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Introduction: conventional parosteal osteosarcoma is an uncommon malignant bone tumor, comprising 4% of all osteosarcomas. Although rare, parosteal osteosarcoma is the most common type of osteosarcoma of the bone surface. We present the clinical, histological and imaging characteristics of a rare histologic variant of a parosteal osteosarcoma, review the literature and emphasize the importance of radio-pathological correlation as well as the interpretation of a representative biopsy in order to obtain the correct diagnosis., Case Report: a 36-year old woman began her condition one year prior to admission to the hospital with increased volume in the left knee and pain. Image studies showed a juxtacortical heterogeneous tumor localized on the posterior surface of the distal femoral metaphysis. An incisional biopsy was performed, with the diagnosis of a Parosteal Osteosarcoma and a wide surgical resection was undertaken. According to the findings of the surgical specimen, the diagnosis of a Parosteal Osteosarcoma with low grade chondrosarcoma and liposarcoma components was made. The knowledge of this rare parosteal osteosarcoma variant can lead the orthopedic oncologists to avoid overlooking the adipose component and provide adequate surgical margins., Conclusion: we present the clinical, histological and imaging characteristics of a Parosteal Osteosarcoma with low grade liposarcoma and chondrosarcoma components.

Background: Challenging emerging entities with distinctive molecular signatures may benefit from algorithms for diagnostic work-up., Methods: Fusion sarcomas (2020-2021, during pandemic) were diagnosed by clinicoradiology, morphology, phenotype, and next-generation sequencing (NGS)., Results: Six fusion sarcomas in two males and four females involved the chest-wall, neck, or extremities; ages ranged 2-73, median 18 years. Sizes ranged 5.3-25.0, median 9.1 cm. These include high grade 1) TPR-NTRK1 of proximal femur with a larger rounded soft tissue mass, previously considered osteosarcoma yet without convincing tumor matrix. A pathologic fracture necessitated emergency hemipelvectomy (NED) and 2) novel KANK1-NTRK2 sarcoma of bone and soft tissue with spindled pleomorphic to epithelioid features (AWD metastases). 3) Novel ERC1-ALK unaligned fusion, a low grade infiltrative deep soft tissue hand sarcoma with prominent-vascularity, myopericytoid/lipofibromatosis-like ovoid cells, and collagenized stroma, was successfully treated with ALK-inhibitor (Crizotinib), avoiding amputation. These NTRK and ALK tumors variably express S100 and CD34 and were negative for SOX10. 4) and 5) CIC-DUX4 round cell tumors (rapid metastases/demise), one with COVID superinfection, were previously treated as Ewing sarcoma. These demonstrated mild pleomorphism and necrosis, variable myxoid change and CD99 reactivity, and a distinctive dot-like-Golgi WT1 immunostaining pattern. 6) A chest wall/thoracic round cell sarcoma, focal CD34/ keratins/CK7, revealed nuclear-STAT6, STAT6-NAB2 by NGS, confirming malignant solitary fibrous tumor, intermediate-risk-stratification (AWD metastases)., Conclusions: Recent fusion sarcomas include new KANK1-NTRK2 and ERC1-ALK, the latter successfully treated by targeted-therapy. ALK/NTRK fusion partners TPR and KANK1 suggest unusual high-grade morphology/behavior. Clinicoradiologic, morphologic, and phenotypic algorithms can prompt molecular-targeted immunostains or NGS for final classification and promising inhibitor therapy., (Copyright © 2021. Published by Elsevier Inc.)

Introduction: Rhabdomyosarcoma (RMS) is a malignant solid tumor of mesenchymal origin. It is the most com mon soft-tissue sarcoma in childhood and adolescence. 65% of cases are diagnosed before the age of 6. Histological subtypes include embryonal, alveolar, pleomorphic, and fused-cell RMS. The embryo nal subtype is more frequent in children, while the alveolar one is more frequent in adolescents and adults., Objective: To describe the clinical presentation of primary alveolar rhabdomyosarcoma in a schoolgirl., Clinical Case: 7-year-old schoolgirl with one-month history of progressive pain in her left thigh. X-ray shows a lytic lesion in the left femur diaphysis. A study was performed with 2 biopsies, immunohistochemistry, and PAX-FOXO1 studies which were compatible with alveolar RMS. Con clusion: Primary alveolar rhabdomyosarcoma of the bone is rare, but it should be considered within the differential diagnosis of primary small-round-blue cell bone tumors. Despite presenting a poor prognosis cytogenetic, this type of tumor seems to have better biological behavior, which for a successful treatment makes necessary to have a high index of suspicion in order to install a multimodal therapy in the context of a national protocol.

