Pathologic Peri-Implant Proximal Femur Fracture: Takeaways from Our Experience.

Pathologic fractures of the distal femur secondary to bone metastases are not as common as those in the proximal femur, and they are rarely reported on in the literature. Even in the absence of current metastatic lesions in the femoral neck, traditional orthopaedic teaching has stressed the importance of protecting the entire femur, while recent studies have shown that it may not be necessary to stabilize the entire femur in the event of future metastases. Thus, there is no consensus regarding optimal surgical treatment, making the choice of fixation often based on the experience of the surgeon. In this paper, we reported on a patient who presented with a pathologic fracture of the distal femur who was stabilized with a retrograde intramedullary nail and then subsequently suffered a pathologic fracture of the proximal femur. To our knowledge, there have been no cases reported on a peri-implant pathologic fracture proximal to a retrograde intramedullary nail in the setting of metastatic bone disease. We would like to share our experience on how to surgically manage this and discuss the literature around management of distal femoral bone metastases.

Adult-onset Langerhans cell histiocytosis of bone: A case series highlighting a rare entity.

Langerhans cell histiocytosis (LCH) is a neoplastic disorder derived from LCH precursor cells that can manifest as a single-system disease or a multisystem disorder. While extensively studied in children, LCH has received less attention in adult patients. We aimed to investigate the pathology and clinical course of LCH in adults presenting with a bone lesion. Cases of osseous LCH diagnosed in patients ≥18 in our center were analyzed. Histologic slides were reviewed, and clinical data were collated. Molecular analysis for BRAF mutation was performed in a subset. Twelve osseous LCH cases with classic morphology and CD1a+/S100+ immunophenotype were identified. Tumors occurred in six females and five males with a median age of 34 years (range: 18-77 years) and involved the craniofacial bones (4), pelvis (3), spine (2), appendicular skeleton (2), and rib (1). Radiographically, tumors appeared as ill-defined lytic lesions, often accompanied by cortical erosion and soft tissue extension, with pain being the most common presentation. On staging work-up with available data, two patients had multifocal bone lesions, two had multi-system disease, and four had solitary lesions. Two patients had prior or concurrent neoplasms, and 63 % of patients (5 out of 8) had a history of smoking. BRAF mutational analysis performed in six cases revealed a BRAFV600E mutation in one, negative result in one, and failed in four archived specimens. Our study highlights the importance of performing staging in patients with adult-onset LCH presenting as a bone lesion, as the clinical extent of the disease can vary widely among individuals.

Cooled Radiofrequency Ablation for Chronic Joint Pain Secondary to Hip and Shoulder Osteoarthritis.

Osteoarthritis (OA) of the shoulder and hip is a leading cause of physical disability and mental distress. Traditional nonsurgical management alone is often unable to completely address the associated chronic joint pain. Moreover, a large number of patients are not eligible for joint replacement surgery owing to comorbidities or cost. Radiofrequency ablation (RFA) of articular sensory nerve fibers can disrupt the transmission of nociceptive signals by neurolysis, thereby providing long-term pain relief. A subtype of RFA, cooled RFA (CRFA), utilizes internally cooled electrodes to generate larger ablative zones compared with standard RFA techniques. Given the complex variable innervation of large joints such as the glenohumeral and hip joints, a larger ablative treatment zone, such as that provided by CRFA, is desired to capture a greater number of afferent nociceptive fibers. The suprascapular, axillary, and lateral pectoral nerve articular sensory branches are targeted during CRFA of the glenohumeral joint. The obturator and femoral nerve articular sensory branches are targeted during CRFA of the hip. CRFA is a promising tool in the interventionalist's arsenal for management of OA-related pain and symptoms, particularly in patients who cannot undergo, have long wait times until, or have persistent pain following joint replacement surgery. An invited commentary by Tomasian is available online. ©RSNA, 2022.

Impact of Metastasectomy and Aggressive Local Therapy in Newly Diagnosed Metastatic Soft Tissue Sarcoma: An Analysis of the NCDB.

