Table 2.

Clinical and radiological features of the 18 patients with abnormal magnetic resonance imaging (MRI) scans (classified as group 2, ‘other pathology’)

Patient	Sex	CMN projected adult size (cm)	Total naevi at enrolment (n)	MRI findings at first scan, with subsequent progress	Neurological symptoms by time of first MRI	Seizures ever	Neurodevelopmental problems (ever)	Neurodevelopmental details	Neurosurgery	Death from cutaneous melanoma	Death from CNS melanoma
1	M	> 60	20–50	Generalized lack of white matter bulk, slightly prominent ventricles, low‐volume inferior vermis Appearances stable on repeat MRI (×1), neurologically normal at age 8 years	No	No	No	–	No
2	M	> 60	100–200	Multiple foci of intraparenchymal melanosis amygdala, temporal lobe and cerebellum Right cerebellar hemisphere small Appearances stable on repeat MRI (×1) ADHD diagnosed at age 4 years	No	No	Yes	ADHD, mild developmental delay, speech therapy, extra help in class, mainstream school	No
3	M	20–40	20–50	Leptomeningeal enhancement over anterior surface of conus and along the nerve roots of the cauda equina Appearances stable on repeat MRI (×2), neurologically normal at age 4 years	No	No	No		Yes
4	F	10–20	< 10	Filum terminale lipoma Lateral ventricles large right > left but not hydrocephalus; some lack of white matter bulk and cortical thinning Appearances stable on repeat MRI (× 1), neurologically normal at age 10 years	No	No	No		No
5	F	40–60	> 200	Multiple foci of intraparenchymal melanosis amygdala, cerebellum; two benign intradural tumours (one melanocytic, one neurocristic hamartoma), DWM hydrocephalus, later syrinx within spine Multiple MRI scans, DWM resolved, diffuse leptomeningeal disease (melanocytic on histology but no characteristic melanin signal on MRI) spread over first year to involve all leptomeninges, cord compression gradually worsening In wheelchair with moderate global developmental delay at age 10 years	No	Yes	Yes	Moderate global developmental delay, wheelchair bound	Yes
6	M	10–20	2	Right lateral ventricle choroid plexus papilloma, hydrocephalus	No	Yes	No		Yes
7	F	Multiple	10–20	Multiple foci of intraparenchymal melanosis plus multiple focal nonmelanin signal spinal thoracic dural deposits Not biopsied, stable on repeat MRI (×2), neurologically normal at age 5 years	No	No	No		No
8	F	> 60	50–100	Extramedullary dural stranding	No	No	No		No
9	M	< 10	Multiple but exact number unknown	Right cerebellar astrocytoma	No	No	No		Yes
10	M	20–40	> 200	Intraparenchymal melanosis of both thalami and mesial temporal lobes (left > right), venous angioma left cerebellar hemisphere	No	Yes	Yes	Moderate cognitive delay, special school	Yes
11	M	40–60	100–200	Intraparenchymal melanosis of left amygdala Equivocal enhancement of nerve roots of cauda equina	No	No	No		No
12	Male	40–60	Multiple but exact number unknown	Midline posterior fossa arachnoid cyst, communicating hydrocephalus	No	Unknown	Unknown		Yes
13	M	10–20	< 10	Left frontal lobe meningioma	No	No	No		Yes
14	M	10–20	< 10	Subtle enhancement of nerve roots of cauda equina	No	No	No		No
15	M	> 60	20–50	Multiple foci of intraparenchymal melanosis and diffuse leptomeningeal melanoma	No	No	Yes		Yes	Yes
16	M	–	Multiple but exact number unknown	Posterior fossa malignant melanoma	Yes	Unknown	Yes		Yes		Yes
17	F	No single larger lesion Largest lesion projected adult size < 5 cm	> 200	Diffuse leptomeningeal melanosis and DWM with hydrocephalus at 2 weeks At 6 months diffuse leptomeningeal melanoma with focus of intraparenchymal melanoma	No	Yes	Yes	Moderate global delay	Yes		Yes
18	F	> 60	20–50	Intraparenchymal melanosis and subsequent diffuse leptomeningeal melanoma with hydrocephalus	Yes	No	Yes	Mild developmental delay prehydrocephalus	Yes		Yes

CMN, congential melanocytic naevi; CNS, central nervous system; M, male; ADHD, attention deficit hyperactivity disorder; F, female; DWM, Dandy–Walker malformation.