Rationale: Osteosarcoma is the most common primary malignant bone tumor in children. The prognosis of osteosarcoma has improved with the use of aggressive systemic chemotherapy in addition to surgery. The relapse of osteosarcomas is usually as lung metastasis observed within 2 to 3 years after the initial treatment. A relapse is rarely observed at >10 years., Patient Concerns: We report the case of a 51-year-old Japanese man who was treated for high-grade osteosarcoma of the femur at 13 years old. He was referred to our hospital with a suspicion of primary lung cancer based on back pain, respiratory distress, and an abnormal mass on chest radiograph., Diagnoses: Computed tomography-guided biopsy confirmed the lung lesion as a metastatic recurrence of high-grade osteosarcoma without local recurrence., Interventions: Chemotherapy was planned, but the patient's general condition rapidly deteriorated and thus palliative therapy was provided., Outcomes: The patient died 2 months after the initial consultation., Lessons: The survival durations of osteosarcoma patients have been prolonged by recent progress in multimodality therapy, and thus clinicians as well as osteosarcoma patients should always keep in mind the possibility of very late relapse.

Osteosarcoma arising from cortical surface is classified into parosteal, periosteal and high-grade surface osteosarcoma. Along the spectrum, parosteal osteosarcoma occupies the well-differentiated end. It is a relatively rare disease entity, comprised only 4% of all osteosarcomas and barely reported in the literature. The objective of this study is to describe cases of parosteal osteosarcoma as well as a variety of treatment options amenable to such entity. Six cases of parosteal osteosarcoma were identified based on histopathological reports in a tertiary referral hospital in Jakarta, Indonesia between January 2001 and December 2019. The mean age was 29.8 years old; four of them (66.7%) were male. Distal end of femur was the most commonly involved bone (five cases, 83.3%). The patients were treated with wide excision followed by several different reconstruction methods: replacement with endoprosthesis, extracorporeal irradiation, knee arthrodesis, or prophylactic fixation. One of our patients presented with dedifferentiated component, and therefore was treated by limb ablation. While two cases died of pulmonary metastasis, other patients reported fair to excellent functional outcome., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2020 Yogi Prabowo et al.)

An 11-year-old female was referred to physical therapy due to a 3-month history of right medial knee pain. The patient's medical diagnosis was Osgood-Schlatter disease, based on radiographs obtained at the initial pediatrician consultation. An MRI scan was obtained 2 weeks after starting physical therapy and revealed a bony lesion near the medial condyle of the right femur and damage to medial joint structures. Pathology after open biopsy and curettage of the lesion revealed a chondroblastoma. J Orthop Sports Phys Ther 2020;50(5):275. doi:10.2519/jospt.2020.9021 .

Introduction: The capacity of the hydroxyapatite-coated trochanteric screwed plates used with modular hip implants to restore abductor system efficacy after proximal femoral tumor resection has never been assessed. We therefore conducted a retrospective study aiming to: (1) quantitatively evaluate abduction conservation on dynamometry according to use of digastric reinsertion, conserving continuity between the gluteus medius and vastus lateralis muscles, or not, and of standard versus small-offset; (2) assess radiographic trochanteric plate fixation; (3) assess functional scores; and (4) assess complications., Hypothesis: Trochanteric reinsertion better conserves abduction strength when reinsertion is digastric., Patients and Methods: Thirty-one patients undergoing proximal femoral tumor resection between 2006 and 2016 with reconstruction by Stanmore METS™ modular implant with trochanteric plate were included. Twenty-one had digastric fixation between the gluteus medius and vastus lateralis and 10 had simple trochanteric fixation without digastric continuity. Abduction strength was compared between sides on dynamometer. Sixteen patients had full assessment of muscle strength, by a single observer; there were 8 deaths, 5 patients lost to follow-up, and 2 cases of material removal., Results: Abduction strength conservation versus the contralateral side was 55.2±23.3% (range, 5.8-86.1%): 66.6±13.0% (46.4-86.1) with versus 36.0±24.7% (5.8-63.2%) without digastric continuity (p=0.01); severe limp rate was 4/21 when digastric continuity was preserved (19%) versus 6/10 (60%) (p=0.04), and radiologic trochanteric reinsertion stability rate was 19/21 (90%) versus 4/10 (40%) (p=0.005). Standard femoral offset conserved greater abduction strength: 64.9±20.0% versus small-offset 45.4±23.2% (p=0.05). Toronto Extremity Salvage Score (TESS) was 89±9.4%, and Musculoskeletal Tumor Society (MSTS) score 75.4±5.4%. There were 6 complications (19%): 4 infections, 1 dislocation, and 1 plate removal; the single dislocation (3%) was in the digastric conservation group. TESS (90.7±7.8% vs 88.3±4) and MSTS score (75.6±4.0% vs 75.1±3.7) and complications [4/21 (19%) vs 2/10 (20%)] did not differ according to digastric or non-digastric reinsertion (p=1)., Conclusions: Abduction strength with a modular implant using a hydroxyapatite-coated trochanteric plate was better conserved by digastric trochanteric reinsertion, resulting in less limping, although the complications rate and functional scores were unaffected. Longer term assessment is needed to confirm this conservation of abduction strength., Level of Evidence: IV, retrospective study without control group., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)

