Brain stem angioleiomyoma mimicking meningioma: a case report

Angioleiomyoma is a benign lesion of mesenchymal origin, which always occurs in the uterine system. Pathologically, angioleiomyoma is usually composed of well-differentiated smooth muscle cells with few mitotic features. However, primary intracranial angioleiomyoma represents an exceedingly rare tumor, since the first case reported in 1994.

Here, we reported a case of primary intracranial angioleiomyoma, which mimicking meningioma in pre-operative images. The patient was a 42-year-old male, presented with dizziness and unsteady walking for about 6 months, without symptoms of cranial nerve deficit. Head computer tomography scan showed a well-defined lesion adjacent to right brain stem with high intensity. Contrast brain magnetic resonance imaging (MRI) scan exhibited an extra-axial mass with homogeneous enhancement located at the right pontine, presented as meningioma features; however, other tumors including lymphoma should be differentiated as well. The patient underwent sub-temporal craniotomy for the tumor resection. Histological analysis confirmed the diagnosis of angioleiomyoma. Follow-up brain MRI scan (6 months after surgery) showed total resection of the lesion without residual.

In summary, primary intracranial angioleiomyoma is rare. Thus, diagnosis and differential diagnosis are important before surgical resection, which was mimicking meningioma in our case. Pathological analysis could reveal spindle shaped cells with few mitotic features, and confirm the diagnosis of angioleiomyoma. Currently, the optimal therapy for primary intracranial angioleiomyoma is surgical resection, and adjuvant radiation therapy for the residual tumor. However, long-term prognosis of the disease should be monitor in the future.