BACKGROUND: The optimal management of patients with stage IV soft tissue sarcoma of the extremity (STSE) with distant metastases at diagnosis is unclear due to limited evidence and heterogeneity of current practice patterns. National guidelines have recommended surgical management of the primary site (SP) with or without radiotherapy (R), chemotherapy (C), and metastasectomy (M). METHODS: In the National Cancer Database (NCDB), patients with initially metastatic STSE who received definitive SP from 2004 to 2014 were identified. Survival distributions were estimated and compared using the Kaplan-Meier method and log-rank tests, and covariates were compared using Chi-square tests or analysis of variance (ANOVA). Propensity score analysis using inverse probability of treatment weighting was used. RESULTS: Overall, 1124 patients were included, with a median age of 55 years (range 18-90). Utilization of SP+M increased over time from 18.8% in 2004-2006, to 33.3% in 2007-2009, to 47.9% in 2010-2014 (p = 0.024). The addition of M to SP was associated with superior 5-year overall survival (OS) at 30.8% (SP+M+/-C+/-R) compared with 18.2% for those treated with non-surgical adjuvant therapies (SP+/-C+/-R) and 12.6% for SP alone (p < 0.0001). Positive surgical margins were noted in 24.1% of patients and was associated with worse OS (hazard ratio 1.44, p < 0.001) on multivariable analysis. CONCLUSIONS: This is the first known study utilizing a large database to explore practice patterns and outcomes for patients with metastatic STSE receiving definitive SP. Utilization of metastasectomy increased in the study period and was associated with longer survival compared with SP alone. These hypothesis-generating data warrant additional study.

Alternative treatment of hip pain from advanced hip osteoarthritis utilizing cooled radiofrequency ablation: single institution pilot study.

OBJECTIVE: To establish the effectiveness of cooled radiofrequency ablation in managing hip pain from osteoarthritis at 6 months after receiving treatment in patients who failed conservative treatments and are not surgical candidates due to comorbidities or unwillingness to undergo arthroplasty surgery by targeting the femoral and obturator branches and assessing the degree of hip pain relief and change of function. MATERIALS AND METHODS: This prospective pilot study includes a total of 11 consecutive patients experiencing persistent chronic hip pain in the setting of advanced osteoarthritis. Patients initially underwent anesthetic blocks of the obturator and femoral nerve branches to determine cooled radiofrequency ablation candidacy. After adequate response to the anesthetic blocks (> 50% immediate pain relief), patients were subjected to the procedures 2-3 weeks later. Treatment response was evaluated utilizing clinically validated questionnaires and visual analog score in order to assess impact on pain severity, stiffness, and functional activities of daily living. Follow-up outcome scores were collected up to 6 months after cooled radiofrequency ablation procedure. RESULTS: A total of 11 hips were treated consecutively between August 2019 and March 2020 (mean patient age 61.4 years; 8 M:3F). The mean total HOOS score improved significantly from baseline at 17.0 ± 6.0 to 52.9 ± 5.4 at a mean of 6.2 months after treatment (p < 0.0001), with significant improvement in mean pain score from 16.1 ± 6.6 to 53.4 ± 7.4 (p < 0.0001) and mean stiffness score from 15.0 ± 8.1 to 53.6 ± 11.0 (p < 0.0001). No major complications were encountered. No patients went on to re-treatment, surgery, or other intervention. CONCLUSION: Image-guided obturator and femoral nerve cooled radiofrequency ablation is effective and safe in treating chronic hip pain/stiffness in the setting of advanced osteoarthritis.

A novel preoperative risk score to guide patient selection for resection of soft tissue sarcoma lung metastases: An analysis from the United States Sarcoma Collaborative.