Aim: The aim of this study was to assess outcomes of biological (nonvascularized fibula grafts and extracorporeal irradiated autologous bone grafts) methods used for reconstruction of intercalary defects after resection of femoral diaphyseal tumors., Materials and Methods: This study included 28 patients who had undergone intercalary resection in femoral diaphyseal tumors between 2011 and 2016. The mean follow-up period was 24 months (range 12-57 months)., Results: The mean union time for diaphyseo-diaphyseal union was 10.5 and 11 months in nonvascularized fibula group and extracorporeal radiotherapy (ECRT) group, respectively. The mean union time for metaphyseo-diaphyseal union was 6.5 months in both nonvascularized fibula and ECRT groups. Six patients had distant metastasis, and one patient had local recurrence. The mean Musculoskeletal Tumor Society score was 28 at the last follow-up. Two patients had surgical site infection in the nonvascularized fibula group. Implant failure was found in one patient of the ECRT group requiring revision surgery. Three patients had nonunion (two from the nonvascularized fibula group and one from the ECRT group)., Conclusion: The present study indicates that the biological reconstruction modalities provide good functional outcomes in diaphyseal tumors of femur. Nonvasularized fibula and ECRT-treated autografts reconstruction provides good results, and union timing is comparable. The outcomes of the current study are promising as compared to the results in the reviewed literature. The reconstruction method depends on the resources available at the oncological center and the conversance with the method of the treating surgeon.

We report a rare case of giant periosteal osteoblastoma in the femur of a 21-year-old male. The patient presented with a painful, firm, non-tender mass in his left thigh. The pain was worse at night and was temporarily relieved with NSAIDS. He had no fevers, night sweats, or weight loss. The patient underwent preoperative radiological studies including plain radiographs, MRI, bone scan, and CT scan. An open biopsy was subsequently performed that was consistent with an aggressive, epithelioid osteoblastoma. Pathology demonstrated a neoplasm characterized by cohesive sheets of epithelioid osteoblasts, mixed with areas of conventional osteoblastoma displaying prominent osteoblastic rimming of woven bone trabeculae in a fibrovascular stroma. The patient subsequently underwent resection, cryosurgery, fixation, and bone grafting with cortical strut allografts. At final follow-up, 32 months postoperatively, there was no evidence of local recurrence. The patient had resumed all his normal activities. He could run without pain and had no restrictions with activities. The goal of this case report is to aid professionals in the diagnosis and treatment of highly uncommon aggressive osteoblastomas.

Background: The proximal femuris is an uncommon site of osteosarcoma. The unusual manifestations at this site may lead to diagnostic and therapeutic mistakes. We therefore performed a retrospective study to estimate the proportions of patients with imaging study findings and/or clinical manifestations typical for osteosarcoma and/or inappropriate treatment decisions., Hypothesis: Proximal femoral osteosarcoma often produces atypical clinical and radiological presentations., Material and Methods: Consecutive patients who underwent surgery at our center to treat proximal femoral osteosarcoma were included. For each patient, we collected the epidemiological characteristics, clinical symptoms, imaging study findings, treatment, and tumor outcome. Proportions were computed with their confidence intervals., Results: Twelve patients had surgery for proximal femoral osteosarcoma between 1986 and 2015. Imaging findings were typical in 1 (8%) patient; they consisted of ill-defined osteolysis in 11/12 (92%) patients, a periosteal reaction in 1/12 (8%) patient, soft tissue involvement in 7/12 (58%) patients, and immature osteoid matrix in 11/12 (92%) patients. No patient had the typical combination of pain with a soft tissue swelling. Management was inappropriate in 2/12 (17%) patients, who did not undergo all the recommended imaging studies before surgery and were treated in another center before the correct diagnosis was established. At last follow-up, 4 patients had died (after a mean of 7 years) and 8 were alive (after a mean of 4 years)., Conclusion: Proximal femoral osteosarcoma is uncommon and rarely produces the typical clinical and imaging study findings. The atypical presentation often results in diagnostic errors and inappropriate treatments. Ill-defined osteolysis on standard radiographs should prompt computed tomography or magnetic resonance imaging of the proximal femur. Treatment in a specialized center is imperative., Level of Evidence: IV, retrospective study., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

This article describes a 71-year-old man with right knee pain, prerenal azotemia, hypercalcemia, and a mass in the distal femur. Although testing, including bone marrow biopsy, initially ruled out myeloma, an open surgical biopsy eventually confirmed the diagnosis as lymphoma involving the bone with classic histologic findings of mature B-cell neoplasm of germinal cell origin.

Background: The aim of this study was to compare the functional outcomes and complication rates after distal femoral replacement (DFR) performed with the modular Munich-Luebeck (MML) modular prosthesis (ESKA/Orthodynamics, Luebeck, Germany) in patients being treated for malignant disease or failed total knee arthroplasty., Methods: A retrospective review of patient charts and a functional investigation (involving Musculoskeletal Tumor Society Score [MSTS], American Knee Society Score [AKSS], Oxford Knee Score [OKS], Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], Toronto Extremity Salvage Score [TESS], the 12-Item Short-Form [SF-12] Health Survey, and a failure classification system developed by Henderson et al.) of DFR cases from 2002 to 2015 were conducted. The indications for DFR were malignant tumor resection in the femur (n = 20, group A) or failure of revision total knee arthroplasty without a history of malignant disease (n = 16, group B)., Results: One-hundred and twenty-nine patients were treated during the study period. Of these, 82 were analyzed for complications and implant-survival. Further, 36 patients were available for functional assessment after a mean follow-up of 86 months (range: 24-154). There were 75 complications in total. The overall failure rate for DFR was 64.6% (53/82 patients). The most common failure mechanisms were type III (mechanical failure), followed by type I (soft tissue) and type II (aseptic loosening). The mean MSTS score (out of 30) was 17 for group A and 12 for group B. All the clinical outcome scores revealed an age-dependent deterioration of function., Conclusion: DFR is an established procedure to restore distal femoral integrity. However, complication rates are high. Post-procedure functionality depends mainly on the patient's age at initial reconstruction.

