Simplify this to me , radiology pg resident
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python3 - << 'EOF' from pptx import Presentation prs = Presentation("/tmp/workspace/attachments/461742e3-6931-48bd-8c28-042e987dd338/Phakomatoses by Sahithi.pptx") for i, slide in enumerate(prs.slides, 1): print(f"\n=== SLIDE {i} ===") for shape in slide.shapes: if shape.has_text_frame and shape.text_frame.text.strip(): print(shape.text_frame.text) EOF
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Phakomatoses (Neurocutaneous Syndromes) - Radiology Simplified
Core concept: Phakomatoses = congenital disorders of neuroectoderm origin. They hit CNS + skin + other organs. Think: hamartomas and tumors in weird places.
1. NEUROFIBROMATOSIS TYPE 1 (NF1) - "Von Recklinghausen"
Gene: Chr 17q11.2 - Neurofibromin (tumor suppressor). Loss → RAS pathway goes unchecked → tumors.
Diagnose with ≥2 of these:
| Feature | Threshold |
|---|---|
| Café-au-lait spots | ≥6 (>5mm pre-puberty, >15mm post-puberty) |
| Axillary/inguinal freckling | Present |
| Neurofibromas | ≥2 cutaneous OR ≥1 plexiform |
| Optic nerve glioma | Present |
| Lisch nodules (iris hamartomas) | ≥2 |
| Sphenoid wing dysplasia / tibial bowing | Present |
| First-degree relative with NF1 | Present |
Key Radiology:
Neurofibromas (cutaneous/subcutaneous)
- T1 hypo, T2 hyper, variable enhancement
- "Target sign" = central T2 low + peripheral T2 high (classic NF1)
Plexiform Neurofibromas
- "Bag of worms" appearance on MRI
- Multinodular, multiple target signs
- ⚠️ Risk of MPNST (malignant transformation)
Optic Pathway Glioma (most common CNS tumor in NF1)
- Fusiform enlargement of optic nerve
- T1 hypo, T2 hyper, variable enhancement
- Extends to chiasm
FASI (Focal Areas of Signal Intensity)
- T2/FLAIR bright, NO enhancement
- Basal ganglia, deep WM, corpus callosum
- Represent myelin vacuolization - regress with age
- Not tumors, don't panic
Sphenoid Wing Dysplasia
- Absent/hypoplastic sphenoid wing on CT
- Enlarged orbital fissure, pulsatile proptosis
- J-shaped sella, lambdoid defects also seen
Skeletal: Posterior vertebral scalloping, tibial pseudoarthrosis, scoliosis, dural ectasia, ribbon ribs
Thoracic: Lateral thoracic meningocele (convex side of scoliosis), mediastinal neurofibromas, lung interstitial fibrosis (lower) + bullae (upper)
MPNST (Malignant Peripheral Nerve Sheath Tumor)
- Heterogeneous mass, peripheral enhancement, perilesional edema, cystic areas, ill-defined margins
2. NEUROFIBROMATOSIS TYPE 2 (NF2)
Gene: Chr 22q12 (Merlin protein). Autosomal dominant.
Diagnose with:
- Bilateral vestibular schwannomas (pathognomonic) OR
- Family history + unilateral vestibular schwannoma OR
- Family history + any 2 of: meningioma, glioma, schwannoma, neurofibroma, juvenile posterior capsular lens opacities
Key Radiology:
Vestibular Schwannomas (bilateral = hallmark)
- CP angle mass with IAC widening
- T1 iso/hypo, T2 hyper
- Homogeneous enhancement (heterogeneous if necrotic/cystic)
- "Ice-cream cone" appearance at IAC
Meningiomas (2nd most common)
- Multiple dural-based enhancing lesions
- Bilateral schwannomas + meningiomas = NF2 until proven otherwise
Ependymomas
- Intramedullary, cervical cord or cervicomedullary junction
- Up to 53% of NF2 patients
- T1 iso/slightly hyper, T2 hyper, homogeneous enhancement
3. TUBEROUS SCLEROSIS COMPLEX (TSC)
Genes: TSC1 (Chr 9q34, hamartin) or TSC2 (Chr 16p13.3, tuberin). Autosomal dominant. Loss → mTOR pathway goes unchecked → hamartomas everywhere.
