OBJECTIVETo improve the diagnosis and treatment of hypoglossal neurilemmoma (HGN).

METHODSThe data of 10 patients with HGN were retrospectively reviewed, 5 of 10 patients (early group) had been reported previously. A comparison of treatment strategy between early and latter group was made.

RESULTSTypical hemiatrophy of the tongue presented in all 10 patients, hypoglossal canal could be showed in the bone window of CT, which, however, might not confirm the existence of tumor if it is very small. MRI was the optical choice for diagnosis. Among the early 5 cases with HGN which were all of dumbbell type, the intracranial part and the extracranial part of the tumor in 2 cases were removed by stages, 3 cases were operated via the far-lateral approach, of which 1 was via trans-condylar approach and 2 were via trans-supracondylar approach; the 5 tumors were removed subtotally except 1 totally; CSF leakage and intra-cranial infection after operation occurred in 1 case; the rating of Karnofsky Prognosis Scale was good in 4 cases and dead in 1 case. However, among the latter 5 cases, 4 cases including 2 of dumbbell type, 1 of intra-cranial type and 1 of intracanal type were operated via the modified far-lateral approach, of which 1 was via trans-condylar approach and 3 were via trans-supracondylar approach; and the tumor of extracranial type in the last case was resected twice via transcervical approach, being removed subtotally in the first operation followed by total removal with the aid of neuronavigation and neuroendoscopy in the second operation when it failed to react to the treatment of gamma knife; the 5 tumors were removed totally except 1 subtotally.; all postoperative courses were uneventful.; follow up was performed successfully in 4 cases, the rating of Karnofsky Prognosis Scale was excellent in 3 cases and fair in 1 case. The outcomes of the latter 5 cases resected via modified approach were better than those of the early 5 cases.

CONCLUSIONHGN is extremely rare and it is difficult to treat it. To achieve a good operative outcome, it is very important to design the approach individually based on its location and size and operate mini-invasively and resect tumor totally as possible as can in the primary stage.