Arterial pseudoaneurysms associated with osteochondromas are rare and most publications on this topic are case reports. The management of this double entity is not standardized. We wanted to update it. Literature searches on MEDLINE and EMBASE were performed using the keywords "artery pseudoaneurysm" and "osteochondroma". Patient demographics, clinical presentations, diagnostic and therapeutic modalities were reviewed. In sum, 101 cases were analyzed. Overall, young adults represented the majority of the affected population with a masculine preponderancy (86%). Painful swelling (51%) was the most commonly physical finding. Distal femur was the most common site of the osteochondroma (86%). Multiple hereditary exostosis was seldom reported (36%). Diagnostic confirmation was dominated by arteriography (55%). Popliteal artery (77%) was the most commonly injured vessel. The treatment was open surgery with vascular repair and optimal exostectomy. Arterial repair was performed with saphenous vein grafting (40%) or lateral suture (39%). Postoperative courses were often uneventful (97%). Arterial pseudoaneurysms resulted from osteochondromas were dominated by those involving the popliteal artery. The use of arteriography to confirm the diagnosis may be limited to the benefit of non-invasive radiological methods because endovascular treatment is not relevant in the setting of osteochondroma-induced arterial pseudoaneurysm., (© The Author(s) 2016.)

Background: The aim of this retrospective study was to investigate the frequency of intra-articular osteoid osteoma (iaOO) in a large study cohort and to demonstrate its clinical relevance as an important differential diagnosis of non-specific mono-articular joint pain., Methods: We searched the registry for bone tumours of the University Medical Centre Hamburg-Eppendorf for osteoid osteomas in the last 42 years. Herein, we present three selected iaOO which were detected in the three major weight-bearing joints. Computed tomography (CT) or magnetic resonance imaging (MRI) scans were performed for initial diagnosis., Results: Out of a total of 367 osteoid osteomas, 19 (5.2 %) tumours were localized intra-articularly. In all three presented tumours, a history of severe mono-articular pain was reported; however, the mean time to correct diagnosis was delayed to 20.7 months. Clearly, the nidus seen in CT and MRI images in combination with inconsistent salicylate-responsive nocturnal pain led to the diagnosis of iaOO., Conclusions: Rarely, osteoid osteoma can occur in an intra-articular location. In cases of diffuse mono-articular pain, iaOO should be considered both in large and smaller joints to avoid delays in diagnosis and therapy of this benign bone tumour.

Giant cell tumor of bone (GCT) is a benign neoplasm that most commonly presents with pain and is rarely diagnosed as an incidental finding. We present the report of a young woman whose pre-operative MRI was only noted to have a tear of the anterior cruciate ligament (ACL). Subsequently, the patient underwent anACL reconstruction. A second MRI, performed four years later, demonstrated an enlarged mass in the same location. A retrospective evaluation of the initial MRI revealed an eccentric metaphyseal lesion. Histology obtained from the lesion demonstrated a giant cell tumor of bone. We present the case of an asymptomatic GCT discovered retrospectively as an incidental finding and reevaluated four years later. 'Ihis case serves as a reminder of the importance for the critical review of routine preoperative imaging and also offers a unique perspective on the natural history of giant cell tumor of bone.

Review current treatments of metastatic lesions in the proximal femur.We reviewed published literature related to diagnosis and surgical treatments and summarized current treatment options.Surgical management mainly consist of internal fixation, hip replacement, and percutaneous femoroplasty (PFP) which has been newly applied in clinical practice.An appropriate series of treatments is necessary for patients to avoid the occurrence of paraplegia and prolong survival time.

Background: Adamantinoma arising in the femur is extremely rare. We report a case of an adamantinoma occurring in the right medial femoral condyle that was diagnosed 5 years after the primary surgery., Case Presentation: A 74-year-old Asian woman first complained of right knee pain without any cause. Radiographs demonstrated a 4×4.5 cm osteolytic lesion in her medial femoral condyle. Magnetic resonance imaging revealed a lesion which showed low signal on both T1 and T2-weighted image, and enhanced signal with gadolinium contrast administration. She underwent a wide resection of the lesion and was reconstructed with a tumor endoprosthesis. On histological examination, the tumor showed clusters of spindle-shaped and squamoid epithelial cells among the fibrous stroma. Adamantinoma was considered, however, the diagnosis was inconclusive due to the unusual localization and her age. Moreover, it was difficult to exclude metastatic carcinoma. Five years later, she was diagnosed with an abnormal shadow occupying the upper lobe of her right lung in a routine physical examination. She subsequently underwent a resection of the lung mass which histologically showed proliferation of spindle-shaped and squamoid epithelial cells. The histological similarity of the lung tumor and the femoral tumor led to the diagnosis of adamantinoma arising in her right medial femoral condyle with metastasis to the upper lobe of her right lung., Conclusion: In this case report, we report the clinical, radiographic, and histological features of an adamantinoma arising in the distal femur with a review of the literature.

