Report of Concomitant Intracranial Cysts in Unrelated Patients With Heterozygous Germline <i>NF1</i> Pathogenic Variants

Neurofibromatosis 1 (NF1) is one of the most common genetic diseases of the central nervous system. The nature of intracranial lesions that are associated with NF1 are yet to be fully defined. Arachnoid, velum interpositum, and odontogenic cysts are among the more common intracranial cystic lesions that can be congenital. Although odontogenic cysts are well known to be associated with Gorlin-Goltz syndrome, the possibilities of other genetic disorders in patients with odontogenic and other intracranial cystic lesions have continued to stir research interests. Here, we report 2 cases of unrelated patients, each patient having concurrent intracranial cystic lesions in the setting of a diagnosis of NF1. Individual I had concomitant arachnoid and odontogenic cysts in parallel with a novel heterozygous germline <i>NF1</i> pathogenic frameshift variant, <i>NF1</i> [NM_000267.3] c.40del (p.Val14Serfs*10). Individual II had concomitant arachnoid and vellum interpositum cysts in the context of a heterozygous likely pathogenic <i>NF1</i> germline variant [<i>NF1</i> (NM_000267.3) c.4265C>T, p.(Ser1422Leu)]. Our observations suggest that clinicians should consider NF1 among the differential diagnosis for intracranial cystic lesions such as arachnoid, vellum interpositum, and odontogenic cysts.