Key Radiology by Organ:
Brain - 4 key lesions:
| Lesion | Location | CT | MRI | Enhancement |
|---|---|---|---|---|
| Cortical tubers | Widened gyri (frontal mainly) | Hypodense | T2 bright, T1 dark | No |
| Subependymal nodules (SEN) | Along lateral ventricles, near foramen of Monro | Hyperdense, calcify progressively | T1 bright, SWI blooming | Variable |
| SEGA | AT foramen of Monro | Calcifications | Mixed solid-cystic, heterogeneous, T1+T2 mixed | Intense |
| Radial migration lines | Subependymal → cortex | - | T2/FLAIR bright linear bands | No |
SEN vs SEGA - Critical distinction:
- SEN = stable, no hydrocephalus, small
- SEGA = growing on serial imaging, causes obstructive hydrocephalus, larger - this one needs surgery/mTOR inhibitors
Kidneys:
- Angiomyolipoma (AML) - 70-80% of TSC patients
- CT: macroscopic fat (< -20 HU), hypervascular
- US: hyperechoic
- MRI: T1 bright, drops on fat-sat
- Complication: hemorrhage (treat if >4cm)
Lungs:
- LAM (Lymphangioleiomyomatosis) - adult females predominantly
- HRCT: multiple thin-walled cysts uniformly distributed, normal intervening lung
- Complications: pneumothorax, chylous effusion
Heart:
- Cardiac rhabdomyoma - most common cardiac tumor in infancy
- Echo: multiple echogenic intramyocardial masses
- Usually regresses spontaneously (wait and watch)
Others: Hepatic AMLs, retinal hamartomas, sclerotic bone lesions, dental pits, gingival fibromas
4. VON HIPPEL-LINDAU (VHL)
Gene: Chr 3p25-26 (pVHL). Autosomal dominant. Loss → HIF-α accumulates → VEGF↑ → highly vascular tumors.
Key Radiology by organ:
CNS Hemangioblastomas (most characteristic)
- Sites: cerebellum > spinal cord > brainstem
- Cyst + enhancing mural nodule = classic
- T1 iso/hypo, T2 hyper, intense mural nodule enhancement
- Look for flow voids (vascular tumor)
Retinal Hemangioblastoma
- Earliest manifestation of VHL
- Diagnosed by fundoscopy, not MRI
Clear Cell Renal Cell Carcinoma (most common cause of death in VHL)
- CT: bilateral, multiple, hypervascular enhancing masses
- MRI: T1 hypo, T2 hyper, early enhancement
Pheochromocytoma (10-20%)
- MRI: T2 markedly hyperintense = "light bulb sign"
- Intense enhancement
- Clinically: episodic HTN, headache, sweating, palpitations
Pancreatic lesions: Simple cysts, serous cystadenomas, pNETs
Endolymphatic Sac Tumor
- CT: destructive lesion of posterior petrous bone
- MRI: heterogeneous T1+T2, intense enhancement, intralesional hemorrhage
- Presents with: hearing loss, vertigo, tinnitus
5. STURGE-WEBER SYNDROME (SWS)
Gene: Somatic GNAQ mutation (not inherited). Sporadic.
