Jugular foramen schwannoma case series

Kim et al. .aimed to investigate the incidence, clinical features, and mid-term outcomes of early-onset adverse events occurring within six months after stereotactic radiosurgery for jugular foramen schwannoma.

Methods: In this retrospective review, patients who underwent at least six months of follow-up were included among all patients with JFS who have performed SRS at our institution between July 2008 and November 2019. And eAEs were defined as a newly developed neurological deficit or aggravation of pre-existing symptoms during the first six months after SRS.

Results: Forty-six patients were included in the analysis. The median follow-up period was 50 months (range 9-136). The overall tumor control rate was 91.3%, and the actuarial 3-, 5-, and 10-year progression-free survival rates were 97.8%, 93.8%, and 76.9%, respectively. Of the 46 patients, 16 had eAEs, and the median time to onset of eAEs was one month (range 1-6 months), and the predominant symptoms were lower cranial nerve dysfunctions. Thirteen of 16 patients showed improved eAE symptoms during the follow-up period, and the median resolution time was six months (range 1-52). In 11 (68.8%) of 16 patients with eAEs, transient expansions were observed with a mean of 3.6 months after the onset of eAEs, and the mean difference between the initial tumor volume and the transient expansion volume was more prominent in the patients with eAEs (3.2 cm3 vs. 1.0 cm3; p = 0.057). In univariate analysis, dumbbell-shaped tumors (OR 10.56; p = 0.004) and initial tumor volume (OR 1.32; p = 0.033) were significantly associated with the occurrence of eAEs.

Conclusions: Although acute adverse events after SRS for JFS are not rare, these acute effects were not permanent and mostly improved with the steroid treatment. Dumbell-shaped and large-volume tumors are significant predictive factors for the occurrence of eAEs. And the transient expansion also seems to be closely related to eAEs. Therefore, clinicians need to be more cautious when treating these patients and closely monitor the occurrence of eAEs. ¹⁾.

Between November 2011 and November 2017, 31 consecutive patients diagnosed with jugular foramen schwannoma underwent a single-stage operation performed by the same neurosurgeon. Wang et al. retrospectively analyzed clinical characteristics, surgical approaches, treatment outcomes, and follow-up data for these patients. JFSs were classified according to the Samii Jugular foramen schwannoma classification system. A retrosigmoid approach was used to resect type A tumors, while a suboccipital transjugular process (STJP) approach was used to resect type B tumors. Notably, the present study is the first to report the use of a paracondylar-lateral cervical (PCLC) approach for the treatment of type C and D tumors. Type A-D tumors were observed in seven, four, four, and 16 patients, respectively. Gross-total resection was achieved in 29 patients (93.5%). There were no cases of intracranial hematoma, re-operation, tracheotomy, or death. Adjunctive gamma knife treatment was used to manage residual tumors in two patients. Neurological deficits relieved in half of patients at the last follow-up. By reviewing the studies published on PubMed, the approaches gradually be more conservative, rather than widely expose the skull base. Nonetheless, endoscope and stereotactic radiosurgery plays an important role in the management of JFSs. Both tumor removal and neurological function retention can be obtained by choosing individual treatment ²⁾.

A multiinstitutional retrospective analysis of 117 patients with JFSs who were treated with Gamma Knife surgery (GKS) at 18 medical centers of the Japan Leksell Gamma Knife Society. The median age of the patients was 53 years.

Fifty-six patients underwent GKS as their initial treatment, while 61 patients had previously undergone resection. At the time of GKS, 46 patients (39%) had hoarseness, 45 (38%) had hearing disturbances, and 43 (36%) had swallowing disturbances. Eighty-five tumors (73%) were solid, and 32 (27%) had cystic components. The median tumor volume was 4.9 cm3, and the median prescription dose administered to the tumor margin was 12 Gy. Five patients were treated with fractionated GKS and maximum and marginal doses of 42 and 21 Gy, respectively, using a 3-fraction schedule.

The median follow-up period was 52 months. The last follow-up images showed partial remission in 62 patients (53%), stable tumors in 42 patients (36%), and tumor progression in 13 patients (11%). The actuarial 3- and 5-year progression-free survival (PFS) rates were 91% and 89%, respectively. The multivariate analysis showed that pre-GKS brainstem edema and dumbbell-shaped tumors significantly affected PFS. During the follow-up period, 20 patients (17%) developed some degree of symptomatic deterioration. This condition was transient in 12 (10%) of these patients and persistent in 8 patients (7%). The cause of the persistent deterioration was tumor progression in 4 patients (3%) and adverse radiation effects in 4 patients (3%), including 2 patients with hearing deterioration, 1 patient with swallowing disturbance, and 1 patient with hearing deterioration and hypoglossal nerve palsy. However, the preexisting hoarseness and swallowing disturbances improved in 66% and 63% of the patients, respectively.

