A 50-year-old male presented to the emergency room after experiencing sudden right upper limb facial numbness and dysphasia, followed by full recovery. A brain CT scan showed hyperdense lesions within the left hemispheric sulcus, which raised suspicion of spontaneous subarachnoid hemorrhage. A T1-weighted MRI showed multiple tiny leptomeningeal enhancements in the same area, and a digital subtraction angiography showed no signs of vascular abnormality. Cerebrospinal fluid cytology revealed atypical melanin-containing cells with minimal pleomorphism. One month later, the patient developed sixth nerve palsy, which was determined to be due to intracranial hypertension. Multiple giant nevi on the legs, trunk, and scalp were also observed. A skin biopsy showed well-defined and symmetrical proliferation of melanocytic nevus cell nests in the dermis. An open biopsy was performed due to the suspicious leptomeningeal lesions, which surprisingly revealed diffuse and thick black-colored tissue infiltration of the leptomeninges. Pathology confirmed the diagnosis of meningeal melanocytosis. A ventriculoperitoneal shunt was then placed, and the patient\'s neurological symptoms gradually improved. Based on the presence of multiple giant nevi on the patient\'s skin and the finding of diffuse meningeal melanocytosis during the open biopsy, the patient was diagnosed with neurocutaneous melanosis. The patient received 6 cycles triweekly of Ipilimumab and Nivolumab 8 months after initial diagnosis. Unfortunately, the disease progressed and the patient passed away 14 months after initial diagnosis.

UNASSIGNED: Primary melanocytic tumors of the central nervous system accounts for approximately 1% of all melanoma with a peak incidence in the fourth decade. The tumor originates from leptomeningeal melanocytes with a variable degree of belligerence. The proliferation of these melanocytes in large amounts in the dermis and nervous system can raise suspicion of neurocutaneous melanosis (NCM), which is an association between malignant melanoma and the presence of a giant intradermal nevus.
UNASSIGNED: We present a case of a 62-year-old South Asian male with a large congenital melanocytic nevus (>20 cm in size) in the left hemifacial, and head region who presented with complaints of a single episode of grand-mal seizure followed by neuropsychiatric symptoms. The patient was thoroughly evaluated both clinically and surgically leading to a rare diagnosis of primary leptomeningeal melanoma of the left temporal lobe. The patient subsequently underwent a neuronavigation guided left temporal craniotomy with gross total resection of the lesion.
UNASSIGNED: Primary leptomeningeal melanoma with a clinical association with NCM is rarely ever reported within the literature. To date, our case is one of the very few instances where such an association is being reported in this age group along with rare neuropsychiatric symptoms.

BACKGROUND: Primary meningeal melanocytic neoplasms are exceedingly rare tumors, representing only 0.06% to 0.1% of all primary brain tumors and ranging in spectrum from benign localized tumors to highly aggressive malignant lesions. The diagnosis of these tumors is often challenging from clinical, radiological, and pathologic standpoints. Equally challenging is the distinction between primary meningeal melanocytic neoplasm and metastatic melanoma.
METHODS: The authors reported the case of a 41-year-old man with imaging findings diagnostic of neurofibromatosis type 2: bilateral internal auditory canal lesions (most consistent with bilateral vestibular schwannomas), two dura-based lesions presumed to be meningiomas, multiple spinal lesions consistent with peripheral nerve sheath tumors, and one intramedullary spinal lesion consistent with an ependymoma. Biopsy of these lesions revealed melanocytic neoplasms with mild to moderate atypia and a mildly elevated proliferation index, which made the distinction between benign and malignant challenging. In addition, the disseminated nature of these tumors made it difficult to determinate whether they arose from the meninges or represented metastases from an occult primary melanoma.
CONCLUSIONS: This case illustrated the challenges presented by the diagnosis of meningeal melanocytic neoplasms and highlighted the importance of integrating the clinical and radiographic findings with histologic appearance and molecular studies.

