Grading System and Surgical Strategy for Temporal Bone Diffuse-Type Tenosynovial Giant Cell Tumor.

OBJECTIVES: To develop a novel grading system and appropriate surgical approaches for patients with diffuse type tensosynovial giant cell tumor (D-TGCT) of the temporal bone. STUDY DESIGN: Retrospective cohort study. METHODS: We retrospectively reviewed 31 patients with temporal bone D-TGCT between June 2012 and July 2021. All patients underwent comprehensive clinical evaluations, including clinical presentations, hearing threshold, imaging studies, surgical approaches, and prognosis. A grading system was developed based on the tumor location and adjacent neurovascular structures involvement according to imaging and intraoperative findings. RESULTS: In this study, grade II tumors were the most common (13/31), followed by grades I (7/31), III (7/31), and IV (4/31) tumors. Seven grade I patients received the subtemporal middle cranial fossa approach (SMCF) combined with the canal wall up mastoidectomy and tympanoplasty (CWUT). Nine grade II patients underwent SMCF combined with subtotal petrosectomy (SPTR), and four grade II patients underwent SMCF combined with CWUT. Seven grade III patients received SMCF combined with SPTR and dura mater reconstruction, and four grade IV patients underwent infratemporal fossa approach type B. Gross total resection was achieved in all patients, and the median follow-up time was 30.1 months (range, 4-96 months). Three patients (one grade II, one grade III, and one grade IV) had recurrence during follow-up, and the patient with grade III tumor had two recurrences. CONCLUSIONS: Gross total resection is the first-line treatment for patients with D-TGCT of the temporal bone. This novel grading system enables surgeons to select optimal surgical strategy. Long-term follow-up is mandatory postoperatively. LEVEL OF EVIDENCE: 4 Laryngoscope, 132:1275-1284, 2022.

A novel grading system for the prediction of the need for cerebrospinal fluid drainage following posterior fossa tumor surgery.

OBJECTIVE: Prophylactic placement of an external ventricular drain (EVD) is often performed prior to resection of a posterior fossa tumor (PFT); however, there is no general consensus regarding the indications. The purpose of this study was to establish a novel grading system for the prediction of required CSF drainage due to symptomatic elevated intracranial pressure (ICP) after resection of a PFT to identify patients who require an EVD. METHODS: The authors performed a retrospective analysis of data from a prospective database. All patients who had undergone resection of a PFT between 2012 and 2017 at the University Hospital, Goethe University Frankfurt, were identified and data from their cases were analyzed. PFTs were categorized as intraparenchymal (iPFT) or extraparenchymal (ePFT). Prior to resection, patients underwent EVD placement, prophylactic burr hole placement, or neither. The authors assessed the amount of CSF drainage (if applicable), rate of EVD placement at a later time point, and complication rate and screened for factors associated with CSF drainage. By applying those factors, they established a grading system to predict the necessity of CSF drainage for elevated ICP. RESULTS: A total of 197 patients met the inclusion criteria. Of these 197, 70.6% received an EVD, 15.7% underwent prophylactic burr hole placement, and 29.4% required temporary CSF drainage. In the prophylactic burr hole group, 1 of 32 patients (3.1%) required EVD placement at a later time. Independent predictors for postoperative need for CSF drainage due to symptomatic intracranial hypertension in patients with iPFTs were preoperative hydrocephalus (OR 2.9) and periventricular CSF capping (OR 2.9), whereas semi-sitting surgical position (OR 0.2) and total resection (OR 0.3) were protective factors. For patients with ePFTs, petroclival/midline tumor location (OR 12.2/OR 5.7), perilesional edema (OR 10.0), and preoperative hydrocephalus (OR 4.0) were independent predictors of need for CSF drainage. According to our grading system, CSF drainage after resection of iPFT or ePFT, respectively, was required in 16.7% and 5.1% of patients with a score of 0, in 21.1% and 12.5% of patients with a score of 1, in 47.1% and 26.3% of patients with a score of 2, and in 100% and 76.5% of patients with a score ≥ 3 (p < 0.0001). The rate of relevant EVD complications was 4.3%, and 10.1% of patients were shunt-dependent at 3-month follow-up. CONCLUSIONS: This novel grading system for the prediction of need for CSF drainage following resection of PFT might be of help in deciding in favor of or against prophylactic EVD placement.