Confirm NF1 using current clinical and genetic criteria
The 2021 international consensus criteria updated the classic NF1 diagnostic framework and incorporated molecular testing. Typical features can include café-au-lait macules, axillary or inguinal freckling, neurofibromas or plexiform neurofibroma, optic pathway glioma, characteristic ocular findings, selected osseous lesions, an affected parent and a pathogenic NF1 variant. A genetics-first review is particularly useful in young children, mosaic or atypical presentations and families where pigmentary findings overlap with Legius syndrome or another RASopathy.
Genetic counseling matters because NF1 is a lifelong familial condition
Molecular confirmation can support diagnosis, clarify atypical presentations and help family counseling, but a laboratory result should be interpreted together with the phenotype. A specialist consultation may address inheritance, testing of relatives, reproductive questions and mosaic NF1. Variants of uncertain significance should not be treated as a confirmed molecular diagnosis without appropriate interpretation.
Do not turn surveillance into indiscriminate repeated scanning
NF1 surveillance should be age- and manifestation-specific. ERN GENTURIS guidance uses clinical review plus targeted investigations for defined tumor risks rather than automatic repeated full-body imaging for every patient. Imaging should answer a clinical question such as growth of a known plexiform neurofibroma, new neurological symptoms, suspected malignant transformation, optic-pathway concern or another organ-specific risk.
Plexiform neurofibromas need symptom, anatomy and growth assessment
Plexiform neurofibromas can be superficial or deep and may affect pain, motor function, airway, bowel or bladder function, vision, appearance or nearby organs. MRI is commonly used to define extent; volumetric assessment can be useful when following a complex tumor or evaluating treatment response. The key questions are whether the tumor is symptomatic, progressive, surgically resectable and suspicious for malignant change.
Surgery remains important when a symptomatic tumor can be removed safely
Resection can be appropriate for selected symptomatic, disfiguring or function-threatening neurofibromas and plexiform neurofibromas. Complete removal is not always possible because plexiform tumors may extend through multiple nerve branches and critical structures. A specialist surgical plan should therefore compare likely functional benefit with neurological deficit, bleeding, wound, recurrence and reconstruction risks rather than promise complete removal.
MEK inhibitors are now a real treatment pathway for selected inoperable plexiform neurofibromas
EU-authorized systemic options for symptomatic, inoperable NF1-associated plexiform neurofibromas include selumetinib and mirdametinib. The current EMA product information should be checked for exact age, formulation and prescribing criteria. These medicines are not general treatment for every person with NF1 or every cutaneous neurofibroma; they require specialist selection, baseline review and ongoing monitoring for treatment response and adverse effects.
Rapid growth or new persistent pain changes the pathway to MPNST assessment
NF1 increases the risk of malignant peripheral nerve sheath tumor (MPNST). A previously stable tumor that becomes rapidly larger, persistently painful, hard or neurologically symptomatic should not simply be watched until the next routine visit. Specialist assessment can include focused MRI and, when appropriate, metabolic imaging and tissue diagnosis planned by an experienced tumor or sarcoma team so that biopsy does not compromise definitive surgery.
Optic-pathway and other NF1-associated tumors require organ-specific expertise
NF1 can involve optic pathway glioma and other central or peripheral nervous-system tumors, as well as tumors and complications outside neurology. Surveillance and treatment therefore may require ophthalmology, neuroradiology, neurosurgery, oncology, dermatology, orthopedics, genetics, endocrinology or sarcoma expertise depending on the phenotype. An NF center is valuable because it coordinates these pathways rather than treating each lesion in isolation.
Learning, attention and neuropsychological needs are part of NF1 care
Cognitive, attention, school or psychosocial difficulties can be clinically important even when tumor burden is limited. UKE's NF program includes neuropsychological diagnostics and counseling. For children and adults with functional concerns, a second opinion should include the question of whether formal neuropsychological assessment, educational support or rehabilitation is appropriate.
UKE Hamburg has a dedicated interdisciplinary NF1 and schwannomatosis program
University Medical Center Hamburg-Eppendorf operates a dedicated Neurofibromatosis Clinic and Day Clinic for children, adolescents and adults with NF1 and schwannomatosis. The program publishes molecular-genetic diagnostics, genetic counseling, neuropsychological assessment, tumor volumetry, infusion treatment and an interdisciplinary NF board. UKE states that the clinic follows around 1,700 patients per year, making it a strong verified German referral option for complex NF1 second opinions and treatment planning.
What to send for a German NF1 second opinion
A useful review needs the phenotype and tumor history, not only a genetic report.
- NF1 genetic test report, including variant classification and method
- Clinical genetics or neurology summary documenting diagnostic criteria
- Family history and prior testing of relatives
- MRI DICOM files for known plexiform neurofibromas or other tumors
- Prior whole-body MRI if available
- Serial imaging demonstrating tumor growth
- Operative and pathology reports for previous neurofibromas or nerve-sheath tumors
- Current symptoms: pain, weakness, sensory change, vision, swallowing, breathing, bowel/bladder or mobility problems
- Ophthalmology reports when optic-pathway disease is relevant
- Previous oncology, sarcoma, dermatology, orthopedic or neuropsychology assessments
- Current medicines and any prior MEK-inhibitor treatment with response and toxicity
- Exact question: confirm diagnosis, assess a plexiform neurofibroma, review surgery, evaluate MEK therapy, investigate possible MPNST or design surveillance
Do not delay urgent assessment for a rapidly changing tumor
Rapid tumor enlargement, new persistent or nocturnal pain, new weakness or sensory loss, acute visual change, major airway symptoms or another rapidly progressive neurological deficit require prompt local or specialist assessment. Planned international travel should not delay evaluation of suspected malignant transformation or acute neurological compromise.
Official sources
Sources last checked 2026-09-03. Clinical pathways, eligibility and hospital procedures can change; confirm current requirements directly with the treating center.
- UKE Neurofibromatosis Clinic and Day Clinic — University Medical Center Hamburg-Eppendorf (UKE) ↗
- ERN GENTURIS NF1 tumour surveillance guideline — European Reference Network GENTURIS ↗
- Revised diagnostic criteria for NF1 and Legius syndrome — Genetics in Medicine / International Consensus Group ↗
- Koselugo (selumetinib) EPAR — European Medicines Agency ↗
- Ezmekly (mirdametinib) EPAR — European Medicines Agency ↗