BACKGROUND: Surgical resection for sarcoma lung metastases has been associated with improved overall survival (OS). METHODS: Patients who underwent curative-intent resection of sarcoma lung metastases (2000-2016) were identified from the US Sarcoma Collaborative. Patients with extrapulmonary metastatic disease or R2 resections of primary tumor or metastases were excluded. Primary endpoint was OS. RESULTS: Three hundred and fifty-two patients met inclusion criteria. Location of primary tumor was truncal/extremity in 85% (n = 270) and retroperitoneal in 15% (n = 49). Forty-nine percent (n = 171) of patients had solitary and 51% (n = 180) had multiple lung metastasis. Median OS was 49 months; 5-year OS 42%. Age ≥55 (HR 1.77), retroperitoneal primary (HR 1.67), R1 resection of primary (HR 1.72), and multiple (≥2) lung metastases (HR 1.77) were associated with decreased OS(all p < 0.05). Assigning one point for each factor, we developed a risk score from 0 to 4. Patients were then divided into two risk groups: low (0-1 factor) and high (2-4 factors). The low-risk group (n = 159) had significantly better 5-year OS compared to the high-risk group (n = 108) (51% vs. 16%, p < 0.001). CONCLUSION: We identified four characteristics that in aggregate portend a worse OS and created a novel prognostic risk score for patients with sarcoma lung metastases. Given that patients in the high-risk group have a projected OS of <20% at 5 years, this risk score, after external validation, will be an important tool to aid in preoperative counseling and consideration for multimodal therapy.

Safety and efficacy comparison of three- vs four-needle technique in the management of moderate to severe osteoarthritis of the knee using cooled radiofrequency ablation.

PURPOSE: To analyze the safety and efficacy of image-guided genicular nerve cooled radiofrequency ablation (C-RFA) for the treatment of pain in non-surgical candidates with moderate to severe knee osteoarthritis (OA) and to compare three- vs four-needle technique. METHOD: This retrospective study included 50 consecutive patients with pain from moderate to severe knee OA refractory to anti-inflammatory analgesia that failed multiple intra-articular lidocaine-steroid injections and who were non-surgical total knee arthroplasty candidates because of comorbidities. Patients initially underwent anesthetic blocks of the superior medial/lateral femoral and inferior medial tibial genicular nerve branches and in some cases the suprapatellar genicular nerve branch. Radiofrequency ablations of the same nerve branches were performed 1-2 weeks after the nerve blocks. Follow-up outcome was collected at approximately 2 weeks, 1, 3, and 6 months after the C-RFA procedure utilizing VAS and clinically validated questionnaires. RESULTS: A total of 77 knees were treated. The mean total KOOS score improved significantly from baseline at 24.7 ± 14.1 to 59.4 ± 26.5 at 6 months after treatment (p < 0.0001), with significant improvement in mean pain score from 25.5 ± 15.2 to 64.5 ± 25.2 (p < 0.0001) and mean stiffness score from 35.1 ± 21.9 to 65.8 ± 24.9 (p < 0.0001). At 6 months, 65% of all patients demonstrated decreased opiate medication usage, 79% of patients in the four-needle, and 45% of patients in the three-needle arms (p = 0.03). No complications were reported. CONCLUSIONS: The four-needle treatment approach offers an advantage in the overall efficacy in treating stiffness and pain in patients with moderate-to-severe OA refractory to conservative treatments leading to decreased opiate usage without complications.

A closer look at the natural history and recurrence patterns of high-grade truncal/extremity leiomyosarcomas: A multi-institutional analysis from the US Sarcoma Collaborative.

