Surgical treatment of dumbbell-shaped hypoglossal schwannoma via a pure endoscopic transoral approach.

BACKGROUND

Dumbbell-shaped hypoglossal schwannomas with intradural and extradural extension are extremely rare, and complete removal of these tumors is very difficult. This report describes such lesions in three patients that were completely removed via a purely endoscopic transoral approach.

METHOD

Three patients with intradural and extradural growth hypoglossal schwannomas (three women, aged 16, 42 and 43 years) were treated by direct surgery via a purely endoscopic transoral approach to the posterior fossa.

RESULTS

In this series, radical resections of the dumbbell-shaped hypoglossal schwannomas were achieved in all three patients via a purely endoscopic transoral approach without creating additional cranial nerve deficits but temporary left vagus palsy in one case and a temporary left hypoglossal palsy in one case. The postoperative vagus and hypoglossal palsy had recovered in 3 months after surgery. No patient experienced complications such as postoperative cerebrospinal fluid leak, meningitis and cerebrovascular evidence. At the time of this review, the preoperative lingual motor function and muscular bulk had recovered but hemiatrophy of the tongue was still detectable. The preoperative vagus palsy had recovered by the 10th day after surgery. The hearing loss and facial palsy before surgery had completely recovered in 3 months postoperatively. No patient in our series has experienced a recurrence for the follow-up period (3-11 months).

CONCLUSIONS

Dumbbell-shaped hypoglossal schwannomas tend to cause lower cranial nerve deficits, facial paralysis and hearing loss. With appropriate preoperative evaluation and careful planning of the perioperative period, complete tumor resection can be achieved via the purely endoscopic transoral approach. The endoscopic transoral approach is an effectice choice for management of dumbbell-shaped hypoglossal schwannomas.