Carcinoembryonic antigen related cell adhesion molecule 1 (CEACAM1) is a trans-membrane multifunctional cell adhesion molecule associated with tumor cell proliferation, apoptosis, angiogenesis, invasion, and migration during tumor development. In the present study, we evaluated serum CEACAM1 level in osteosarcoma patients to explore its diagnostic and prognostic value for this particular malignancy. Sera from 113 patients with primary osteosarcoma, 98 patients with benign bone tumors and 126 healthy controls were obtained. Serum CEACAM1 level was measured with ELISA and correlation with clinicopathological characteristics was further analyzed. Receiver operating curves (ROC), Kaplan-Meier curves, and log-rank analyses as well as Cox proportional hazard models were used to evaluate diagnostic and prognostic significance. The results revealed that serum CEACAM1 level was significantly higher in osteosarcoma patients compared to benign bone tumors and healthy controls (455.2 ± 179.9 vs 287.4 ± 103.2, 260.8 ± 109.7 pg/ml, respectively). Osteosarcoma patients with larger tumors, later-tumor stages, low tumor grades, and distant metastases had much higher CEACAM1 compared to those with smaller tumors, earlier tumor stages, high tumor grades and non-distant metastases (P < 0.05 for all). Multivariate logistic regression analysis confirmed that high serum CEACAM1 level was an independent risk factor for distant metastases (OR = 3.02, 95%CI 1.65-4.17). To distinguish osteosarcoma patients from those with benign bone tumor and healthy controls, ROC/AUC analysis indicated an AUC of 0.81 (sensitivity 0.61; specificity 0.89) and an AUC of 0.77 (sensitivity 0.57; specificity 0.92), respectively. Osteosarcoma patients with higher CEACAM1 had relatively lower survival compared to those with low CEACAM1 (P < 0.01), and multivariate analyses for overall survival revealed that high serum CEACAM1 level was an independent prognostic factor for osteosarcoma (HR = 1.56, 95%CI 1.23-3.28). The present study suggested that elevated serum CEACAM1 level might be a novel diagnostic and prognostic biomarker for osteosarcoma patients.

Tumour-induced osteomalacia (TIO) is a rare paraneoplastic syndrome characterised by severe hypophosphataemia and osteomalacia, with renal phosphate wasting that occurs in association with tumour. The epidemiology likewise aetiology is not known. The clinical presentation of TIO includes bone fractures, bone and muscular pains, and sometimes height and weight loss. TIO may be associated with mesenchymal tumours which may be benign or malignant in rare cases. Mesenchymal tumour itself may be related to fibroblast growth factor 23 (FGF23), which is responsible for hypophosphataemia and phosphaturia occurring in this paraneoplastic syndrome. Hypophosphataemia, phosphaturia and elevated alkaline phosphatase are the main laboratory readings that may lead to more precise investigations and better diagnosis. Finding the tumour can be a major diagnostic challenge and may involve total body magnetic resonance imaging, computed tomography and scintigraphy using radiolabelled somatostatin analogue. The treatment of choice for TIO is resection of a tumour with a wide margin to insure complete tumour removal, as recurrences of these tumours have been reported. We provide here an overview on the current available TIO case reports and review the best practices that may lead to earlier recognition of TIO and the subsequent treatment thereof, even though biochemical background and the long-term prognosis of the disease are not well understood. This review also includes a 4-year-long history of a patient that featured muscular pains, weakness and multiple stress fractures localised in the hips and vertebra with subsequent recovery after tumour resection. Because the occurrence of such a condition is rare, it may take years to correctly diagnose the disease, as is reported in this case report.

Malignant transformation of fibrous dysplasia (FD) in long bones is rare (less than 1% of cases) and occurs in the form of osteosarcomas. They can occur on FD associated with multiple myxomas, which corresponds to Mazabraud syndrome. To our knowledge, only six cases of FD malignant transformation into osteosarcoma in the context of Mazabraud syndrome have been described. Here, we describe the first case of malignant transformation of femur FD into chondrosarcoma in a 51-year-old female patient. The patient had significant changes in the size and number of myxomas around the femur before the malignant transformation into chondrosarcoma. She underwent complete femur replacement with a favourable result after 4 years' follow-up. Close surveillance is strongly recommended in this syndrome, particularly when the number and size of myxomas increase., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)

