Derm Cases · Dermatology / Paediatrics / Neurocutaneous
OSCE — ash-leaf macules and angiofibromas: TSC criteria, vigabatrin, mTOR inhibitors
An 8-minute OSCE on TSC cutaneous tetrad, 2012/2021 diagnostic criteria concepts, infantile spasms with vigabatrin, SEGA/AML surveillance, and everolimus/topical sirolimus.
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NEET-PGINICETUSMLEPLABMRCP
Prompt
An 8-minute OSCE on TSC cutaneous tetrad, 2012/2021 diagnostic criteria concepts, infantile spasms with vigabatrin, SEGA/AML surveillance, and everolimus/topical sirolimus.
Brief (to candidate)
An 18-month-old has hypopigmented ash-leaf macules and new clusters of facial red papules; parents report flexor spasms. You have 8 minutes to diagnose TSC, apply criteria thinking, start seizure pathway, and outline organ surveillance and mTOR therapy principles.
[2]Candidate instructions
- Name the cutaneous tetrad and gene pathway (TSC1/TSC2–mTOR).
- Apply major/minor diagnostic criteria concepts (clinical definite TSC).
- Manage infantile spasms first-line in TSC.
- Outline SEGA, cardiac rhabdomyoma, renal AML, LAM surveillance triggers.
- State roles of everolimus and topical sirolimus.
Examiner checklist (mark each domain / 10)
| Domain | Key actions expected |
|---|---|
| Cutaneous tetrad | Ash-leaf (hypomelanotic) macules, facial angiofibromas (adenoma sebaceum), shagreen patch, ungual fibromas (Koenen); also confetti lesions, fibrous cephalic plaque[1][2] |
| Genetics / mechanism | TSC1 hamartin / TSC2 tuberin → mTORC1 hyperactivation → multi-organ hamartomas; AD ± de novo; TSC2 often more severe; TSC2-PKD1 contiguous gene → polycystic kidneys[1] |
| Diagnosis | International criteria: definite TSC by genetics or clinical major/minor combinations (2012 updated 2021 surveillance recommendations)[2][3] |
| Infantile spasms | West syndrome common; vigabatrin first-line in TSC-associated infantile spasms; EEG/MRI; neurology co-management |
| mTOR therapy | Systemic everolimus for growing SEGA, enlarging AML, refractory seizures (selected); topical rapamycin/sirolimus for facial angiofibromas; oral sirolimus for LAM phenotype in women[5][7][8][9] |
| Surveillance red flags | SEGA obstructive hydrocephalus emergency; Wunderlich haemorrhage from AML; pneumothorax in LAM; avoid mTOR teratogenicity counselling in pregnancy planning |
| Communication | Lifelong MDT (derm, neuro, nephrology, cardiology, pulmonology); TAND behavioural spectrum |
Model key actions
- Recognise tetrad and confirm TSC with criteria/genetics pathway.[2]
- Treat TSC infantile spasms with vigabatrin as preferred first-line.[2]
- Use everolimus for SEGA/AML indications and topical sirolimus for angiofibromas.[5][9]
Common errors
- Calling ash-leaf macules “vitiligo” without Woods lamp/neurocutaneous exam.
- Using non-vigabatrin first-line for TSC spasms without justification.
- Missing renal AML / SEGA surveillance.
- Prescribing systemic mTOR without indication or pregnancy counselling.
References7ShowHide
- [1]Henske EP, Jóźwiak S, Kingswood JC, et al. Tuberous sclerosis complex. Nat Rev Dis Primers, 2016.PMID 27226234
- [2]Northrup H, et al. Updated International TSC Diagnostic Criteria and Surveillance/Management Recommendations. Pediatr Neurol, 2021.PMID 34399110
- [3]Northrup H, Krueger DA. Tuberous sclerosis complex diagnostic criteria update: recommendations of the 2012 International TSC Consensus Conference. Pediatr Neurol, 2013.PMID 24053982
- [5]Franz DN, et al. Efficacy and safety of everolimus for subependymal giant cell astrocytomas associated with tuberous sclerosis complex (EXIST-1). Lancet, 2013.PMID 23158522
- [7]Bissler JJ, et al. Everolimus for angiomyolipoma associated with tuberous sclerosis complex or sporadic lymphangioleiomyomatosis (EXIST-2). Lancet, 2013.PMID 23312829
- [8]McCormack FX, et al. Efficacy and safety of sirolimus in lymphangioleiomyomatosis. N Engl J Med, 2011.PMID 21410393
- [9]Koenig MK, Bell CS, Hebert AA, et al. Efficacy and Safety of Topical Rapamycin in Patients With Facial Angiofibromas. JAMA Dermatol, 2018.PMID 29800048