Coexistence of meningioma and craniofacial fibrous dysplasia: a case series of clinicopathological study and literature review.

The co-existence of meningioma and craniofacial fibrous dysplasia (CFD) is rare. Due to the similar radiological characteristics, it is challenging to differentiate such co-existence from solitary hyperostotic meningioma resulting in a dilemma of prompt diagnosis and appropriate intervention. We conducted a retrospective review of the data from 21 patients with concomitant meningioma and CFD who were treated at Beijing Tiantan Hospital from 2003 to 2021. We summarized their clinicopathological features and performed a comprehensive literature review. Additionally, we tested the characteristic pathogenic variants in exon 8 and 9 of GNAS gene and the expression of corresponding α-subunit of the stimulatory G protein (Gαs) related to CFD to explore the potential interactions between these two diseases. The cohort comprised 4 men and 17 women (mean age, 45.14 years). CFD most commonly involved the sphenoid bone (n = 10) and meningiomas were predominantly located at the skull base (n = 12). Surgical treatment was performed in 4 CFD lesions and 14 meningiomas. Simpson grade I-II resection was achieved in 12 out of the 14 resected meningiomas and almost all of them were classified as WHO I grade (n = 13). The mean follow-up duration was 56.89 months and recurrence was noticed in 2 cases. Genetic study was conducted in 7 tumor specimens and immunohistochemistry was accomplished in 8 samples showing that though GNAS variant was not detected, Gαs protein were positively expressed in different degrees. We presented an uncommon case series of co-diagnosed meningioma and CFD and provided a detailed description of its clinicopathological features, treatment strategy and prognosis. Although a definite causative relationship had not been established, possible genetic or environmental interplay between these two diseases could not be excluded. It was challenging to initiate prompt diagnosis and appropriate treatment for concomitant meningioma and CFD because of its similar radiological manifestations to meningioma with reactive hyperostosis. Personalized and multi-disciplinary management strategies should be adopted for the co-existence of meningioma and CFD.