4 yr old - possible tuberous sclerosis

[TSC Mum]

My 4 year old daughter has a possible diagnosis of tuberous sclerosis.  She has 3 areas of ash-leaf shaped hypopigmentation (one large area on chest and two on back of left calf).  She has 3 small round hypopigmented macules on her forehead.  She is developmentally delayed with the most profound area of delay being speech.  We do not experience seizures.  She has very low muscle tone but is otherwise healthy   She has had very occasional strabismus and there is a paternal family history of same. While consulting with a neurologist with respect to hypotonia and developmental delays, we pointed out the hypopigmentation on her chest and he sent us to a dermatologist who ordered further tests after finding more areas under a Wood's lamp.  We have had normal EEG, CT scan, kidney, heart, eye exams.  Our geneticist has classed us as a "possible" TSC because according to the newer TSC diagnostic criteria we only have one major criteria.  She says she has a strong suspicion that TSC is more than a possibility.  There is ongoing consultation about whether to undergo an MRI at this point. Our pediatrician is scoffing at even the possibility of TSC despite receiving the diagnostic criteria with the geneticist's report.  She maintains there are lots of disorders with hypopigmentation. The only disorder I have found that refers specifically to ash leaf shaped hypopigmentation is TSC.  Are there other disorders/syndromes, etc. where you see this shape of hypopigmentation, or is it possible the shape is coincidental?

[Alan Rockoff, MD]

It is hard to diagnose conditions like Tuberous Sclerosis with certainty in young children, in whom definitive criteria may not have developed yet.  I would follow the geneticisist's judgment over the general pediatrician's, however, since the generalist's experience with this uncommon condition is likely to be limited.  There are indeed other things which cause hypopigmenation, like eczema and vitiligo, but your child's situation certainly sounds like neither.

Granted that being sure of the diagnosis would provide a measure of comfort, the question I think you ought to ask before further workup is, "Will the results change the management?"  If the answer is not an unequivocal positive, you may want to consider deferring definitive diagnostic categorization to a later time.

Best.

Dr. Rockoff