BACKGROUND: Neurocutaneous melanosis (NCM) is a rare congenital, nonhereditary neurocutaneous syndrome that mainly occurs in children; adult NCM is very rare. Due to its rarity, the clinical features and treatment strategies for NCM remain unclear. The purpose of this study was to explore the clinical features, diagnosis, treatment and prognosis of NCM in adults. Most intracranial meningeal melanomas are solid masses, and cystic-solid malignant melanomas are very rare. Due to the lack of data, the cause of cystic changes and the effect on prognosis are unknown.
METHODS: A 41-year-old woman was admitted to the hospital with intermittent headache for 1 mo. Magnetic resonance imaging (MRI) showed a 4.7 cm × 3.6 cm cystic-solid mass in the left temporal lobe with peritumoral edema. The entire mass was removed, and postoperative pathology indicated malignant melanoma.
CONCLUSIONS: MRI is the first-choice imaging approach for diagnosing central nervous system diseases in NCM patients, although cerebrospinal fluid may also be used. At present, there is no optimal treatment plan; gross total resection combined with BRAF inhibitors and MEK inhibitors might be the most beneficial treatment.

Neurocutaneous melanosis is caused by postzygotic NRAS mutations in neural crest cells, resulting in large or multiple nevi in the skin and proliferation of leptomeningeal melanocytes in the central nervous system. The onset of neurological symptoms is usually before the age of 2 years, but it can also occur in adults. A 35-year-old male had been asymptomatic for a long time after excision of a large congenital melanocytic nevus, but he developed headache, disturbance of consciousness, and seizure. Methotrexate was ineffective, cerebral pressure was decreased by spinal drainage, and steroid pulse therapy was temporarily effective. Seizures and disturbance of consciousness worsened and the patient died on the 92nd day. Cerebrospinal fluid human melanin black-45 immunostaining and serum 5-S-cysteinyldopa (5-S-CD) were useful in diagnosing melanocytic proliferation, and serum 5-S-CD may be useful in predicting prognosis.

Giant melanocytic nevus is a rare condition caused by benign proliferation of melanocytes. There is a slight risk of malignancy in these lesions which should be noticed especially when they become larger. GCMN can be removed by plastic surgery.

BACKGROUND: A giant congenital melanocytic nevus (GCMN) is found in 0.1% of live-born infants. If present, the lesion has a chance of about 6% to develop into malignant melanoma. Both children and adults can be affected by malignant melanoma arising in a giant congenital nevus. Up to 95% of GCMNs harbor NRAS mutations, and mutations in the BRAF, MC1R, TP53, and GNAQ genes have also been described. The individualization of therapy is required, but diagnostic and prognostic criteria remain controversial.
METHODS: We report two cases: 1) melanoma arising in a giant congenital nevus during the first month of life complicated with neurocutaneous melanosis (NCM), and 2) melanoma arising in a giant congenital nevus during the first 6 months of life. Pathology, immunohistochemistry, and genetic analyses of tumor tissue were performed. The first case revealed only a non-pathogenic P72R polymorphism of the TP53 gene in the homozygote condition. For the second case, a Q61K mutation was detected in the NRAS gene.
CONCLUSIONS: Malignant melanoma associated with GCMN is rare and therefore poorly understood. Outcomes have been linked to the stage at diagnosis, but no additional pathological prognostic factors have been identified. The most frequent genetic event in giant CMNs is NRAS mutations, which was discovered in one of our cases. To accumulate evidence to improve disease prognosis and outcomes, children with congenital melanocytic nevus should be included in a systemic follow-up study from birth.

