To present a case series of de-novo central nervous system (CNS) tumours in adults with intellectual disabilities (ID).

Three cases of de-novo brain tumours in adults with (ID) were identified. The casenotes were reviewed and compared with the current evidence base of CNS tumours.

Three women aged 44-50 were identified with CNS tumours. Two cases with mild ID and one with severe ID. The first presented with depression. Cranial imaging was unremarkable. She experienced a seizure due to a benign meningioma. The woman had Bipolar Affective Disorder and diabetes mellitus presented with Parkinson’s Disease. Intracranial scanning revealed a diencepahlic tumour. The third woman had dysphagia and vertigo. Imaging identified two meningiomas.

The prevalence of primary CNS tumours in people with ID is uncertain. The presentation and histopathology of the three tumours varies. In all three, diagnosis was delayed perhaps due to diagnostic overshadowing. Establishing the characteristics of primary CNS tumours in adults with ID and their presentation should progress our knowledge. Further epidemiological research is required to establish the prevalence of tumours in adults with ID. The clinical management of CNS tumours in adults with ID must include exploration of the best interests of the person and the implications for end-of-life care. The authors acknowledge the limitations of a case series and recommend a national cohort as an epidemiological sample.