Letter of response re “Whole spine MRI is not required in investigating uncomplicated paediatric lumbosacral lipoma. A retrospective single-institution review” by Horsfall et al
We are grateful to Dr. Wang and colleagues for their interest in our article and for the comments they raise in respect of the association between lumbosacral lipoma (LSL) and syringomyelia. As illustrated by our data, the incidence of spinal cord cavities (hydromyelia or syringomyelia) in the context of LSL is much higher than in the general population, suggesting that there is an aetiological association between the two. However, the pathophysiology, natural history and prognostic implications of these cavities are far from clear. To date, our management algorithm for children with LSL has been primarily based on clinical evaluation (neurological and urological) rather than imaging findings. Our assertion is that the radiological finding of an associated syrinx, in an asymptomatic patient, does not alter the initial decision making process. Clearly, if a child has additional symptoms/signs such as scoliosis, which might suggest pathology elsewhere in the spinal cord, then we would agree more extensive imaging is indicated.
The patients in our series had not undergone surgery at the time of the MRI scan. In the discussion, we state that the recommendation for loco-regional imaging refers to “the initial investigation and work up of LSL”. We have not specifically looked at, or commented on post-surgical imaging or surveillance as this was not the remit of the paper. In a child who presents with recurrent, progressive or atypical symptoms after surgery, then more extensive spinal imaging may well be indicated. This comment is relevant to Fig 1c. provided by Professor Wang which is a case of re-tethering of LSL.
The extended LSL MRI protocol suggested by Prof Wang is interesting and might provide a pragmatic compromise between local and whole neuraxis imaging. Nonetheless, neurosurgeons need to be mindful that in extending the coverage of MR imaging occasional subclinical anomalies, of unknown significance will be found, potentially adding to the V.O.M.I.T. burden  rather than aiding in medical care.
There continue to be numerous controversies surrounding this complex dysraphic entity of LSL. As a result of the enthusiasm, clinical and academic output of groups such as Prof Wang’s, this is a subject that continues to evolve. It is important that perceived wisdom and dogma continue to be challenged in order to maintain the momentum of that evolution.
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Conflict of interest
The author has no conflict of interest.