"type A: optic nerves only"
"type B: chiasm involved (with or without optic nerve involvement)"
"type C: hypothalamic involvement and/or other adjacent structures"
"T1: enlargement, often iso to hypointense compared to the contralateral side"
"T1 C+ (Gd): enhancement is variable, characteristic absence of the tram-track sign"
"enlargement of the optic nerve and the mass may either be fusiform or exophytic in appearance."
"These tumours have sometimes been divided into optic pathway gliomas and hypothalamic gliomas (not to be confused with hypothalamic hamartomas). In cases where a tumour is confined to the optic nerves (Dodge stage 1 - see below), they can safely be referred to as optic nerve gliomas. Often, however, they are either centred on the chiasm or extend to involve the optic radiations. In such cases, they are difficult to distinguish from hypothalamic gliomas, and such a distinction is, in most instances, artificial. In such more posterior cases, the term hypothalamic-optochiasmatic glioma is perhaps more accurate, although not widely used."
"These tumours have sometimes been divided into optic pathway gliomas and hypothalamic gliomas (not to be confused with hypothalamic hamartomas). In cases where a tumour is confined to the optic nerves (Dodge stage 1 - see below), they can safely be referred to as optic nerve gliomas. Often, however, they are either centred on the chiasm or extend to involve the optic radiations. In such cases, they are difficult to distinguish from hypothalamic gliomas, and such a distinction is, in most instances, artificial. In such more posterior cases, the term hypothalamic-optochiasmatic glioma is perhaps more accurate, although not widely used."
"These tumours have sometimes been divided into optic pathway gliomas and hypothalamic gliomas (not to be confused with hypothalamic hamartomas). In cases where a tumour is confined to the optic nerves (Dodge stage 1 - see below), they can safely be referred to as optic nerve gliomas. Often, however, they are either centred on the chiasm or extend to involve the optic radiations. In such cases, they are difficult to distinguish from hypothalamic gliomas, and such a distinction is, in most instances, artificial. In such more posterior cases, the term hypothalamic-optochiasmatic glioma is perhaps more accurate, although not widely used."
"These tumours have sometimes been divided into optic pathway gliomas and hypothalamic gliomas (not to be confused with hypothalamic hamartomas). In cases where a tumour is confined to the optic nerves (Dodge stage 1 - see below), they can safely be referred to as optic nerve gliomas. Often, however, they are either centred on the chiasm or extend to involve the optic radiations. In such cases, they are difficult to distinguish from hypothalamic gliomas, and such a distinction is, in most instances, artificial. In such more posterior cases, the term hypothalamic-optochiasmatic glioma is perhaps more accurate, although not widely used."
"These tumours have sometimes been divided into optic pathway gliomas and hypothalamic gliomas (not to be confused with hypothalamic hamartomas). In cases where a tumour is confined to the optic nerves (Dodge stage 1 - see below), they can safely be referred to as optic nerve gliomas. Often, however, they are either centred on the chiasm or extend to involve the optic radiations. In such cases, they are difficult to distinguish from hypothalamic gliomas, and such a distinction is, in most instances, artificial. In such more posterior cases, the term hypothalamic-optochiasmatic glioma is perhaps more accurate, although not widely used."
"As such, generally, the term optic pathway glioma is favoured, recognising that there may be involvement of the hypothalamus."
"H + or - : hypothalamic involvement"
"Radiotherapy is associated with an increased risk of secondary central nervous system malignancies and neurocognitive complications. It is therefore only used in older children (>8-10 years) and cases where chemotherapy has failed to halt the progression of the disease 10. The typical radiation dose ranges from 45-54 Gy delivered in fractions of 1.8-2 Gy 14."
"The mode and frequency of surveillance for patients with neurofibromatosis type 1 but without diagnosed optic pathway gliomas vary depending on local preference and resources. The European Reference Network on Genetic Tumour Risk Syndromes (ERN GENTURIS) 2023 guidelines suggest the following 13:"
"The mode and frequency of surveillance for patients with neurofibromatosis type 1 but without diagnosed optic pathway gliomas vary depending on local preference and resources. The European Reference Network on Genetic Tumour Risk Syndromes (ERN GENTURIS) 2023 guidelines suggest the following 13:"
Expected headings
"Surveillance"
"Radiographs no longer have a role in the diagnosis of orbital masses; however, if performed, enlargement of the optic canal may be demonstrated if a tumour is not confined to the orbit. Additional findings of neurofibromatosis type 1 may also be visible in relevant patients."
"clinical assessment for optic pathway gliomas should start immediately after neurofibromatosis type 1 diagnosis or suspicion, with a baseline ophthalmology assessment at presentation by trained paediatric or neuro-ophthalmologists, including age-appropriate evaluation of visual acuity, visual fields, pupillary testing, eye movements, and optic disc appearance; 6 to 12-month reviews are recommended, particularly in children and if any visual symptoms develop"
"The main differential diagnosis is optic nerve meningioma; however, the list is much longer, including most causes of optic nerve enlargement. The absence of calcification can aid in differentiating optic nerve glioma from optic nerve sheath meningioma, which occurs more commonly in the latter 6."
"clinical assessment for optic pathway gliomas should start immediately after neurofibromatosis type 1 diagnosis or suspicion, with a baseline ophthalmology assessment at presentation by trained paediatric or neuro-ophthalmologists, including age-appropriate evaluation of visual acuity, visual fields, pupillary testing, eye movements, and optic disc appearance; 6 to 12-month reviews are recommended, particularly in children and if any visual symptoms develop"