PBL

Question 1

What is a teratoma?

Answer 1

A teratoma is a type of tumour with tissue or organ components resembling derivatives of the germ layers. Ectoderm is the most commonly represented layer so it is common to see ectoderm derivatives such as hair and teeth in a teratoma. They can be malignant or benign.

Question 2

How do teratomas originate?

Answer 2

They can be derived from:

- Germ cells
- Sperm/oocyte 
- Embryonal cells

Question 3

Discuss germ cell teratomas.

Answer 3

• usually found in the gonads (testes or ovary)
• rare
• thought to develop from germ cells that have failed to differentiate into sperm or oocytes
• cause is not totally understood
• some inherited factors have been associated with germ cell tumours including malformations of the CNS, genitourinary tract and major malformations of the lower spine
• cryptorchidism = increased risk of germ cell tumour

Question 4

What is cryptorchidism?

Answer 4

Failure of the testes to descend in to the scrotal sac

Question 5

Discuss Embryonal teratomas.

Answer 5

• normally found on the midline of the body

- usually congenital

Question 6

Compare malignant and benign tumours

Answer 6

• invasive/localised
• metastasise/well encapsulated
• fast growing/slow growing
• may not resemble tissue of origin/resembles tissue of origin
• damage at local or distant site/damage at local level
• features of dysplasia/regular nuclei

Question 7

What changes occur in a cell to give rise to cancer?

Answer 7

• Unregulated cell proliferation
  
  • Increased growth capability
  • Blocked differentiation
  • Increased cell motility
  • Acquired tissue invasion capability
  • Loss of genomic stability