Part two - oncology

Question 1

What is Stewart-Treve’s syndrome

Answer 1

Chronic lymphoedema-associated angiosarcoma usually as a result of breast cancer treatment

Question 2

Distribution of soft-tissue sarcomas

Answer 2

Lower limb and girdle 40%
Upper limb and girdle 20%
Retroperitoneum and intraperitoneal sites 20% (includes GISTs)
Trunk 10%
Head and neck 10%

Question 3

What are sarcomas?

Answer 3

A rare and heterogeneous group of malignant tumors of mesenchymal origin

1% percent of all adult malignancies
~50 tumour subtypes named according to tissue most closely resemble

Question 4

Cancers curable with radiotherapy

Answer 4

• Head & neck cancers
  
  • Cervical cancer
  • Seminomas
  • Hodgkin’s and non-Hodgkin’s lymphoma
  • Bladder cancer
  • Early lung cancer
  • Anal and skin cancer
  • Medulloblastoma and other brain tumours
  • Thyroid cancer

Question 5

Distribution of sarcoma

Answer 5

40% lower limb and girdle
20% upper limb and girdle
20% retro- and intra-peritoneal including GIST
10% trunk
10% head and neck

Question 6

What is a GIST?

Answer 6

Gastro-intestinal stromal tumour

Most common mesenchymal tumour of the GIT accounting for up to 2% of all GI malignancies

Question 7

What are the neural tumours of the GI tract?

Answer 7

PERIPHERAL NERVE
* Schwannoma
* Neurofibroma
* Neuroma
* Malignant peripheral nerve sheath tumour
SYMPATHETIC OR CHROMAFFIN SYSTEM
* Neuroblastoma
* Ganglioneuroma
* Paraganglioma (glomus tumour)
* Carcinoids
GASTROINTESTINAL PLEXUS
* GIST

Question 8

What is a carcinoid tumour?

Answer 8

Well-differentiated neuroendocrine tumours originating in the digestive tract, lungs or rare primary sites such as the kidneys or ovaries.

Generally not used to describe rare high-grade or poorly differentiated NETs

Those arising in the pancreas and duodenum are referred to as pancreatic neuroendocrine (islet cell) tumours

Question 9

What is carcinoid syndrome?

Answer 9

A constellation of symptoms mediated by various humoural factors that are elaborated by some carcinoid tumours.

Typically refers to flushing and diarrhoea which occurs predominantly with metastatic carcinoid tumours originating from the small intestine

Question 10

Distribution of carcinoids

Answer 10

Gastrointestinal tract - 55%
      * Small intestine especially ileum - 45%
      * Rectum - 20%
      * Appendix - 15%
      * Colon - 10%
      * Stomach - 10%
Broncho-pulmonary system - 30%
Other - 15%

Question 11

How are carcinoids classified?

Answer 11

By embryonic divisions

  * Foregut - stomach, lung
  * Midgut - Jejuno-ileal, appendix - produce serotonin and other vasoactive substances giving rise to the typical carcinoid syndrome
  * Hindgut - colon, rectum, genitourinary - rarely associated with a hormonal syndrome
  * Ovary

By specific primary site - probably more helpful as specific primary sites posses their own unique clinical characteristics

Question 12

What is carcinoid syndrome?

Answer 12

A constellation of symptoms mediated by various humoural factors that are elaborated by some carcinoid tumours.

Typically refers to flushing and diarrhoea which occurs predominantly with metastatic carcinoid tumours originating from the small intestine

Question 13

Distribution of carcinoids

Answer 13

Gastrointestinal tract - 55%
      * Small intestine especially ileum - 45%
      * Rectum - 20%
      * Appendix - 15%
      * Colon - 10%
      * Stomach - 10%
Broncho-pulmonary system - 30%
Other - 15%

Question 14

How are carcinoids classified?

Answer 14

By embryonic divisions

  * Foregut - stomach, lung
  * Midgut - Jejuno-ileal, appendix - produce serotonin and other vasoactive substances giving rise to the typical carcinoid syndrome
  * Hindgut - colon, rectum, genitourinary - rarely associated with a hormonal syndrome
  * Ovary

By specific primary site - probably more helpful as specific primary sites posses their own unique clinical characteristics

Question 15

Aetiology and risk factors for sarcoma

Answer 15

Majority sporadic with risk factors of:

• Viral infections and leiomyosarcoma (EBV in AIDS)
• Radiation
• Chronic lymphoedema -> Stewart-Treves syndrome
• Trauma
• Chemical exposure

Genetic disorders

• NF1 - 10% risk of peripheral-nerve sheath tumours
• Hereditary retinoblastoma (RB1) and sarcoma
• Li-Fraumeni syndrome

HI CLIT = hereditary, irradiation, chemical, lymphoedema, infection, trauma

Question 16

What are the most common sarcomas?

Answer 16

Liposarcoma
Leiomyosarcoma
Malignant fibrous histiocytoma

Question 17

Most common histologic subtypes of sarcomas based on location in adults

Answer 17

Retroperitoneal and intra-abdo - lipo- and leiomyosarcoma
Visceral - GIST, leiomyosarcoma
Extremity - liposarcoma and malignant fibrous histiocytoma

Question 18

How does sarcoma spread

Answer 18

Haematogenously with extremities to lung and retroperitoneum to liver

Lymph node metastases in up to 5% only

Question 19

When do you suspect sarcoma?

Answer 19

Any enlarging mass larger than 5cm or new mass persisting beyond four weeks

Question 20

Tell me about retroperitoneal/intra-abdominal soft-tissue sarcomas

Answer 20

Liposarcoma (55%), leiomyosarcoma (25%)

Present with:

     * 80% mass
     * 40% neurological symptoms in lower limbs
     * 40% pain

Usually >10cm at presentation

Leimyosarcoma may secrete insulin-like growth factor -> hypoglycaemia

Question 21

How are soft-tissue sarcomas staged?

Answer 21

TNM
Size - T1 < 5cm, T2 > 5cm
Relation to fascia - superficial (a) or deep (b)
Grade - well, moderately, poorly, undifferentiated
Nodal metastases - N0 or N1
Distant metastases - M0 or M1

All grade 3 and 4 are at least stage II
All nodal and distant mets are stage IV

For retroperitoneal tumours use:
Grade
Completeness of resection
Presence of metastases

Question 22

Prognosis of soft-tissue sarcoma

Answer 22

Five-year survival:
Stage I    = 90%
Stage II   = 70%
Stage III  = 50%
Stage IV = 10-20%

Question 23

Immunohistochemstry staining for GIST

Answer 23

Positive:

• CD117 - >95%
• CD34 - 60%

Negative:

• S100
• Desmin