Objective: Osteoid osteoma is a benign bone tumor that is commonly located in the proximal femur. Although CT is helpful in the diagnosis of osteoid osteoma, patients in whom the clinical presentation of the tumor is atypical are first referred to undergo MRI, which yields a high percentage of false-negative or inconclusive results. We sought to explore the association between a half-moon sign of bone marrow edema and the presence of osteoid osteoma of the femoral neck., Subjects and Methods: The MRI examinations of 11 consecutive patients with osteoid osteoma (group 1) were prospectively included in the study. In addition, 950 consecutive hip MRI examinations of 485 patients were retrospectively analyzed for the presence of bone marrow edema of the femoral neck, with 19 patients identified as having bone marrow edema resulting from causes other than osteoid osteoma (group 2). Patients in both study groups were evaluated for the presence of the half-moon sign., Results: The half-moon sign of bone marrow edema was significantly associated with the presence of osteoid osteoma (p < 0.0001), having been seen on the MR images of all 11 patients in group 1 and only one of 19 patients in group 2. MRI examination was therefore 94.7% specific and 100% sensitive for the detection of osteoid osteoma, with positive and negative predictive values of 91.7% and 100%, respectively., Conclusion: The half-moon sign is an MRI finding that is highly specific and sensitive for an accurate diagnosis of osteoid osteoma of the femoral neck.

A rare case is presented of a 62-year-old man with primary isolated cryptococcal femoral osteomyelitis. Magnetic resonance imaging (MRI) revealed osteolytic destruction of his left femur. Biopsy was performed firstly. Under microscope, the lesion was compose of numerous large mononuclear cells, scattered multinucleated giant cells, a few lymphocytes and neutrophils, necrosis with serious artificial deformation. By immunohistochemistry (IHC), only CD31 and CD68 were positive, while CK, CK8/18, EMA, P63, CK7, CK20, PSAP, PSA, CD34 negative. It was considered a low grade vascularsarcoma, but not confirmed. Then the operation was done. Surgical specimen showed a lot of red-sphere materials in most cells cytoplasm. The Gomorra methenamine silver staining and PAS revealed the mucopolysaccharide-containing capsule of the Cryptococcus. Laboratory culture of lesion liquid grew a kind of yeast at 37°C. Cryptococcal femoral osteomyelitis was diagnosed at last. The patient is good now after the thorough debridement and anti-fungal treatment.

The aim of our report is to demonstrate the complementary roles of bone scintigraphy (BS), magnetic resonance imaging (MR), and positron emission tomography using 2-deoxy-2-[18F]fluoro-D-glucose (F-18-FDG PET/CT) in the diagnosis and treatment monitoring of a child with primary non-Hodgkin's lymphoma of bone (PLB). Increased blood flow, high tissue accumulation, and markedly increased uptake on the late BS pointed toward an active bone process in the left femoral region. Bone marrow infiltration of the left femur and cortical sclerosis, which were both demonstrated by MR imaging, were later confirmed as PLB by bone marrow biopsy. The normalizations of the flow and tissue phases of BS a year after treatment and during the entire follow-up were in keeping with inactive disease and clinical remission. However, even 8 years after treatment and complete remission, MR imaging demonstrated persistent unmodified bone marrow alteration and appreciable cortical involvement. A slightly increased metabolic activity of the left femoral epiphysis demonstrated by F-18-FDG PET/CT and mild activity in the same region on delayed BS were demonstrated in the late follow-up. Our results strongly suggest that BS and MR imaging should be included in the diagnostic algorithm of children with undefined bone symptoms. However, mild metabolic activity on the F-18-FDG PET/CT scan could not reliably differentiate between the presence or absence of disease in a patient with PLB in clinical remission.

Osteoma of long bone is an extremely rare, benign bone-forming surface lesion with the largest published case series consisting of only 14 patients. The most important and often most difficult lesion to differentiate from osteoma of long bone radiographically is parosteal osteosarcoma, which is a rare, low-grade surface osteosarcoma with the potential for dedifferentiation. Reports of imaging studies of osteoma of long bone depict a well-defined ossified mass arising from the surface of the diaphysis or metadiaphysis of a long bone. A characteristic feature is the homogeneity of the mass, with uniform density near or equal to that of cortical bone from the base of the lesion to its periphery. The 45-year-old female in this case presented with left hip fullness and was subsequently found to have a proximal femoral osteoma, which was unique in that it contained large fatty marrow spaces that corresponded to bands of relatively low density on plain radiography and computed tomography, giving it a heterogeneous appearance atypical of osteoma of long bone. Furthermore, the osteoma reported here was associated with a small but separate nodular focus of ossification in the adjacent soft tissue. These findings led to a presumptive diagnosis of parosteal osteosarcoma with a local soft tissue metastasis or satellite nodule resulting in radical resection of the tumor. Definitive diagnosis of osteoma was made on histology of both the parent lesion and ossified nodule as no neoplastic spindle cell proliferation was present to establish a diagnosis of low-grade osteosarcoma. This represents, to the best of our knowledge, the first such presentation of osteoma of long bone.

