Spinner, Robert J.

Abstract BACKGROUND Synovial sarcoma of the nerve is a rare entity with several cases and case series reported in the literature. Despite an improved understanding of the biology, the clinical course is difficult to predict. OBJECTIVE To compile a series of patients with synovial sarcoma of the peripheral nerve (SSPN) and assess clinical and pathological factors and their contribution to survival and recurrence. METHODS Cases from 2 institutions collected in patients undergoing surgical intervention for SSPN. Systematic review including PubMed and Scopus databases were searched for related articles published from 1970 to December 2018. Eligibility criteria: (1) case reports or case series reporting on SSPN, (2) clinical course and/or pathological features of the tumor reported, and (3) articles published in English. RESULTS From patients treated at our institutions (13) the average follow-up period was 3.2 yr. Tumor recurrence was seen in 4 cases and death in 3. Systematic review of the literature yielded 44 additional cases with an average follow-up period of 3.6 yr. From pooled data, there were 10 recurrences and 7 deaths (20% and 14%, respectively). Adjuvant treatment used in 62.5% of cases. Immunohistochemical markers used in diagnosis varied widely; the most common are the following: Epithelial membrane antigen (EMA), cytokeratin, vimentin, cluster of differentiation (CD34), and transducin-like enhancer of split 1 (TLE1). Statistical analysis illustrated tumor size and use of chemotherapy to be negative predictors of survival. No other factors, clinically or from pathologist review, were correlated with recurrence or survival. CONCLUSION By combining cases from our institution with historical data and performing statistical analysis we show correlation between tumor size and death.

Background: Interfascicular resection is a surgical technique used to safely treat benign peripheral nerve sheath tumors through careful dissection of functional neural elements off the tumor surface 1,2 . Description: Proper operative technique is essential to improving symptoms, preserving neurologic function, and minimizing the chance for recurrence. Accurate tumor localization, ideal patient positioning, and placement of a longitudinal incision permit adequate exposure. Prior to tumor resection, normal nerve should be identified proximally and distally and controlled with vessel loops. This allows functional fascicles streaming around the tumor in the pseudocapsule to be visualized during resection. A fascicle-free window is identified on the tumor surface through visual inspection and intraoperative neurophysiology monitoring if desired. The pseudocapsule layers are divided with a sharp instrument until a smooth and shiny true capsule layer is found. This plane should have minimal resistance and is developed circumferentially until the tumor can be enucleated in toto. At the poles of the tumor, a single nonfunctional nerve fascicle that courses into the tumor is typically found. If there is >1 fascicle running into the tumor, further pseudocapsule layers should be undermined to sweep fascicles off the true capsule surface. The entering-exiting fascicle can be tested for function and is cut sharply. The specimen should be sent to pathology for permanent sectioning. The sides of the pseudocapsule are spread in opposite directions to evaluate for residual tumor, and any remaining tumor is removed if it can be done safely. Meticulous hemostasis is achieved, and the surgical site is closed in anatomical layers. Alternatives: Pain is the most common presenting symptom, and neuroleptic medications should be used in escalating dosage prior to surgical intervention. Nonoperative medical therapy does not typically result in symptom freedom, and patients often opt for resection. For tumors that are suspected of being malignant, an image-guided percutaneous or open biopsy and staging (positron emission tomography and/or computed tomography scans of the chest, abdomen, and pelvis) are recommended prior to treatment planning. For symptomatic benign extremity lesions, surgical resection is the treatment of choice, and adjuvant therapies like radiation and/or chemotherapy are not recommended. For malignant lesions, more aggressive surgery (wide resection or amputation) and preoperative, intraoperative, or postoperative radiation with or without chemotherapy are often utilized. Rationale: The treatment approach depends on a variety of presenting features such as onset, progression, symptom severity, tumor size, location, imaging features, presence of a syndrome, and patient age. There is little benefit from the resection of an incidentally found, small, nongrowing lesion. The most common reasons for removal of extremity lesions are a painful mass and/or radiating “nerve” pain. There is a high likelihood of relieving the symptoms and minimizing the risk of recurrence, and a relatively low risk of causing neurologic injury. The procedure provides a definitive diagnosis. For patients with severe pain, progressive weakness, rapid tumor growth, or concerning imaging characteristics, biopsy should be considered to determine malignant potential.

