A case of Maffucci syndrome with a buccal hemangioma harboring a mutation in IDH1.

Maffucci syndrome, first described in 1881, is a rare, non-hereditary skeletal disorder characterized by multiple enchondromas in combination with soft tissue hemangiomas. Recent studies have implicated somatic mutations in IDH1/2 contributing to the pathogenesis of Maffucci syndrome. This study describes the first case of Maffucci syndrome harboring a mutation in IDH1, which was associated with a hemangioma in the oral mucosa. A 32-year-old man, who was diagnosed with Maffucci syndrome during childhood, was referred to our department in April 2020 due to a mass in the left buccal mucosa. The mass was soft, dome-shaped, had dark red protrusions and well-defined borders, and the dimensions were approximately 15 × 10 mm. Magnetic resonance imaging revealed a mass with a dimension of 13 × 10 mm, which appeared hyperintense on T2-weighted images. The vascular lesion was surgically resected under local anesthesia owing to hemangioma diagnosis. We then analyzed the IDH1/2 sequences using DNA extracted from the excised tumor tissue and peripheral blood. The analysis revealed the presence of a heterozygous mutation in IDH1 in the tumor tissue, corresponding to an R132C substitution. The mutation was not present in peripheral blood DNA. After over one year of resection, the patient is presently free from tumor recurrence and is under follow-up for the early detection of recurrent hemangioma.