The bone liposclerosing myxofibrous tumor (LSMFT) was initially described by Ragsdale in 1986 as a polymorphic fibroosseous bone lesion with a mix of histologic elements that include lipoma, fibroxanthoma, myxoma, myxofibroma, fat necrosis, ischemic ossification, areas of fibrous dysplasia, and infrequent presence of cartilage or cystic changes. The most frequently reported location is the intertrochanteric area of the femur. Radiologically it is a lytic, geographic lesion, with well-defined margins and usually sclerotic. In some cases findings include mineralization inside the lesion or a certain degree of expansion to the contour. The close relationship between LSMFT and fibrous dysplasia has been described based on the histologic characteristics and the presence of the Gsα mutation. Another hypothesis of the etiology of the lesion is the reaction of fibrous dysplasia to stress.

Osteochondromas are the most common benign bone tumors. Vascular complications are unusual, with false arterial aneurysms being the majority among them. Although there are several reports of false aneurysms because of an exostosis in the femoro-popliteal region, cases presenting with a false aneurysm of the brachial artery are quite rare. Many suggestions have been made regarding prevention, diagnosis, and treatment of these false aneurysms, although there are no official guidelines. Therefore, this report aims to present 2 unusual cases of patients with a false aneurysm in the femoral and brachial artery, respectively, because of an exostosis. Literature data are discussed and useful conclusions regarding optimal management are made., (Copyright © 2015 Elsevier Inc. All rights reserved.)

This article presents the unusual case of a 58-year-old woman with a low-grade cardiac fibromyxosarcoma which was primarily surgically resected and treated with adjuvant chemotherapy. A pulmonary metastasis as well as osteolytic metastatic destruction of the right iliac crest occurred 3 years after primary diagnosis and 2 years later a bone metastasis of the left distal femur was detected. Applying a palliative treatment concept resection of the pulmonary metastasis and an extralesional resection of the bone metastasis of the right iliac crest with plastic reconstruction were performed. Afterwards resection of the left distal femur metastasis and prosthetic reconstruction with distal femur replacement could also be realized. Despite an initial poor prognosis a high quality of life without essential functional limitations could be maintained for more than 6 years in this individual case.

Background: We tried to compare the functional and psychosocial outcomes after various reconstruction methods according to tumor location following resection of osteosarcoma in distal femur., Methods: We retrospectively reviewed 51 patients who underwent limb-salvage surgery of osteosarcoma in distal femur in our institution, 30 males and 21 females with an average age of 21 years (range 13-51 years). We classified osteosarcoma in distal femur into 3 types, and organized affected limb reconstruction methods after wide resection. MSTS and QOL scores were used to analyze the functional and psychological outcomes., Results: After a mean follow-up of 43 months (12-225 months), there is no difference on functional results and QOL scores among three reconstruction groups (p > 0.05) and among three types groups (p > 0.05). No difference could be noticed on tumor-free survival and total survival among three reconstruction groups (p > 0.05) and three type groups (p > 0.05). In ≤2-year, better functional scores could be found in prosthesis group, rather than the other two inactivated-bone groups (p < 0.05)., Conclusions: Biological reconstruction with alcohol-inactivated autograft replantation could avoid prosthesis related complications and achieved comparable results with prosthesis following resection of osteosarcoma in distal femur. Different reconstruction options could be chosen according to tumor location, such as the distance to Insall line.

We report 2 cases of late recurrence of osteosarcoma after 6 and 7 years. One patient had pulmonary metastasis, and the other had soft tissue recurrence. Both patients underwent complete resection and chemotherapy. The first patient achieved complete remission and remained disease-free 47 months later and had no limitation in his daily life. The second patient had a re-recurrence and underwent further resection and chemotherapy. He remained disease-free 35 months later and could walk using a T-handled walking cane.

Background: Treatment of chondroblastoma in the femoral head is challenging owing to the particular location and its aggressive nature. There is little published information to guide the surgeon regarding the appropriate approach to treating a chondroblastoma in this location. We developed a modified trapdoor procedure to address this issue. The primary modification is that the window surface of the femoral head is covered by the ligamentum teres rather than cartilage as in the traditional procedure., Questions/purposes: We assessed (1) the clinical presentation of chondroblastoma of the femoral head and treatment results with the modified trapdoor procedure in terms of (2) the frequency of local recurrence, (3) complications, and (4) functional outcomes using the Musculoskeletal Tumor Society (MSTS) score., Methods: Between 1999 and 2010, we treated 14 patients for chondroblastoma of the femoral head. All patients received the modified trapdoor procedure. Of those, 13 were available for followup at a minimum of 36 months (mean, 66 months; range, 36-117 months) and one patient was lost to followup. There were nine males and four females, with a mean age of 18 years (range, 9-29 years). Clinical features were ascertained by chart and radiographic review, and recurrence, complications, and functional outcomes (MSTS score) were recorded from chart review. Patterns of bone destruction were evaluated using the Lodwick classification, which ranges from IA (geographic appearance with sclerotic rim) to III (permeative appearance)., Results: The symptoms at diagnosis were pain in nine patients and discomfort in four. The mean duration of symptom was 11 months (range, 1-36 months). The physis was open in two patients, closing in one, and closed in 10. The patterns of bone destruction were evaluated as Lodwick Class IA in six patients, Lodwick Class IB in five, and Lodwick Class IC in two. At latest followup, no local recurrence was observed. Two patients had postoperative complications. One had avascular necrosis of the femoral head and was treated with prosthesis replacement. The other had asymptomatic heterotopic ossification in the surgical field. The mean MSTS score was 29.6 (range, 28-30)., Conclusions: Based on this small series, we believe our modified trapdoor procedure is a safe, effective means of treating a chondroblastoma in the femoral head, but additional clinical evaluation with more patients is necessary to confirm our findings., Level of Evidence: Level IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Chondroblastoma is a rare benign bone tumor. The treatment for chondroblastoma usually consists of curettage of the lesion and packing the tumor cavity with bone grafts or bone cement. However, chondroblastomas are known to recur in 10% to 20% of cases after excision, possibly because the incomplete removal of pathological tissue at surgery. We present a case of chondroblastoma in the distal femur treated by endoscopic curettage, which allowed a complete resection of tumor tissue and a minimal damage of the bone. The patient had relief of symptoms, rapid function restoration and no local recurrence. Endoscopic curettage is a promising new treatment for chondroblastoma. In fact, the extra-articular technique enters the tumor cavity via a tunnel drilled through the medullary canal, allowing to visualize possible residual tumor tissue or defects of the articular surface, without violating the joint and without taking away a much bigger cortical window.