Classic triad: Port-wine stain (face, V1 distribution) + leptomeningeal angiomatosis + ocular vascular abnormalities
Key Radiology:
CT findings:
- Tram-track (gyriform) calcifications = cortical + subcortical calcification following gyral pattern
- Cerebral atrophy (ipsilateral)
- Enlarged ipsilateral ventricle + choroid plexus
- Calvarial thickening (chronic)
MRI findings:
- Leptomeningeal (pial) enhancement (parieto-occipital most common)
- Ipsilateral cerebral atrophy
- Enlarged ipsilateral choroid plexus
- Dilated deep medullary veins
- SWI/GRE: abnormal venous vasculature
Mechanism: Chronic venous hypertension → cerebral ischemia → atrophy + calcification
6. OTHER SYNDROMES (Quick Reference)
| Syndrome | Key Gene | Hallmark Imaging Finding |
|---|---|---|
| Ataxia Telangiectasia | ATM gene (AR) | Progressive cerebellar atrophy, vermis early; T2 WM hyperintensities; capillary telangiectasias on SWI |
| Parry-Romberg | Sporadic | Progressive hemifacial atrophy - skin, soft tissue, bone |
| Gorlin-Goltz (Basal Cell Nevus) | PTCH1 | Falx calcification, odontogenic keratocysts, bifid ribs; medulloblastoma risk |
| PHACES | Sporadic (F>M) | Posterior fossa malformations + facial hemangioma + arterial anomalies + coarctation + eye defects + sternal defects |
| Incontinentia Pigmenti | X-linked | Brain infarction, cerebral atrophy, corpus callosum hypoplasia, T2 WM hyperintensities |
| Cowden Syndrome | PTEN | Lhermitte-Duclos disease (cerebellar "tiger-striped" T2 lesion with folial thickening) + breast/thyroid/endometrial cancer risk |
HIGH-YIELD EXAM PEARLS
| Finding | Diagnosis |
|---|---|
| Bilateral vestibular schwannomas | NF2 |
| Target sign on T2 MRI | NF1 neurofibromas |
| Cyst + enhancing mural nodule in cerebellum | VHL hemangioblastoma |
| Tram-track cortical calcifications | Sturge-Weber |
| SEGA at foramen of Monro + obstructive hydrocephalus | TSC |
| T2 "light bulb sign" in adrenal | VHL pheochromocytoma |
| Macroscopic fat in renal mass | Angiomyolipoma (TSC) |
| LAM (thin-walled cysts, adult female) | TSC |
| "Tiger-striped" cerebellar T2 lesion | Cowden/Lhermitte-Duclos |
| Bag-of-worms infiltrative lesion | Plexiform neurofibroma (NF1) |
| Falx calcification + odontogenic cysts | Gorlin-Goltz |
Quick memory hook: NF1 = 17q, NF2 = 22q, TSC = 9q/16p, VHL = 3p, SWS = GNAQ (somatic)
Try again
Asking for Preferences
Got it - slide-by-slide, quick recall only. Here you go:
Phakomatoses - Slide by Slide (Quick Recall)
Slide 1 - Title
Phakomatoses = Neurocutaneous Syndromes. By Dr. Sahithi, JR2.
Slide 2 - Intro
- Congenital disorders of neuroectoderm
- Hit: CNS, skin, nerves, other organs
- Big 5: NF1, NF2, TSC, Sturge-Weber, VHL
Slide 3 - NF1 Title slide
Slide 4 - NF1 Genetics
- Chr 17q11.2 → Neurofibromin loss → RAS unchecked → tumors
- AD. Also called Von Recklinghausen disease.
Slide 5 - NF1 Diagnosis
Need ≥2 of:
- ≥6 café-au-lait spots
- Axillary/inguinal freckling
- ≥2 neurofibromas or ≥1 plexiform
- Optic nerve glioma
- ≥2 Lisch nodules
- Sphenoid wing dysplasia / tibial bowing
- 1st-degree relative with NF1
Slide 6 - NF1 Skin
- Café-au-lait = earliest sign, uniform light-brown macules
- Axillary freckling = Crowe's sign
- Lisch nodules = melanocytic iris hamartomas (slit lamp)
Slide 7 - Cutaneous Neurofibromas
- Benign peripheral nerve sheath tumors
- MRI: T1 ↓, T2 ↑, variable enhancement
- Target sign = central T2 low + peripheral T2 high ✔️
Slide 8 - Plexiform Neurofibromas
- "Bag of worms" appearance
- Multinodular, multiple target signs
- ⚠️ Can → MPNST (malignant transformation)
Slide 9 - Optic Pathway Glioma
- Most common CNS tumor in NF1
- Fusiform enlargement of optic nerve ± chiasm
- MRI: T1 ↓, T2 ↑, variable enhancement
Slide 10 - FASI
- Focal Areas of Signal Intensity = NOT tumors
- T2/FLAIR bright, no enhancement, no mass effect
- Basal ganglia, deep WM, corpus callosum
- Myelin vacuolization → regress with age
Slide 11 - Sphenoid Wing Dysplasia
- CT: absent/hypoplastic sphenoid wing, enlarged orbital fissure, pulsatile proptosis
- Also: J-shaped sella, lambdoid defects, Moyamoya
Slide 12 - NF1 Skeletal
Key findings to recall:
- Posterior vertebral scalloping
- Tibial pseudoarthrosis (classic)
- Kyphoscoliosis
- Dural ectasia
- Ribbon ribs
Slide 13 - Skeletal Images
- Posterior vertebral scalloping + tibial bowing with pseudoarthrosis
Slide 14 - NF1 Thoracic & Vascular
- Lateral thoracic meningocele (convex side of scoliosis)
- Lung: lower zone fibrosis + upper zone bullae
- Vascular: aneurysms, renal artery stenosis, coarctation
Slide 15 - NF1 Malignancies
- MPNST = malignant plexiform neurofibroma. MRI: heterogeneous, peripheral enhancement, perilesional edema, cystic change, ill-defined
- Others: breast Ca, gliomas, GIST, rhabdomyosarcoma
Slide 16 - NF2 Title
Slide 17 - NF2 Genetics & Diagnosis
- Chr 22q12 (Merlin). AD.