BACKGROUND/OBJECTIVE: Natural history and outcomes for truncal/extremity (TE) soft tissue sarcoma (STS) is derived primarily from studies investigating all histiotypes as one homogenous cohort. We aimed to define the recurrence rate (RR), recurrence patterns, and response to radiation of TE leiomyosarcomas (LMS). METHODS: Patients from the US Sarcoma Collaborative database with primary, high-grade TE STS were identified. Patients were grouped into LMS or other histology (non-LMS). Primary endpoints were locoregional recurrence-free survival (LR-RFS), distant-RFS (D-RFS), and disease specific survival (DSS). RESULTS: Of 1215 patients, 93 had LMS and 1122 non-LMS. In LMS patients, median age was 63 and median tumor size was 6 cm. In non-LMS patients, median age was 58 and median tumor size was 8 cm. In LMS patients, overall RR was 42% with 15% LR-RR and 29% D-RR. The 3yr LR-RFS, D-RFS, and DSS were 84%, 65%, and 76%, respectively. When considering high-risk (>5 cm and high-grade, n = 49) LMS patients, the overall RR was 45% with 12% LR-RR and 35% D-RR. 61% received radiation. The 3yr LR-RFS (78vs93%, p = 0.39), D-RFS (53vs63%, p = 0.27), and DSS (67vs91%, p = 0.17) were similar in those who did and did not receive radiation. High-risk, non-LMS patients had a similar overall RR of 42% with 15% LR-RR and 30% D-RR. 60% of non-LMS patients received radiation. There was an improved 3yr LR-RFS (82vs75%, p = 0.030) and DSS (77vs65%,p = 0.007) in non-LMS patients who received radiation. CONCLUSIONS: In our cohort, patients with LMS have a low local recurrence rate (12-15%) and modest distant recurrence rate (29-35%). However, LMS patients had no improvement in local control or long-term outcomes with radiation. The value of radiation in these patients merits further investigation.

Assessing the Role of Neoadjuvant Chemotherapy in Primary High-Risk Truncal/Extremity Soft Tissue Sarcomas: An Analysis of the Multi-institutional U.S. Sarcoma Collaborative.

BACKGROUND: The role of neoadjuvant chemotherapy (NCT) for high-risk soft tissue sarcoma (STS) is questioned. This study aimed to define which patients may experience a survival advantage with NCT. METHODS: All the patients from the U.S. Sarcoma Collaborative database (2000-2016) who underwent curative-intent resection of high-grade, primary truncal/extremity STS size 5 cm or larger were included in this study. The primary end points were recurrence-free survival (RFS) and overall survival (OS). RESULTS: Of the 4153 patients, 770 were included in the study. The median tumor size was 10 cm, and 669 of the patients (87%) had extremity tumors. The most common histology was undifferentiated pleomorphic sarcoma (UPS), found in 42% of the patients. Of the 770 patients, 216 (28%) received NCT. The patients who received NCT had deeper, larger tumors (p < 0.001). Of the patients with tumors 5 cm or larger and 8 cm or larger, NCT was not associated with improved RFS or OS. However for the patients with tumors 10 cm or larger, NCT was associated with improved 5-year RFS (51% vs 40%; p = 0.053) and 5-year OS (58% vs 47%; p = 0.043). By location, the patients with extremity tumors 10 cm or larger but not truncal tumors had improved 5-yearr RFS (54% vs 42%; p = 0.042) and 5-year OS (61% vs 47%; p = 0.015) with NCT. According to histology, no subtype had improved RFS or OS with NCT, although the patients with UPS had a trend toward improved 5-year RFS (56% vs 42%; p = 0.092) and 5-year OS (66% vs 52%; p = 0.103) with NCT. CONCLUSION: For the patients with high-grade STS, NCT was associated with improved RFS and OS when tumors were 10 cm or larger and located in the extremity. However, no histiotype-specific advantage was identified. Future studies assessing the efficacy of NCT may consider focusing on these patients, with added focus on histology-specific strategies.

Increase in PD-L1 expression after pre-operative radiotherapy for soft tissue sarcoma.