Context: Tumor-induced osteomalacia is curable if the tumors can be totally excised. However, when the tumors are present in locations that make surgery disproportionately risky, the need for less invasive strategies like radiofrequency ablation (RFA) is realized., Patients and Methods: We describe three patients with suspected tumor-induced osteomalacia who were treated in our department between 2006 and 2013 with tumors in surgically difficult locations and were subjected to single or multiple sessions of RFA. The response was documented in terms of symptomatic improvement, phosphorus normalization, and follow-up (99m)Technitium-labelled hydrazinonicotinyl-Tyr3-octreotide ((99m)Tc HYNIC TOC) scan., Results: Two of the three individuals, patient A (with a 1.5 × 1.2-cm lesion in the head of the right femur) and patient B (with a 1.3 × 1.2-cm lesion on the endosteal surface of the shaft of the left femur), achieved complete remission with single sessions of RFA. Three months after the procedure, (99m)Tc HYNIC TOC scans revealed the absence of uptake at the previous sites, corroborating with the clinical improvement and phosphorus normalization. Patient C had a large 5.6 × 6.5-cm complex lesion in the lower end of the left femur with irregular margins, loculations, and bone grafts placed in previous surgery. He failed to achieve remission after multiple sessions of RFA due to the complex nature of the lesion, although the tumor burden was reduced significantly as documented on serial (99m)Tc HYNIC TOC scans., Conclusions: Although surgery remains the treatment of choice, RFA could be an effective, less invasive, and safe modality of treatment in judiciously selected patients.

Primary malignant bone tumors, whether Ewing sarcoma or osteosarcoma, are a rare type of tumor. The sequential occurrence of two bone sarcomas, Ewing sarcoma and high-grade osteosarcoma, in the same patient at two different locations is an exceptionally rare phenomenon. We present the case of a 13-year-old girl who presented with a high-grade osteoblastic osteosarcoma of the distal femur, 7 years after treatment for Ewing sarcoma of the left pelvis. She did not receive radiation therapy. Following the recent developing multidisciplinary therapy, long-term follow-up for monitoring latent treatment-related adverse effects may be necessary for survivors of primary malignant bone tumors.

Osteochondroma is the most common benign tumor of the bone, seen mostly during adolescence. In the current study, we report a 19-year-old male patient with a two-week history of pain and swelling of the medial side of his right thigh just above the knee without any trauma. CT angiography revealed a popliteal artery pseudoaneurysm and its close relationship with a femoral osteochondroma. Surgical repair consisted of repair of pseudoaneurysm and removal of osteochondroma. In young patients, a non-traumatic pseudoaneurysm of distal femoral artery may be a complication of an osteochondroma and this treatable pathology should be looked for to prevent recurrence., (© The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.)

Pregnancy complicated by Non Hodgkin lymphoma (NHL) is rare, about 100 cases have been reported. We will describe the case of a multifocal bone lymphoma revealed by a left hyperalgetic and deficient cruralgia in a female in the second trimester of pregnancy.

Spontaneous hip dislocation due to intraarticular neurofibroma in patients with neurofibromatosis type 1 is extremely rare. We describe the imaging features of spontaneous dislocation of hip due to histologically proven intraarticular neurofibroma in young woman with neurofibromatosis type 1, and review the literature.

Giant cell tumor of bone is a benign, locally aggressive neoplasm that is composed of sheets of neoplastic mononuclear cells interspersed amongst non-neoplastic, uniformly distributed, osteoclast-like giant cells. They represent approximately 4-5% of primary bone tumors. Rarely, bone tumors have been noted to produce human chorionic gonadotropin, a finding most often reported in osteosarcoma. We present the case of a young woman who presented with a low-level human chorionic gonadotropin level which, after resection of her recurrent giant cell tumor of bone with secondary aneurysmal bone cyst-like change, became undetectable in her blood. Furthermore, cells within the aneurysmal bone cyst component were immunohistochemically positive for β-human chorionic gonadotropin. This is the first report of such a finding in the literature.