The Value of Imagistics in Early Diagnosis of Tuberous Scler
Now open: Certificate Course in Management of Covid-19 by Govt. Of Gujarat and PlexusMDKnow more...Now open: Certificate Course in Management of Covid-19 by Govt. Of Gujarat and PlexusMDKnow more...
Tuberous sclerosis complex (TSC) is a disorder of cellular differentiation, proliferation, and migration in early development characterized by the formation of benign, hamartomatous lesions in virtually any organ system. It is an autosomal dominant genetic disease, even if two-thirds of patients are found with sporadic mutations. The two involved protein-coding genes are TSC1 and TSC2, with an important role in suppressing the mammalian target of rapamycin pathway, influencing cell growth, and proliferation. The mutations cannot be identified by conventional genetic tests in a significant proportion of cases (10–25%), so negative results of genetic tests do not exclude TSC. Clinical criteria continue to be the main diagnosis way, the imagistic assessment being useful in early diagnosis.

A 4-month-old boy, without relevant personal history, from a gravida 6 para 5 pregnancy, accurately monitored, with a physiological course. Bilateral hydrocephalus, severe on the left side, was found by fetal ultrasound (32 w + 5 d). The probability of syndromic context was considered low, without any other anomalies. The fetal MRI showed severe ventriculomegaly; periventricular lesions along the ganglionic eminence area like a subependymal nodular heterotopia, with partial calcification; a bigger lesion was located next to the left foramen of

Monro typical for subependymal giant cell astrocytoma (SEGA), which can be responsible for cerebrospinal fluid disorder; an extra modification of MRI signal from the right lateral ventricle surface to the insular cortex, as a sign of transmantle cortical dysplasia. The fetal ultrasound (34 w + 4 d) showed an echogenic intracardiac tumor on the left ventricular apex, being interpreted as rhabdomyoma, due to the fetal MRI result.

It was a natural birth, at term, with physiological neonatal adaptation. The clinical exam at birth showed on the upper back midline a large (about 25 mm) erythematous plaque with the orange-peel surface, suggestive for Shagreen patch, and dermatologically confirmed (Wood's lamp). At birth, cranial ultrasound illustrated the bilateral increase of lateral ventricle, mostly on the left occipital horn. In the subependymal area were found the well-delimited, irregular, echogenic structures, some of them bumping inside lateral ventricles. The largest one was located near the left foramen of Monro (8/9 mm), with a slight mass effect.

Echocardiography revealed a hyperechogenic well-marked structure, without significant ventricular prolapse, typical for rhabdomyoma, inside of each ventricular apex. Indirect ophthalmoscopy identified on the left eye retina two smooth, noncalcified, translucent lesions, next to the upper temporal vascular arcade. Neurological and electroencephalographic examinations and abdominal ultrasound were normal.

The postnatal ultrasound follow-up demonstrated a slight increase of hydrocephalus, mostly of the occipital horn, with moderate asymmetry. At 8 weeks old, the first calcified, hyperechogenic area appeared next to the left foramen of Monro. Cardiac rhabdomyomas decreased in the right ventricular apex and could not be marked anymore in the left ventricular area. Indirect ophthalmoscopy monitoring registered multiple retinal hamartomas, two in the right eye and three in the left one (increasing in number).
Dermatological examination, including Wood's lamp, pointed outsize an increase of the Shagreen patch and appearing of hypomelanotic macules (ash leaf and confetti-like type). Neurological symptoms occur at 7 weeks old with seizures-like subtle crises. Vigabatrin was used as an anticonvulsant treatment, with a positive outcome.

Seven major criteria (hypomelanotic macules, Shagreen patch, multiple retinal hamartomas, cortical dysplasia, subependymal nodules, subependymal giant cell astrocytoma, and cardiac rhabdomyomas) and a minor one (“confetti” skin lesions) were taken into consideration.
The genetic diagnosis was done at 4 months old by sequencing analysis of the TSC1 and TSC2. A heterozygous likely pathogenic variant was identified in the TSC 2 gene—this finding is consistent with the genetic diagnosis of autosomal dominant tuberous sclerosis type.