Cellular pathology

Question 1

Fixation of specimen

• Product used for fixing
• Exceptions

Answer 1

Uses 10% neutral buffered formalin

Except: frozen specimen, cytology.

Question 2

Process of tissue handling and processing (4)

Answer 2

1. Fixation of specimen
   - Done using formalin
   - Except: frozen sample, cytology.
2. Cutting of specimen
3. Staining
   - H+E for all
   - Special stains to look for specific structures
4. Immunohistochemistry
   - Monoclonal antibodies used to identify specific proteins in tissues.

Question 3

Neoplasia cytology features (5)

Answer 3

Increased nucleus: cytoplasm ratio.

Irregular nuclear margin.

Atypical mitosis

Irregular distribution and texture of chromatin

Hyperchromasia

Question 4

Cytokeratins

Answer 4

Proteins found in intracytoplasmic cytoskeleton of epithelial tissue.

• Component of intermediate filaments
• Specific cytokeratin expressed differently in specific tissue

Question 5

CK 20 expression

Answer 5

Cytokeratin type expressed in (CK 20 positive):

• Upper GI ( Adenocarcinoma)
• Colorectal
• Merkel cell
• Urothelial
• Pancreatic (ductal)

Question 6

CK 7 expression

Answer 6

CK 7 positive

• Upper GI (adenocarcinoma)
• Ovarian
• Pancreatic (ductal)
• Pulmonary (adenocarcinoma)
• Endometrial
• Thyroid.

Question 7

CK 7 negative epithelium

Answer 7

Colorectal
Merkel cell

Prostatic
Hepatocelullar
Renal cell
Adrenal cortical

Question 8

CK 20 negative epithelium

Answer 8

Breast
Ovarian
Pulmonary (adenocacarcinoma)
Endometrial
Thyroid

Prostatic
Hepatocellular
Renal cell
Adrenal cortical

Question 9

Prognostic biomarkers

• Breast
• Ovary
• Colon
• NSCLC (non-small cell lung cancer)

Answer 9

Breast

• BRCA1
• Her-2/ neu

Ovary
- BRCA1

Colon
- High frequency MSI = better prognosis

NSCLC

• K-ras = worse prognosis
• EGFR = worse prognosis

Question 10

Predictive biomarkers

Answer 10

Breast, gastric
- Her-2/ neu

NSCLCC
- K-ras, p53