9th January 2024

Paraneoplastic

Some types of lung cancers are associated with particular paraneoplastic syndromes.

• Syndrome of Inappropriate Antidiuretic Hormone secretion (SIADH)
  • Associated with SCLC. The increased production of ADH causes hyponatraemia, which can result in numerous symptoms, from nausea and vomiting to seizures and coma.
• Lambert-Eaton Myasthenic Syndrome (LEMS)
  • Regarded as an autoimmune disorder associated with SCLC, LEMS is a condition in which antibodies target voltage-gated calcium channels, causing widespread weakness. Largely affecting the lower limbs, it can also lead to weakness of ocular muscles and muscles of respiration, leading to ophthalmoplegia and respiratory failure, respectively.
• Dermatomyositis
  • Heliotropic rash, Gottron’s papules and proximal myopathy
• Hypertrophic Pulmonary Osteoarthropathy (HPO)
  • Associated with nail clubbing, periostitis and arthropathy of the long bones of the limbs
• Cushing syndrome
  • Associated with SCLC, this condition has many features, including weight gain associated with typical facies and dorsocervical fat pad, hirsutism, hypertension, diabetes mellitus, hypernatraemia and hypokalaemia, oligo/amenorrhoea, impotence and osteoporosis.
• Hypercalcaemia secondary to PTH-related protein (PTHrP)