Soft tissue sarcomas (STS) have minimal expression of PD-L1, a biomarker for PD-1 therapy efficacy. Radiotherapy (RT) has been shown to increase PD-L1 expression pre-clinically. We examined the expression of PD-L1, pre- and post-RT, in 46 Stage II-III STS patients treated with pre-operative RT (50-50.4 Gy in 25-28 fractions) followed by resection. Five additional patients who did not receive RT were utilized as controls. PD-L1 expression on biopsy and resection samples was evaluated by immunochemistry using the anti PD-L1 monoclonal antibody (E1L3 N clone; Cell Signaling). Greater than 1% membranous staining was considered positive PD-L1 expression. Changes in PD-L1 expression were analyzed via the Fisher exact test. Kaplan-Meier statistics were used to correlate PD-L1 expression to distant metastases (DM) rate. The majority of STS were T2b (87.0%), high-grade (80.4%), undifferentiated pleomorphic histology (71.7%), and originated from the extremities (84.6%). Zero patients demonstrated PD-L1 tumor expression pre-RT. Post-RT, 5 patients (10.9%) demonstrated PD-L1 tumor expression (p = 0.056). Tumor associated macrophages (TAM) expression of PD-L1 increased after RT: 15.2% to 45.7% (p = 0.003). Samples from controls demonstrated no baseline (0%) or change in tumor PD-L1 expression. Freedom from DM was lower for patients with PD-L1 TAM expression post-RT (3 years: 49.7% vs. 87.8%, log-rank p = 0.006); TAM PD-L1 positivity remained an independent predictor for DM on multivariate analyses (Hazard ratio - 0.16, 95% confidence interval: 0.034-0.721, p = 0.042). PD-L1 expression on human STS tumor and TAM appears to elevate after pre-operative RT. Expression of PD-L1 on TAM after RT was associated with a higher rate of DM.

The Oncologic Impact of Postoperative Complications Following Resection of Truncal and Extremity Soft Tissue Sarcomas.

INTRODUCTION: Postoperative complications (POCs) negatively impact oncologic outcomes in some malignancies; however, little is known regarding their effect in soft tissue sarcoma (STS). The aim of this study was to determine the impact of POCs on survival after resection of truncal and extremity STS. METHODS: All patients who underwent resection for a primary truncal or extremity STS at a single academic institution from 2000 to 2015 were included and analyzed. Primary outcome was disease-specific survival (DSS). RESULTS: Among 546 STS patients, POCs occurred in 159 (29%) patients; 57% were major and 55% were surgical site infections. Patients with POCs were older (61 vs. 53 years), had more comorbidities (50 vs. 38%), longer operative time (127 vs. 93 min), higher-grade tumors (93 vs. 86%), and were more likely to receive preoperative radiation (42 vs. 33%; all p < 0.05). There was no difference in receipt of postoperative therapy between the POCs and no POCs groups (19 vs. 18%, p = 0.74). Median follow-up for survivors was 37 months, and the 5-year DSS for the entire cohort was 78%. Compared with patients without POCs, patients with POCs had a worse DSS (68% vs. 81%, p = 0.001). Predictors for decreased DSS on univariate analysis included POCs (hazard ratio [HR] 2.12, 95% confidence interval [CI] 1.37-3.28, p = 0.001), advanced age, neurovascular/bone resection, positive margin, high grade, and preoperative and postoperative therapy (all p < 0.05). POCs (HR 1.76, 95% CI 1.08-2.87, p = 0.02) remained an independent predictor for reduced DSS on multivariate analysis, along with age (HR 1.02, p = 0.046) and tumor grade (HR 7.62, p = 0.046). CONCLUSIONS: POCs following resection of truncal and extremity STS are associated with decreased DSS. Efforts to optimize modifiable risk factors and decrease the rate of POCs warrant further investigation.

Cryoablation of Osteoid Osteoma in the Pediatric and Adolescent Population.

