Glomus tumours

Glomus tumours, or skull base paragangliomas, are rare neuroendocrine neoplasms arising in the lateral skull base. Normally benign, but locally invasive, they exhibit low rates of malignant transformation. They can be sporadic or associated with a predisposing genetic mutation in around 50% of patients, in which case synchronous and metachronous tumours can be found. They are often indolent and usually non-secreting. Many patients can therefore be managed conservatively with surveillance. When treatment is required, surgery can be curative, but is associated with high rates of cranial neuropathies. Radiotherapy has therefore been pursued as an alternative, and technical advances have made this an effective and safe treatment for tumour control. Radiation treatment is now the preferred approach in many cases. Surgery is still indicated in cases with brainstem compression, failed radiotherapy, and secreting tumours. There is also ongoing debate regarding subsets of patients with small growing tumours, which can be favourable for surgery and young patients where long-term control with radiotherapy is not yet established and late effects of radiotherapy need to be considered. There are many nuances in the decision making and optimal management requires an experienced multidisciplinary team including neurosurgeons, otologists, endocrinologists, geneticists, oncologists, radiologists, and pathologists.