An ancient schwannoma with venous malformation-like features of the tongue A case report and review of the literature

Rationale: Composite lesions of neurogenic tumors with vascular malformations, which were once included among hemangiomas, are extremely rare and can be classified into 2 types: conjoined and discrete associations, with the former representing a single lesion of vascular malformation within tumor tissue. To date, we have found 24 composite lesions (conjoined association type) of schwannomas coexisting with vascular malformations. However, such composite lesions should be interpreted with caution. Patient concerns: A 29-year-old woman had recognized swelling of the tongue 5 years prior to her initial hospital visit and the lesion had recently been slowly growing. Diagnoses: Based on clinical examinations, including imaging studies, the tumorous lesion was clinically diagnosed as a schwannoma, but a benign salivary gland tumor and venous malformation (VM) were not completely ruled out. Interventions: The lesion was excised with safety margin. Outcomes: The excised sample revealed 2 intriguing features; however, the lesion was diagnosed as an ancient schwannoma with VM-like features because of the lack of definitive findings that would make these lesions a composite of independent lesions. There was no evidence of recurrence or distant metastasis at the 16-month follow-up after excision. Lessons: Ancient schwannomas of the oral cavity are rare. In particular, schwannomas that appear as composite lesions of schwannomas with vascular malformations are extremely rare. Here, we report the first case of an ancient schwannoma with VM-like features of the tongue. It is important for clinicians to accumulate information on these rare cases to make an accurate preoperative diagnosis and to plan appropriate treatment. Abbreviations: CNB = core needle biopsy, FNA = fine-needle aspiration, MRI = magnetic resonance imaging, US = ultrasonography, VM = venous malformation.