2. Group of CNS disorders characterized by
• brain malformations or
• neoplasms
• skin
• eye lesions.
The term is derived from the Greek root phako, which
refers to the lens
phakomatosis means -tumor-like condition of the eye
(lens)
Neurocutaneous Syndromes
/ Phakomatoses
24. Cortical Tubers
• Cortical tubers are firm, whitish, pyramid-shaped,
elevated areas of smooth gyral thickening, with or
without central depressions, that grossly resemble
potatoes ("tubers")
• On CT scan,
Seen as hypodense cortical/subcortical masses within
broadened and expanded gyri
Calcifications in cortical tubers increase with age
• Tubers in older children and adults demonstrate
mixed signal intensity on T2/FLAIR
28. Subependymal Nodules
• appear as elevated, rounded, hamartomatous lesions
• located beneath the ependymal lining of the lateral ventricles,
along the course of the caudate nucleus
• Are small(generally < 1.3cm) nodular "bumps" that protrude from
the walls of the lateral ventricles.
• In the unmyelinated brain, SENs appear hyperintense on T1WI and
hypointense on T2WI. With progressive myelination, the SENs
gradually become isointense with WM
• They often calcify with increasing age
• An enhancing or enlarging SEN—especially if located near the
foramen of Monro—is suspicious for SEGA.
• Calcified SENs appear variably hypointense on T2WI and are
especially easy to detect on T2* sequences
34. Subependymal Giant Cell Astrocytoma
• seen almost exclusively in the setting of TSC.
• well-circumscribed
• solid intraventricular masses
• located near the foramen of Monro.
• SEGAs are WHO grade I tumors that often
cause obstructive hydrocephalus.
most SEGAs are unilateral,
bilateral tumors occur in 10-15% of cases
35.
36.
37.
38. Genetic Criteria
• The identification of either a TSC1or
TSC2pathogenicmutation
in DNA from normal tissue is sufficient to
make a Definite Diagnosisof TSC
Mutations that lead to increased mTOR activation promote cellular disorganization, overgrowth, and abnormal differentiation that may result in tumorigenesis.
Targets for mTOR regulation of translational initiation and elongation. AMPK = AMP-activated kinase. TSC1 and TSC2 = Tuberous sclerosis tumor suppressors 1 (hamartin) and 2 (tuberin); Rheb = Ras homolog enriched in brain; PKB/Akt = protein kinase B; 4EBP1 = eIF-4E binding protein; p70S6K = 70kDa ribosomal protein S6 kinase, also called S6K; eEF2K = eukaryotic elongation factor 2 kinase.
Typical ash leaf macules(hypomelanotic macules); These may be present at birth, increase during early childhood and usually persist throughout life
the reddish, nodular area at the upper lumbar area is a shagreen patch(subepidermal fibrosis)
The most common skin lesions are hypomelanotic macules, which are ovoid depigmented areas with irregular margins that are best visualized by ultraviolet light (Woods lamp). These "ash leaf" spots are seen in over 90% of cases and may be the first visible manifestation of TSC
Multiple facial angiofibromas
These small bumps are usually scattered on the central face, especially on the nose and cheeks, and sometimes on the forehead,
Periungual fibromas
(Koenen's tumor)
Gingival fibromas and dental pitting
Axial cut section from the same case shows bilateral subependymal giant cell astrocytomas
Axial graphic of typical brain involvement in tuberous sclerosis complex shows a giant cell astrocytoma in the left foramen of Monro, subependymal nodules , radial migration lines , and cortical/subcortical tubers .
NECT scan shows additional calcified SENs , wedge-shaped hypodensities characteristic of the WM lesions in TSC
CECT scan shows enhancement adjacent to the foramen of Monro, suspicious for subependymal giant cell astrocytoma.
More cephalad scan shows additional hyperintense subependymal nodules as well as multiple hyperintense radial bands extending outward from the lateral ventricles.
More cephalad T2WI shows that the thickened radial bands are hypointense relative to the unmyelinated white matter.
tubers appear as thickened hyperintense cortex compared to the underlying unmyelinated WM on T1WI and become moderately hypointense on T2WI. "Streaky" linear or wedge-shaped T2/FLAIR hyperintense bands may extend from the tuber all the way through the WM to the ventricular ependyma
T2WI shows that the WM is largely unmyelinated. The SENs are isointense with gray matter. Cortical tubers have poor GM-WM delineation.
high signal intensity on non-fat saturated sequences, and loss of signal following fat saturation
Renal angiomyolipomas (AMLs) are a type of benign renal neoplasm and are composed of vascular, smooth muscle and fat elements.
Cardiac rhabdomyoma is type of benign myocardial tumour
May be seen as one or more solid hyper echoic mass(es) located in relation to the myocardium
Cardiac rhabdomyoma is type of benign myocardial tumour and is a most common fetal cardiac tumou
Chest CT scan: Multifocal pulmonary cysts characteristic of lymphangio-myomatosis (LAM)
