% of gastric cancers , poorly differentiate d,
signet – ringed cells , lacks glandular strucutres .
# Affects women and men equally .
Risk factors
01 , smmoking .
02 , precinious anemia
03 , h/o partial gastric resection
signs and symptoms
ASYMPTOMATIC UNTIL LATE STAGES
 dyspesia and weight loss are most common presenting
symptoms
anorexia
 early satiety

23. LAB DIAGNOSIS :
 Iron deficiency anemia from blood loss or anemia of
chronic diesease .
 elevated LFTs if liver mets
 no specific tumors markers .
DIAGNOSTICS :
 upper endoscopy
Barium upper GI is acceptable if endoscopy is not
available , but no ability to distingusih benign from malignant
lesions and no abililty to bx
 once gastric ca is dx , CT and EUS (endoscopic ultra
sound ) are needed to see extent of tumor , possible mets
and nodal innvolment
 PET scan or PET-CT combo needed for distant ,mets…
GASTRIC LYMPHOMA :
Sx : dyspesia , weight loss , anemia .
 imaging on upper GI or endoscopy : thickened folds ,
ulcer mass, or infiltrating lesions .

24. OTHER GASTRIC CANCERS :
01 GASTRIC CARCINIOD TUMORS
02 GASTROINTESTINAL MESCENCHYMAL TUMORS
 derive from mesenchymal stem cells .
 generally incidental findings on imaging or
endosdcopy
surgery recommended .
MALIGNANCIES OF THE SMALL INTESTINE:
Adenocarcinoma : most commonly in the duodenum or proximal with
most common site of small intestine cancers is at ampula of vater .
Ampullary carcinom a : presceence of jaundice , obstruction , and
bleeding .
Carcionid tumors : slow growing neuroendocrine tumor.
Secrete hormones : serotonin , somatostain , gastrin and substance P
SMALL INTESTINE SACROMA : stromal tumors ( arise from smooth
muscle ) aka leiomyosacromas
KAPOSAI SARCOMA was once common with AIDS .

25. COLORECTAL CANCER
--> obesity
--> diabetes
--> tobaccoo
--> diet .
# high in animal fat and calories
# low in fiber .
COLORECTAL CANCER SCREENING :
# reduces mortality.
# CRC can prevented .
Screening options :
1. Annual fecal occual blood test (FOBT).
2. Flexiable sigmoidoscopy q5 years .
3. Colonoscopy qro years.
4. Double contrast barrium enema 95 years

27. COLORECTAL CANCER SCREENING :