Paraneoplastic Syndromes

Question 1

Prevelance of paraneoplastic sydrome with lung cancer

Answer 1

~ 2%

Question 2

9 cateogires of lung cancer related paraneoplastic syndrome

Answer 2

1. Hypercalcemia
2. SIADH
3. Cushing’s syndrome
4. Bone changes
5. Neuropathy
6. Myopathy
7. Anemia
8. Hypercoaguability
9. Dermatologic changes

Question 3

Characteristics of PNS (hypercalcemia)

Answer 3

• Metastatic bone lesions
• Elevated PTH (SCC)
• Incidence: 10% of lung cancer patients
• Sx: constipatin, anorexia, polydipsia, irritability

Question 4

Characteristics of PNS (SIADH)

Answer 4

• Associated with SCLC and women
• hyponatremia with elated U_Na
  
  • nausea, seizures, AMS
• Tx: fluid restriction +/- demeclocycline (AHD inhibion in kidney)

Question 5

Characteristics of PNS (Cushing’s syndrome)

Answer 5

• Associated with SCLC
• Autononmous ATCH production
  
  • No suppression with dexamethasone
• Sx: edema and muscle weakness

Question 6

Characteristics of PNS (bone changes)

Answer 6

• Clubbing (SCC)
• Hypertrophic pulmonary osteoarthropathy
  
  • radius, ulna, tibea, fibula
  • new bone formation and inflammation at edges of bone > pain
  • tx: NSAIDS

Question 7

Characteristics of PNS (neuropathy)

Answer 7

• common and multifactorial
• brain or neurologic mets vs. circulating antibodies
• neuropathies frequently preceed lung ca diagnosis

Question 8

Characteristics of PNS (myopathy)

Answer 8

• Proximal muscle weakness
  
  • Etiologic theories:
    
    • Weakness manifestation of myosistis
    • Defect in neuromuscular transmission
  • Eaton-Lambert syndrome
    
    • Assoc with SCLC
    • Ig against voltage-gated Ca channels (inhibits presynaptic Ach release)

Question 9

Eaton-Lambert syndrome

Answer 9

• Assoc with SCLC
• Ig against voltage-gated Ca channels (inhibits presynaptic Ach release)

Question 10

Characteristics of PNS (anemia)

Answer 10

• Common in lung ca
• Multifactorial cause:
  
  • decreased RBC life span
  • decreased Fe stores
  • decreased Fe binding capacity

Question 11

Characteristics of PNS (hypercoaguability)

Answer 11

• Common in lung cancer
• Associated with vascular thrombosis
  
  • Maybe resistent to anticoagulation
• Treatment of tumor may reverse hypercoaguble state

Question 12

Dermatologic PNS manifestation associated with lung cancer

Answer 12

• Dermatomyositis
• Erythema gyratum
• Lanunioa acquisita

Question 13

Dermatologic PNS manifestiations MC assocated with what lung cancer histologic subtype

Answer 13

Adenocarcinoma