Tuberous sclerosis

Tuberous sclerosis, also tuberous sclerosis complex (abbreviated TSC), is an autosomal dominant syndrome associated with an increased risk of hamartomas and some risk increase for malignant tumours.

Historically described as:

1. Epilepsy.
2. Mental retardation.
3. Adenoma sebaceum (angiofibromas).

General

• Autosomal dominant with variable penetrance.
• Majority (60-70%) are de novo mutations.

Associations

Pathologic:

• Renal angiomyolipoma.
  • Seen in approximately 85% of individuals with TSC.
• Cardiac rhabdomyoma.
• Lymphangiomyomatosis - seen in ~1/3 of females.
• Subependymal giant cell astrocytoma (SEGA).
• Renal cysts.
• Tuberous sclerosis-associated renal cell carcinoma - an evolving entity.

Note:

• The same genes (TSC1, TSC2) are implicated in PEComas.

Mnemonic SALSA HEART:

• Shagreen patches.
  • Shagreen patch = connective-tissue nevus composed of collagen, i.e. collagenoma.
• Ash Leaf spots.
• SEGA.
• Angiofibroma.
• Hamartomas.
• Epilepsy.
• Angiomyolipoma.
• Rhabdomyoma.
• Tubers.

Genes

• TSC1.
• TSC2.
  • Some evidence to suggest it is more often implicated in malignant tumours (than TSC1).
  • TSC2 mutations have a higher prevalence (than TSC1 mutations) and are considered more aggressive.

Incidence

~1 in 10,000 population.

See also

• Adrenal gland.
• Kidney tumours.
• Neurocutaneous syndromes.
• PEComa.