Benign but not inconsequential, paediatric sciatic nerve neuromuscular choristoma and its longitudinal impact: A case report

Table 1 Timeline of imaging and clinical care

Timepoint and modality	Key findings and measurements	Clinical impression action	Patient age
2017 (MRI)	Nerve diameter: 2.7 cm	Baseline measurement	3 years, 5 months
2019 (MRI pelvis)	Nerve diameter: Increased to about 3.1 cm. Anatomy: Fusiform enlargement (L4-S2); isointense to muscle. Negatives: No bone lesions or soft tissue masses	NMC. Conservative management	5 years, 5 months
August 2024 (follow-up MRI)	AP diameter: 2.6 cm (post to ischium). Transverse: 3.2 cm (ischial tuberosity). Morphology: Unchanged; no malignant signal	Stable disease. Continued conservative approach for tumor	10 years, 5 months
December 2024 (standing X-Ray)	LLD: 2.5 cm (left side shorter; tibial origin). Spine: Pelvic tilt with compensatory right scoliosis. Foot: Left calcaneal deformity (elevated heel)	Confirmed indication for guided growth surgery to address LLD	10 years, 7 months
August 2025 (surgery)		Right proximal tibial epiphysiodesis (8-plate) performed to slow growth on contralateral limb	11 years, 5 months
November 2025 (interval MRI)	AP diameter: 3.0 cm. Transverse: 3.3 cm. Anatomy: Gross hypointense thickening (L4-S2) and L5 root thickening	Fairly stable. Slight measurement increased attributed to difficult morphology rather than progression	11 years, 7 months

MRI: Magnetic resonance imaging; LLD: Leg length discrepancy; NMC: Neuromuscular choristoma; AP: Anteroposterior.

Table 2 Comparison of our case to other reports in the literature with regard to orthopaedic sequelae described and follow-up emphasis

Ref.	Main focus	Orthopaedic sequelae described	Follow-up emphasis	Why our case adds value
Kumar et al[14], 2014	Nerve-territory undergrowth in sciatic/lumbosacral NMC	Yes: Limb shortening and hip dysplasia	Mechanistic association and phenotype description	Our case extends this by detailing longitudinal surveillance, orthopaedic decision-making and timing of guided growth intervention
Park[9], 2019	Long-term natural history of sciatic NMC	Orthopaedic issues not the primary focus	Neurological and radiological stability over long follow-up	Our case complements this by showing that prolonged lesion stability may coexist with progressive orthopaedic burden requiring treatment
Present case	Longitudinal paediatric multidisciplinary management	Yes: Limb length discrepancy, pelvic obliquity, scoliosis, achilles contracture, calcaneal deformity	Orthopaedic surveillance and post-biopsy conservative nerve management	Distinguishing contribution is the detailed orthopaedic pathway from observation to guided growth planning and intervention near skeletal maturity

NMC: Neuromuscular choristoma.