PURPOSE: To evaluate the technical feasibility and clinical efficacy of osteoid osteoma (OO) cryoablation in a large, pediatric/adolescent cohort. MATERIALS AND METHODS: An electronic medical record and imaging archive review was performed to identify all cryoablations performed for OOs between 2011 and 2015 at a single tertiary care pediatric hospital. The subsequent analysis included 29 patients with suspected OOs treated by cryoablation (age range, 3-18 y; mean age, 11.3 y; 17 boys; 12 girls). Conventional CT guidance was used in 22 procedures; cone-beam CT guidance was used in 7 procedures. Follow-up data were obtained via a standardized telephone questionnaire (23/29 patients; 79.3%) and clinical notes (5/29 patients; 17.2%). One patient was lost to follow-up. RESULTS: Technical success was achieved in 100% of patients (29/29). Immediate clinical success (cessation of pain and nonsteroidal antiinflammatory drug [NSAID] use within 1 mo after the procedure) was achieved in 27/28 patients (96.4%). Short-term clinical success (cessation of pain and NSAID use for > 3 mo after the procedure) was achieved in 24/25 patients (96%). Long-term clinical success (cessation of pain and NSAID use for > 12 mo after the procedure) was achieved in 19/21 patients (90.5%). Median pain scale score before the procedure was 10 (range, 5-10); median pain scale score after the procedure was 0 (range, 0-8; P < .0001). There were 6 minor complications (21%) and no major complications. CONCLUSION: Image-guided cryoablation is a technically feasible, clinically efficacious therapeutic option for children and adolescents with symptomatic OO.

PET Imaging in Sarcoma.

PET imaging has been evaluated in five areas of sarcoma diagnosis and treatment: biopsy guidance, therapeutic monitoring, tumor detection and grading, tumor staging, and prognostication. Current evidence does not include any cost-benefit analysis showing a decreased number of invasive procedures from false-positive results. There is overlap from more conventional imaging and PET imaging without obvious added benefit from information gained from PET/computed tomography scanning. Use as a routine test in patients with sarcoma cannot be recommended. Use in specific histologic subtypes with differing patterns of metastasis or in monitoring those cases undergoing neoadjuvant chemotherapy needs further study before PET/computed tomography becomes standard of care for patients with sarcoma.

The General Surgeon's quandary: atypical lipomatous tumor vs lipoma, who needs a surgical oncologist?

BACKGROUND: Differentiating large lipomas from atypical lipomatous tumors (ALT) is challenging, and preoperative management guidelines are not well defined. The diagnostic ambiguity leads many surgeons to refer all patients with large lipomatous masses to an oncologic specialist, perhaps unnecessarily. STUDY DESIGN: In this retrospective cohort study of patients with nonretroperitoneal lipomatous tumors, preoperative characteristics discernible without invasive diagnostic procedures were evaluated for diagnostic predictive value. RESULTS: We identified 319 patients (256 with lipomas, 63 with ALTs) treated between 1994 and 2012. Patients with ALTs were older (60.5 vs 53.5 years, p < 0.0001), had larger tumors (16.0 vs 8.3 cm, p < 0.0001), had tumors more often located on an extremity (88.9% vs 60.5% torso, p < 0.0001), and more frequently had a history of previous operations at the same site, exclusive of excision leading to diagnosis and referral (20.6% vs 5.9%, p = 0.001). Local recurrence was observed in 2 patients with lipomas (0.8%) vs 14 with ALTs (22.6%, p < 0.0001). No patients with ALTs developed distant metastases or disease-specific mortality, with a median follow-up of 27.4 months (range 0 to 164.6 months). On multivariate analysis, age ≥ 55 years, tumor size ≥ 10 cm, extremity location, and history of previous resections were predictors for diagnosis of ALT (p < 0.05). CONCLUSIONS: Characteristics of lipomatous masses associated with a diagnosis of ALT include patient age ≥ 55 years, tumor size ≥ 10 cm, previous resection, and extremity location (vs torso). These easily identifiable traits may guide surgical management or referral to a specialist.

Ewing sarcoma with 7;22 translocation: three new cases and clinicopathological characterization.

Ewing sarcoma (ES) is the second most common primary bone malignancy in children and is typically characterized by a translocation involving the EWS gene on chromosome 22 and a member of the ETS family of genes: FLI1 (90%), ERG1 (5%), ETV1 (1%), ETV4 (1%), and FEV (1%). We identified three new cases of t(7;22) (p22;q12) (EWS-ETV1) ES and a literature search revealed an additional six cases. In comparison to conventional ES with t(11;22) (q24;q12) (EWS-FLI1), the t(7;22) ES variant has a higher propensity for females and children in a younger age group and it occurs more commonly in extraosseous locations.