- Diagnose with bilateral vestibular schwannomas OR family history + unilateral schwannoma OR family history + any 2 of: meningioma, glioma, schwannoma, neurofibroma, lens opacity
Slide 18 - NF2 Schwannomas
- Most common tumors in NF2
- Most often: vestibular nerve > trigeminal > oculomotor
- MRI: CP angle mass, IAC widening, T1 iso/↓, T2 ↑, homogeneous enhancement
Slide 19 - Meningiomas + Bilateral Vestibular Schwannomas
- Bilateral schwannomas + multiple meningiomas = imaging hallmark of NF2
- "Ice-cream cone" at IAC
- Meningiomas = 2nd most common tumor in NF2
Slide 20 - NF2 Ependymomas
- Up to 53% of NF2 patients
- Cervical cord / cervicomedullary junction (intramedullary)
- MRI: T1 iso/slightly ↑, T2 ↑, homogeneous enhancement
Slide 21 - TSC Title
Slide 22 - TSC Pathophysiology
- TSC1 (Chr 9q34, hamartin) or TSC2 (Chr 16p13.3, tuberin). AD.
- Loss → mTOR pathway unchecked → hamartomas everywhere
Slide 23 - Cortical Tubers
- Most common brain lesion in TSC
- Widened gyri, frontal predominance
- CT: hypodense. MRI: T2 ↑, T1 ↓. No enhancement.
Slide 24 - Subependymal Nodules (SEN)
- Along lateral ventricles, near foramen of Monro
- CT: hyperdense, progressively calcify
- MRI: T1 ↑, SWI blooming
- Stable size = benign. Growing = think SEGA
Slide 25 - SEGA
- Site: foramen of Monro (obstructs CSF!)
- Mixed solid-cystic, T1+T2 heterogeneous, intense enhancement, calcifications
- Causes obstructive hydrocephalus → treat (surgery or mTOR inhibitor)
Slide 26 - SEN vs SEGA
| SEN | SEGA | |
|---|---|---|
| Size | Stable | Growing ✔️ |
| Hydrocephalus | No | Yes ✔️ |
| Enhancement | Variable | Intense |
SEGA = the only TSC brain lesion that grows
Slide 27 - Radial Migration Lines
- Connect subependymal nodules → cortical tubers
- T2/FLAIR bright linear bands
- Highly characteristic of TSC
Slide 28 - AML (Kidney)
- 70-80% of TSC patients
- CT: macroscopic fat (< -20 HU), hypervascular
- US: hyperechoic
- MRI: T1 ↑, drops on fat sat
- ⚠️ Hemorrhage risk if >4 cm
Slide 29 - LAM (Lung)
- Adult females
- HRCT: multiple uniform thin-walled cysts, normal intervening lung
- Complications: pneumothorax, chylous effusion
Slide 30 - Other TSC Findings
- Heart: cardiac rhabdomyoma (most common cardiac tumor in infancy) → usually regresses spontaneously
- Liver: hepatic AMLs
- Eyes: retinal hamartomas
- Bone: sclerotic lesions
- Oral: dental pits, gingival fibromas
Slide 31 - VHL Title
Slide 32 - VHL Pathophysiology
- Chr 3p25-26 (pVHL). AD.
