experiences of specimen dissection

Case Study: Colorectal Cancer

Rebecca MungallMumin Abla

The University of the West of ScotlandApplied Biomedical Science BSc Students

Colorectal Cancer: An IntroductionColorectal cancer, a cancer of the colon or rectum, is the third most common cancer in the UK, with the second highest fatality rate of all cancers.

(Fig.1: Anatomy of the Large Intestine)KEY: 1: Cecum; 2: Ascending Colon; 3: Right Hepatic Flexure; 4: Transverse Colon; 5: Left Hepatic Flexure; 6: Descending Colon; 7: Sigmoid Colon; 8: Rectum.

Risk FactorsRisk factors associated with developing colorectal cancer can be divided into 2 main categories; modifiable and uncontrollable .

Preventable Risk Factors:

•Diet•Alcohol consumption•Smoking•BMI

Non Preventable Risk Factors

•Genetic/hereditary conditions(FAP, HNPCC)Family history of colorectal cancer•Presence of certain medical conditions (Crohn’s/ulcerative colitis)•Previous cancer diagnosis

Signs and Symptoms

Colorectal cancer may present with symptoms such as:

• A change in bowel habits

• Rectal bleeding or blood in stool

• Persistent abdominal discomfort

• Anemia

• Increased infections

Early stage, asymptomatic colorectal cancers are

Often detected during the bowel screening program..

Treatment Plan and Monitoring

Treatment:

• Surgery

• Chemotherapy

• Radiotherapy

Monitoring:• Medical history and physical

examinations• Regular colonoscopies• Imaging tests• Blood tests for tumor markers

Case Study – Haematology

Parameter Result Units Ref. Range

Hb 10.6 (LOW)

g/dL (13.5-18.0)

HCT 0.342(LOW)

L/L (0.370-0.470)

RDW 17.6 (HIGH)

% (11.0-16.0)

MCH 26.9 (LOW)

pg (27.0-32.0)

(XN10 Automated Haematology Analyser)

Haematology: Blood Film

Poikilocytosis

Anicytosis

Hypochromic cells

Elliptocytosis

Case Study: Pathology

• The patient underwent a colonoscopy, with biopsies, on 10/11/2014

• Biopsy analysis: Moderately differentiated adenocarcinoma, primary origin.

Sigmoid Colon Excision

Normal Section vs Tumour Section

Invasion

Lymph Node Analysis

Normal Lymph Node Metastatic lymph Node

Immunocytochemistry

CK 20 POSITIVE CK 7 NEGATIVE

Immunocytochemistry

CDX-2 POSITIVE CEA POSITIVE

Immunocytochemistry

TTF-1 negative Positive control

Immunocytochemistry

CA 125 NEGATIVE POSTIVE CONTROL

Staging

Case Study: Microbiology

Signs of sepsis:

• High temperature

• Lowered blood pressure (septic shock)

• Tachycardia

• Organ failure (Gram negatives)

Send specimens to Microbiology

laboratory for blood culture analysis.

Blood Culture Analysis

• Continuous Monitoring• Easy to use• Reliable• Fully automated

BactAlert Analyser

CO2 + H2O ↔ H2CO3 ↔ HCO3- + H+

Gram Stain

Gram Positive Blood Culture Gram Negative Blood Culture

Culture

• Faecal Streptococci; e.gStrep. gallolyticus Enterococci spp

• Aerobic and anaerobic species; e.g. E. coli, B. fragilis

Antimicrobial Susceptibility

Identification: MALDI-TOF

Sepsis: Clinical Significance

• Organ failure (Gram negatives)

• Coma

• Respiratory Problems: Ventilation

• Increased risk of contracting additional infections due to intravenous lines etc.

• Broad-spectrum antibiotics: More susceptible to resistant ‘superbugs’ such as C.difficile

• Potentially fatal

Case Study: Biochemistry

• Blood sample taken into a gold top, Serum Separator Tube containing gel to allow serum separation.

• Tests requested:

❖ CEA

❖CA125

❖CRP

❖LFT

CEA – Carcinoembryonic Antigen

• Monomeric Glycoprotein

• found in GI tract

• Tumour marker measured in biochemistry

• detect residual disease

• monitor chemotherapy after CRC

First Reaction

Sample R2

(Ruthenium Labelled Antibody)R1/Biotinylated

Antibody

9 Minute incubation

Sample R1/R2 Mixture

Second Reaction

Sample R1/R2 Mixture Streptavidin-coated Microparticle

9 Minute incubation

Complex bound to micro-particles via interaction of

biotin and streptavidin

Second Reaction Continued

Signal

(Light)

Conc.

Calculation of Result

(μg/L)

Patient CEA Results

Conclusion• CRC is still the leading cause of death

• Current screening techniques: (Colonoscopy, FS, FOBT)

• Fecal Molecular Marker

• Vaccines?

Thank you for listening

Please feel free to ask any questions at this point.

With thanks to all of the staff at Wishaw General Hospital, especially our training officers, for all of their help and for giving us this opportunity.