Unusual presentation of metastatic Ewing sarcoma to the ovary in a 13 year-old: a case report and review.

Ewing sarcoma (ES) is the second most common bone malignancy in children and adolescents. Together with primitive neuroectodermal tumors (PNET), ES comprises the PNET/ES family. Metastasis is present in about 25% of patients at diagnosis and is most commonly found in the lung and bones. Primary PNET/ES of the ovary has been reported in many adult cases; however, secondary occurrences are rare. Here we present the clinical course of a 13-year-old patient with metastatic ES to the ovary without involvement of any other sites. To our knowledge, this is the second reported pediatric case of metastatic ES to the ovary.

Anatomic tumor location influences the success of contemporary limb-sparing surgery and radiation among adults with soft tissue sarcomas of the extremities.

PURPOSE: To examine the influence of anatomic location in the upper extremity (UE) vs. lower extremity (LE) on the presentation and outcomes of adult soft tissue sarcomas (STS). METHODS AND MATERIALS: From 2001 to 2008, 118 patients underwent limb-sparing surgery (LSS) and external beam radiotherapy (RT) with curative intent for nonrecurrent extremity STS. RT was delivered preoperatively in 96 and postoperatively in 22 patients. Lesions arose in the UE in 28 and in the LE in 90 patients. Patients with UE lesions had smaller tumors (4.5 vs. 9.0 cm, p < 0.01), were more likely to undergo a prior excision (43 vs. 22%, p = 0.03), to have close or positive margins after resection (71 vs. 49%, p = 0.04), and to undergo postoperative RT (32 vs. 14%, p = 0.04). RESULTS: Five-year actuarial local recurrence-free and distant metastasis-free survival rates for the entire group were 85 and 74%, with no difference observed between the UE and LE cohorts. Five-year actuarial probability of wound reoperation rates were 4 vs. 29% (p < 0.01) in the UE and LE respectively. Thigh lesions accounted for 84% of the required wound reoperations. The distribution of tumors within the anterior, medial, and posterior thigh compartments was 51%, 26%, and 23%. Subset analysis by compartment showed no difference in the probability of wound reoperation between the anterior and medial/posterior compartments (29 vs. 30%, p = 0.68). Neurolysis was performed during resection in (15%, 5%, and 67%, p < 0.01) of tumors in the anterior, medial, and posterior compartments. CONCLUSIONS: Tumors in the UE and LE differ significantly with respect to size and management details. The anatomy of the UE poses technical impediments to an R0 resection. Thigh tumors are associated with higher wound reoperation rates. Tumor resection in the posterior thigh compartment is more likely to result in nerve injury. A better understanding of the inherent differences between tumors in various extremity sites will assist in individualizing treatment.

Fibrocartilaginous mesenchymoma, a unique osseous lesion: case report with review of the literature.

Fibrocartilaginous mesenchymoma is a rare osseous tumor that primarily arises in the long bones of children and adolescents. This lesion can grow quickly and reach a considerable size, despite its benign nature. It has proved challenging to diagnose and can be mistaken for a spectrum of benign and malignant bone tumors. The histological presentation of unique epiphyseal plate-like cartilage with destruction of the surrounding cortical bone and exhibition of dense fibrous stroma are important indicators for the diagnosis of fibrocartilaginous mesenchymoma. An 11-year-old boy presented with a left proximal humerus mass thought to be an aneurysmal bone cyst. The patient was lost to follow-up and came back 3 years later with massive growth of the lesion. Owing to the aggressive nature of the tumor, a left forequarter amputation was performed. Histological examination demonstrated numerous islands of cartilage with an exuberant spindle cell component characteristic of FCM. No distant metastases or local recurrences were identified at 2 years post-amputation. Because of the rapid growth of this lesion, it should be considered in the differential diagnosis of bone lesions in children and young adults.