BACKGROUND: Neurocutaneous melanosis is a rare phakomatosis characterized by large or multiple pigmented nevi and melanosis of the leptomeninges. It is often complicated by hydrocephalus due to melanotic deposits interfering with cerebrospinal fluid reabsorption in the basal cisterns or causing foraminal or aqueductal obstruction. In 10% of cases, it will be associated with the Dandy-Walker complex.
METHODS: We present the case of a 6-year-old girl with multiple congenital hairy nevi presenting with generalized tonic-clonic seizures, headache, and vomiting. Neuroimaging showed a communicating hydrocephalus associated with the Dandy-Walker variant, melanotic deposits in the amygdalae, thalami, and cortical sulci, and abnormal leptomeningeal enhancement. After undergoing ventriculoperitoneal shunt insertion, the symptoms of increased intracranial pressure abated. However, she again showed deterioration 1 month postoperatively due to progressive leptomeningeal spread suspicious for malignant degeneration.
CONCLUSIONS: The results of the present case and the findings from a review of related data suggest that shunt insertion (ventriculoperitoneal or cystoperitoneal) is an effective palliative measure for patients with neurocutaneous melanosis with associated hydrocephalus. Despite treatment, however, the prognosis of these patients remains poor owing to malignant progression and leptomeningeal spread of lesions, in particular, in cases associated with the Dandy-Walker complex.

Neurocutaneous melanosis (NCM) is a sporadic condition characterised by congenital melanocytic nevi and melanocytic thickening of the leptomeninges. It is believed to result from congenital dysplasia of melanin-producing cells within the skin and leptomeninges. The management of cutaneous manifestations remains controversial; for neurological manifestations, outcome remains poor even with the use of radiotherapy and chemotherapy.
We describe the case of a 5-month-old boy who presented with giant congenital melanocytic nevus and hydrocephalus. MR imaging and CSF immunohistochemistry confirmed leptomeningeal melanosis. We discuss the diagnosis, treatment and prognosis of this rare disorder in the light of recent published literature.
Patient required placement of right-sided ventriculoperitoneal shunt to control hydrocephalus. The patient tolerated the procedure well and was discharged home with normal neurological function. A presumptive diagnosis of NCM was made based on the MR characteristics, CSF cytology and clinical presentation. He received trametinib, a MAPK/Erk kinase inhibitor for 7 months. At 30 months of age, he developed left-sided weakness and status epilepticus requiring paediatric intensive care unit admission and ventilator support. The patient eventually succumbed to malignant transformation of leptomeningeal disease.
Cutaneous manifestations of NCM are usually congenital, and neurological manifestations develop early in life. Patients with large or multiple congenital nevi should therefore be investigated early to facilitate treatment. MR imaging is the investigation of choice which can further assist in performing biopsy. Symptomatic NCM is refractory to radiotherapy and chemotherapy and has a poor prognosis. A multidisciplinary approach is necessary in the management of NCM patients.

BACKGROUND: To explore the clinical characteristics of neurocutaneous melanosis (NCM) in adult patients to help improve diagnosis and treatment of this disease, we present a rare case of an adult patient suffering from NCM with malignant melanoma, as well as a review of the relevant Chinese and English literature.
METHODS: The patient reported here plus the patients identified in our literature review total 30 adults with NCM (20 males [66.7%] and 10 females [33.3%]), age 19-65 years (average, 27.9 years). These include 24 cases of malignant melanoma (80.0%), 3 cases of melanocytoma (10.0%), 2 cases of diffuse melanocytosis (6.7%), and 1 case of unknown pathology (3.3%). Satellite nevi were reported in 25 cases (83.3%) and in 5 cases their presence was unknown (16.7%). Intracranial lesions were present in 28 cases (93.3%), and intraspinal lesions were present in 2 cases (6.7%). There are 4 cases of combined hydrocephalus (13.3%), and 2 cases of combined Dandy-Walker deformity (6.7%).
CONCLUSIONS: NCM is a rare disease, especially in adults. With the onset of symptoms, the diagnosis is generally confirmed. In children with congenital giant nevus, regular periodic surveys of the central nervous system (brain and spinal cord) with magnetic resonance imaging or cerebrospinal fluid analysis should be performed to diagnose NCM. Active treatment should be undertaken to improve the prognosis.