Usefulness of neuroimaging and immunohistochemical study for accurate diagnosis of parasagittal hemangioblastoma arising in the supratentorial region: a case report and review of the literature.

Background: Hemangioblastoma originates in the central nervous system (CNS), usually in the cerebellum, and sporadic cases in the supratentorial region are extremely rare. In addition, there have been no previous reports of cases showing hyperintensity on diffusion weighted image (DWI) on magnetic resonance imaging (MRI) and negative immunostaining for inhibin-alpha. Here, we report a rare case of sporadic supratentorial hemangioblastoma arising in the parasagittal region and suggest a useful indicator for the exact diagnosis and pitfalls for surgical procedures.

Case Description: A 66-year-old woman was admitted to our hospital with a 6-month history of progressive numbness in the right lower extremities and gait disturbance. Neurological findings on admission revealed mild right-sided hemiparesis of the lower limbs (manual muscle test: 4/V). Neuroimaging demonstrated an abnormal lesion with clear boundaries in the left frontal lobe appearing hypointense on T1-weighted image (WI), hyperintense on T2-WI, and hyperintense on DWI, with strong enhancement on gadolinium (Gd)-enhanced T1-WI. Computed tomography (CT) showed no calcification, and cerebral angiography revealed strong staining from bilateral middle meningeal arteries and the left anterior cerebral artery (ACA). Surgical excision of the lesion was performed and gross total resection was achieved. Histological findings revealed a marked increase in vascular structures, and the round stroma contained tumor cells. Silver impregnation stains demonstrated abundant reticulin fibers. In addition, immunohistochemistry revealed that most tumor cells stained negatively for epithelial membrane antigen (EMA) and inhibin-alpha, and positively stained for podoplanin (D2-40), and the tumor was diagnosed as hemangioblastoma. The postoperative course was uneventful and follow-up neuroimaging after one year revealed no signs of recurrence.

Conclusions: Supratentorial hemangioblastomas are extremely rare and display a strong infiltrative and aggressive nature. Careful identification from preoperative image and histopathological study for appropriate treatment selection are warranted for supratentorial hemangioblastoma.