GKS resulted in good tumor control in patients with either primary or residual JFSs. Although some patients experienced some degree of symptomatic deterioration after treatment, persistent adverse radiation effects were seen in only 3% of the entire series at the last follow-up. Lower cranial nerve deficits were extremely rare adverse radiation effects, and preexisting hoarseness and swallowing disturbances improved in two-thirds of patients. These results indicated that GKS was a safe and reasonable alternative to surgical resection in selected patients with JFSs ³⁾.

Sixteen consecutive patients with JFSs were retrospectively evaluated. Tumor extension was classified using a modification of a previous classification of Samii, and surgical approach was selected accordingly. The extent of tumor resection, cranial nerve outcome, approach-related morbidities, and recurrence of the tumors were documented.

Four cases of JFSs were subtotally resected elsewhere and 12 were primary. The most common type was B2 (6 cases). The average tumor size was 38.5 mm. Gross total resection was achieved in all patients, and none recurred during follow-up. There was no operative mortality or new permanent neurological deficits. A postoperative cerebrospinal fluid leak developed in 2 patients, 1 managed with lumbar drain and the other with wound revision. The preoperative swallowing difficulty temporarily deteriorated in 3 patients, but recovered well within the first 2 postoperative weeks in all 3. Improvement of the preoperative lower cranial nerve dysfunction was observed in 5 patients ⁴⁾.

Ten patients with jugular foramen schwannomas treated by the senior author between January 2007 and December 2012. Three patients had undergone partial tumour resection elsewhere. The initial symptom for which they sought medical help was hearing loss, dysphagia, hoarseness, and shoulder weakness. Preoperative glossopharyngeal and vagal nerve deficits were the most common signs. In the series, tumour extension was classified according to Kaye-Pellet grading system. In two cases the tumours were classified into type A and 8 patients presented with type D tumours. A retromastoid suboccipital craniotomy was performed for type A tumours and modifications of cranio-cervical approach were suitable for type D.

No death occurred in this series. Four patients deteriorated after surgery: in two patients preoperative cranial nerve deficits deteriorated after surgery while new cranial nerve palsy occurred in 2 other patients. In four patients, the cranial nerve dysfunction had improved at the last follow-up examination. In all other patients, the cranial nerve dysfunction remained the same. One patient experienced tumour recurrence over a follow-up period of 40 months. This patient underwent a successful second surgery without further evidence of tumour growth ⁵⁾.

23 patients. One patient (a 73-year-old woman) with normal lower cranial nerves function was managed with watchful expectancy and regular clinical and radiologic follow ups. The infratemporal fossa approach-type A (IFTA-A) was performed in 3 cases. One patient underwent a transcochlear-transjugular approach. Of the 22 patients surgically treated, 12 patients were operated on by the petrooccipital transsigmoid approach (POTS). In one patient with a preoperative dead ear, a combined POTS-translabyrinthine approach was adopted. Two patients were operated on through the POTS approach combined with the transotic approach. In another case (a 67-year-old woman), a subtotal tumor removal through a transcervical approach was planned to resect a 10-cm mass in the neck. One patient underwent a first-stage combined transcervical-subtotal petrosectomy approach to remove a huge tumor in the neck; the second-stage intradural removal of the tumor was accomplished through a translabyrinthine-transsigmoid-transjugular approach. The last patient underwent a first-stage combined transcervical-subtotal petrosectomy approach to remove the neck tumor component; this patient is now waiting for the second-stage intradural removal of the tumor. Complete tumor removal was accomplished in 21 cases and in one case, a residual schwannoma was left in place in the area of the jugular foramen. The 3 patients who were operated on by IFTA-A underwent permanent anterior transposition of the facial nerve. At 1-year follow up, 2 of these patients had House-Brackmann grade I and 1 reached grade IV. The patient who underwent a transcochlear-transjugular approach had a permanent posterior transposition of the facial nerve. At 1-year follow up, he had grade III facial nerve function. Postoperative facial nerve function was normal (House-Brackmann grade I) in all patients operated on by the POTS approach. Twelve patients had hearing-preserving surgery using the POTS approach. Good hearing was preserved in 10 cases (83.3%), the majority of whom (58.3%) maintained their preoperative hearing level. There was no perioperative mortality. One patient (4.5%) experienced a postoperative cerebrospinal fluid leak. After surgery, all patients did not recover the function of the preoperatively paralyzed lower cranial nerves. A new deficit of one or more of the lower cranial nerves was recorded in 50% of cases. So far, no patient has experienced recurrence during the follow-up period as ascertained by computed tomography or magnetic resonance imaging.

Surgical resection is the treatment of choice for jugular foramen schwannomas. The POTS approach allowed single-stage, total tumor removal with preservation of the facial nerve and of the middle and inner ear functions in the majority of cases. Despite the advances in skull base surgery, new postoperative lower cranial nerve deficits still represent a challenge ⁶⁾.