We sought to identify predictors of failed ulnar nerve fascicle (to flexor carpi ulnaris) to biceps motor branch transfer. A retrospective review of adult brachial plexus patients treated with flexor carpi ulnaris to biceps transfer with a minimum 1-year follow-up was performed. Failure, defined as modified British Medical Research Council grade <3 elbow flexion was compared with randomly selected controls (M ≥ 4−). Ninety-one patients, of which 80% regained >M3 flexion met criteria. Eighteen failures and 18 controls, with similar follow-up (20 vs 23 months) were evaluated. Preoperative flexor carpi ulnaris weakness (M < 5) was significantly more common in failures (78% vs 33%). The rate of flexor carpi ulnaris recovery after operation was significantly higher in controls (86% vs 7%). Increased failure risk can be expected with impaired preoperative flexor carpi ulnaris function. The challenge is how to identify which patients will regain near normal flexor carpi ulnaris strength as excellent outcomes can be obtained. Level of evidence: III

Abstract BACKGROUND Intraneural ganglion cysts are joint-connected, with the primary pathology residing in the associated joint. For peroneal intraneural ganglion cysts, the surgical strategy can include resection of the synovial surface of the superior tibiofibular joint (STFJ). However, the rate of instability postoperatively is unclear. OBJECTIVE To evaluate the rate of STFJ instability, following surgery for peroneal intraneural ganglion cysts. The second goal of the study was to assess the relationship between volume of resection of the STFJ and risk of extraneural recurrence. METHODS We performed a retrospective analysis of a cohort of patients with peroneal intraneural ganglion cysts. We analyzed clinical factors, including recurrence, and assessed the rate of postoperative STFJ instability. We created 3-dimensional models of the STFJ pre- and postoperatively to compare the volume of resection in recurrent cases and nonrecurrent cases using a case-control design. RESULTS The total cohort consisted of 65 subjects. No patient had evidence of radiological or clinical instability of the STFJ postoperatively. Extraneural radiological recurrence occurred in 6 (9%) patients. No intraneural recurrences were observed. The average volume of resection for patients with recurrence was 1349 mm 3 (SD = 1027 mm 3 ) vs 3018 mm 3 (SD = 1433 mm 3 ) in controls that did not have a recurrence ( P = .018). CONCLUSION This study supports performing an aggressive STFJ resection to minimize the risk of extraneural recurrence. Superior tibiofibular joint resection is not associated with postoperative joint instability. A smaller volume resection is correlated with recurrence risk.

OBJECTIVESpinal peripheral nerve sheath tumors (PNSTs) are a group of rare tumors originating from the nerve and its supporting structures. Standard surgical management typically entails laminectomy with or without facetectomy to gain adequate tumor exposure. Arthrodesis is occasionally performed to maintain spinal stability and mitigate the risk of postoperative deformity, pain, or neurological deficit. However, the factors associated with the need for instrumentation in addition to PNST resection in the same setting remain unclear.METHODSAn institutional tumor registry at a tertiary care center was queried for patients treated surgically for a primary diagnosis of spinal PNST between 2002 and 2016. An analysis focused on patients in whom a facetectomy was performed during the resection. The addition of arthrodesis at the index procedure comprised the primary outcome. The authors also recorded baseline demographics, tumor characteristics, and surgery-related variables. Logistic regression was used to identify factors associated with increased risk of fusion surgery.RESULTSA total of 163 patients were identified, of which 56 (32 had facetectomy with fusion, 24 had facetectomy alone) were analyzed. The median age was 48 years, and 50% of the cohort was female. Age, sex, and race, as well as tumor histology and size, were evenly distributed between patients who received facetectomy alone and those who had facetectomy and fusion. On univariate analysis, total versus subtotal facetectomy (OR 9.0, 95% CI 2.01–64.2; p = 0.009) and cervicothoracic versus other spinal region (OR 9.0, 95% CI 1.51–172.9; p = 0.048) were significantly associated with increased odds of performing immediate fusion. On multivariable analysis, only the effect of total facetectomy remained statistically significant (OR 6.75, 95% CI 1.47–48.8; p = 0.025).CONCLUSIONSThe authors found that total facetectomy and cervicothoracic involvement may be highly associated with the need for concomitant arthrodesis at the time of index surgery. These findings may help surgeons to determine the best surgical planning for patients with PNST.