Tuberous sclerosis complex and sphenoid meningioma

Somatic mutation landscape in a cohort of meningiomas that have undergone grade progression

BACKGROUND

A subset of meningiomas progress in histopathological grade but drivers of progression are poorly understood. We aimed to identify somatic mutations and copy number alterations (CNAs) associated with grade progression in a unique matched tumour dataset.

METHODS

Utilising a prospective database, we identified 10 patients with meningiomas that had undergone grade progression and for whom matched pre- and post-progression tissue (n = 50 samples) was available for targeted next-generation sequencing.

RESULTS

Mutations in NF2 were identified in 4/10 patients, of these 94% were non-skull base tumours. In one patient, three different NF2 mutations were identified in four tumours. NF2 mutated tumours showed large-scale CNAs, with highly recurrent losses in 1p, 10, 22q, and frequent CNAs on chromosomes 2, 3 and 4. There was a correlation between grade and CNAs in two patients. Two patients with tumours without detected NF2 mutations showed a combination of loss and high gain on chromosome 17q. Mutations in SETD2, TP53, TERT promoter and NF2 were not uniform across recurrent tumours, however did not correspond with the onset of grade progression.

CONCLUSION

Meningiomas that progress in grade generally have a mutational profile already detectable in the pre-progressed tumour, suggesting an aggressive phenotype. CNA profiling shows frequent alterations in NF2 mutated tumours compared to non NF2 mutated tumours. The pattern of CNAs may be associated with grade progression in a subset of cases.

Innumerable Meningiomas Arising in a Patient With Tuberous Sclerosis Complex Decades After Radiation Therapy

Meningioma is the most common radiation-induced brain neoplasm, usually occurring after a latency of 20 - 35 years, with multiplicity in 10% of cases. Radiation-induced meningiomas (RIMs) have not previously been reported in patients with tuberous sclerosis complex (TSC), unlike their well-known occurrence in other familial tumor predisposition syndrome patients. We report a TSC patient who developed numerous intracranial meningiomas twenty five year after radiation therapy for subependymal giant cell astrocytoma (SEGA). Autopsy examination showed innumerable, coalescent, benign, meningothelial meningiomas, WHO grade 1, ranging in size from 0.2 cm to 3.3 cm. Autopsy also showed small residual SEGA, radiation-induced cerebral vasculopathy, and classic TSC features including several small subependymal nodules ("candle gutterings"), white matter radial heterotopia, facial angiofibromas, dental enamel pitting, one ash leaf spot, and multiple hepatic and renal angiomyolipomas. Next-generation sequencing analysis utilizing a 500+ gene cancer panel demonstrated chromosomal loss involving the majority of chromosome 22, including the NF2 gene locus, as well as a truncating nonsense mutation in TSC1 p. R509*. While TSC patients rarely require radiation therapy, this striking case suggests that patients with TSC should be monitored closely if cranial therapeutic radiation is administered.

Manifestations of Tuberous Sclerosis Complex: The Experience of a Provincial Clinic

BACKGROUND

Tuberous sclerosis complex (TSC) is a neurocutaneous disorder with a wide spectrum of manifestations. Recent consensus recommendations stress the importance of multidisciplinary management of children with TSC. The objective of this study was to examine the manifestations of TSC at a large referral centre to determine the care needs of this population.

METHODS

A retrospective, systematic chart review was performed of children with TSC managed at British Columbia Children's Hospital. Patients were identified through epilepsy and clinical neurophysiology databases.

RESULTS

The study population comprised 81 patients, born between 1987 and 2014, who were a median of 10 years (range, 0.2-23.2) at most recent follow-up. Epilepsy occurred in 91% of patients, including 32% with a history of infantile spasms. Nineteen patients underwent epilepsy surgery, nine (47%) of whom were seizure-free at most recent follow-up. Overall, 61% of epilepsy patients had been seizure-free for at least 1 year at the time of last follow-up. Neuropsychiatric disorders were diagnosed in 49% of children, with autism (25%), attention deficit hyperactivity order (19%) and anxiety (16%) being the most common. Cardiac rhabdomyomata occurred in 35% of children and renal angiomyolipomas were seen in 43%. A total of 91% had skin manifestations.

CONCLUSION

This study outlines the multisystem manifestations of TSC, observed through a large pediatric referral center. Epilepsy and neuropsychiatric disorders are the major source of morbidity in this age group and provide many challenges to the treating clinician. Because a subset of the study population is still quite young, the prevalence of neuropsychiatric disorders is likely underestimated.

Glioblastoma Secondary to Meningioma: A Case Report and Literature Review

BACKGROUND

The pathophysiologies underlying meningioma and glioma are distinct. The coexistence of those 2 lesions in the same patient is rare, and at the same location, it is even more exceptional.

CASE DESCRIPTION

We report a case of a 79-year-old man initially presenting with a meningioma that was treated by complete excision of the lesion. The patient had 2 relapses at the same site, in which glioblastoma was confirmed histopathologically.

CONCLUSIONS

Glial transformation meningiomas remain a contentious issue, with coincidental occurrence being the most prevalent explanation. Nevertheless, impairment of the same molecular signaling pathways in both tumor types suggests a common origin. Another hypothesis is that perilesional parenchymal damage from radiotherapy or surgery may lead to glial transformation in the tissues surrounding the original meningioma lesion. Further research is needed to determine if the original tumor or surgery has an oncogenic effect on the adjacent tissue.