- Loss → HIF-α accumulates → VEGF ↑ → highly vascular tumors (CNS, kidney, adrenal, retina, pancreas)
Slide 33 - CNS Hemangioblastomas
- Most characteristic VHL lesion
- Sites: cerebellum > spinal cord > brainstem
- MRI: cyst + enhancing mural nodule (classic)
- Retinal hemangioblastoma = earliest VHL manifestation (fundoscopy)
Slide 34 - Renal Cell Carcinoma (Clear Cell)
- Most common cause of death in VHL
- CT: bilateral, multiple, hypervascular
- MRI: T1 ↓, T2 ↑, early enhancement
Slide 35 - Pancreas + Pheo
- Pancreas: cysts, serous cystadenomas, pNETs
- Pheochromocytoma (10-20%): MRI "light bulb sign" = markedly T2 bright; intense enhancement
- Clinically: episodic HTN, headache, sweating
Slide 36 - Endolymphatic Sac Tumor
- CT: destructive posterior petrous bone lesion
- MRI: heterogeneous T1+T2, intense enhancement, intralesional hemorrhage
- Presents: hearing loss, vertigo, tinnitus
Slide 37 - SWS Title
Slide 38 - SWS Overview
- Sporadic. GNAQ somatic mutation (not inherited)
- Triad: port-wine stain (V1) + leptomeningeal angiomatosis + ocular vascular abnormality
- Mechanism: venous hypertension → ischemia → atrophy + calcification
Slide 39 - SWS Imaging
- CT: tram-track (gyriform) calcifications + ipsilateral atrophy + enlarged choroid plexus
- MRI: pial enhancement (parieto-occipital) + dilated deep medullary veins
- SWI/GRE: abnormal venous vasculature
Slide 40 - Other Syndromes Title
Slide 41-42 - Ataxia Telangiectasia
- ATM gene mutation. Autosomal recessive.
- Most common cerebellar ataxia in children <5 yrs
- MRI: progressive cerebellar atrophy (vermis first) + T2 WM hyperintensities + capillary telangiectasias (SWI: focal hypointense foci)
Slide 43 - Parry-Romberg
- Progressive hemifacial atrophy (skin, soft tissue, bone)
- Unilateral. Slowly progressive.
Slide 44 - Gorlin-Goltz (Basal Cell Nevus Syndrome)
- Key features: basal cell carcinomas + odontogenic keratocysts + falx calcification + bifid ribs
- Tumor risk: medulloblastoma + meningioma
Slide 45 - PHACES Syndrome
- Female predominance
- Posterior fossa malformation + Hemangioma (facial) + Arterial anomalies + Cardiac defects/coarctation + Eye abnormalities + Sternal defects
Slide 46 - Incontinentia Pigmenti
- X-linked. Skin + brain + eyes + teeth.
- MRI: brain infarction, cerebral atrophy, corpus callosum hypoplasia, T2 WM hyperintensities
Slide 47 - Cowden Syndrome
- PTEN mutation. Multiple hamartomas + cancer risk (breast, thyroid, endometrial, RCC)
- Lhermitte-Duclos Disease (LDD) = associated cerebellar lesion
- MRI: unilateral cerebellar hemisphere, "tiger-striped" T2 hyperintensity with folial thickening
Slide 48 - References / End
Key sources: RadioGraphics 2022, Indian J Radiol Imaging 2020, Osborn's Brain.
One-liner Memory Hooks:
- NF1 = 17, café spots, target sign, FASI, optic glioma
- NF2 = 22, bilateral schwannomas, ice-cream cone IAC
- TSC = mTOR, tubers + SEN + SEGA + AML + LAM + rhabdomyoma
- VHL = 3p, cyst-nodule hemangioblastoma, light bulb pheo, ccRCC
- SWS = GNAQ, tram-track Ca++, pial enhancement
- Gorlin = falx Ca++ + medulloblastoma
- LDD/Cowden = tiger-striped cerebellum
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