Inactivated Bone Replantation with Preservation of the Epiphysis in Children with Osteosarcoma:Clinical Report of Two Cases

Objective: To evaluate the value of inactivated bone replantation with preservation of the epiphysis following the effective chemotherapy in avoiding postoperative discrepancy of the affected limb in children with osteosarcoma. Methods: Two children (aged 5 and 10 years, 1 male and 1 female) with osteosarcoma underwent inactivated bone replantation with preserving epiphysis following chemotherapy (MMIA protocol, including high-dose methotrexate, adriamycin and ifosfamide). After two cycles of preop-erative chemotherapy, pain vanished, the local mass shrank and there was no pain on pressing the affected parts. Sera AKP and LDH were reduced to normal levels; marked shrinkage and sclerotic changes and good margin of lesions were seen on plain radiographs and MR images. Two courses of the same protocol as preoperative chemotherapy were administered postoperatively. Results: Postoperative histological examination of the specimens demonstrated absence of vital tumor cells. Incisions healed well and no complications occurred. The replanted inactivated bone healed with host at 6 months after operation. In the two patients, no evidence was seen of metastasis and recurrence and discrepancy of the affected limbs in postoperative 36 and 48 months. Functions of the affected limbs were satisfactory. Conclusion: Inactivated bone replantation with preserving epiphysis was a viable option for osteosarcoma in children. The long-term outcomes remain to be further proven.

Extraction, Purification and Identification of Bone Morphogenetic Protein in Conditioned Medium of Osteosarcoma Cell (MG-63)

Objective: To find out a method of extraction and purification of bone morphogenetic protein (BMP) from osteosarcoma cell conditioned medium, and evaluate the biological activity of BMP.Methods: Conditioned medium of osteosarcoma cell lines (MG-63) was collected, concentrated and dialyzed. The concentrated protein was purified through gel chromatography on Sephcryl-S-100. The purified protein was tested by BMP monoclonal antibody (McAb), its molecular weight (MW) was determined by SDS-PAGE and its biological activity was demonstrated by heterotopic ossification.Results: The purified protein was proved to be BMP by BMP McAb, had a satisfactory heterotopic ossification, and its MW was about 21 kD.Conclusion: BMP existed in the conditioned medium of osteosarcoma cell and had a satisfactory biological activity after purification. Because osteosarcoma cell can be cultured and grew for a long timein vitro, this method will be helpful to a vast extraction of BMP and clinical application. Key words osteosarcoma cell - conditioned medium - bone morphogenetic protein - protein purification This project was a key scientific and technological program of Hubei Provicial Scientific and Technological Committee (No. 002p1503).

Relationship between the Expression of MTA1 Gene and Invasion and Metastasis of Human Osteosarcoma Cells

Objective： To compare the expression level of metastasis associated-1 （MTA1） in the higher and lower metastasis sublines of human osteosarcoma cells （MG63）, and to investigate the relationship between the expression level of MTA1-EGFP and in vitro invasion and metastasis of human osteosarcoma cells. Methods： The expression level of MTA1 in two sublines of MG63 cells was detected by semi-quantitative RT-PCR, and cell invasion assay and cell proliferation assay were used to evaluate the invasive capacity in vitro in two sublines. The lower metastasis line of MG-63 cells were transfected with MTA1-EGFP full-length cDNA expression plasmid by lipofectamine. The changes of the MTA1-EGFP expression and in vitro invasion potential were measured after transfection. Results： M8 subline expressed significantly higher level of MTA1 than that of M6 subline by RT-PCR. The invasive potentials of low metastasis MG63 cell line were increased after MTA1 gene transfection. Conclusion： There may be a relationship between MTA1 and invasive potentials of human osteosarcoma cells, and MTA1 may play a role in the molecular mechanism of tumor metastases and be a potential target for gene therapy of osteosarcoma. Further studies of MTA1 in human ostersarcoma cell metastasis are needed.

Metastatic peritoneal sarcomatosis from radiation-induced osteosarcoma in a patient with previously treated pelvic Ewing’s sarcoma: Report of a case

Metastatic peritoneal sarcomatosis most commonly occurs from primary soft tissue sarcomas arising either within the abdomen or extremities. Metastatic peritoneal sarcomatosis from an osteosarcoma is extremely rare;only six cases have previously been reported. We report the first case of metastatic peritoneal sarcomatosis originating from radiation-induced osteoblastic osteosarcoma in a 22-year-old woman who had previously been treated for pelvic Ewing’s sarcoma. Abdominal computed tomography, bone scintigraphy and FDG PET/CT demonstrated extensive finely nodular disseminated peritoneal lesions. Histopathologic examination of these peritoneal lesions revealed osteosarcomatosis. In summary, we describe an unusual case of metastatic peritoneal sar comatosis from secondary osteosarcoma arising in a previously irradiated pelvicEwing’s sarcoma.

Low-grade central osteosarcoma of distal femur, resembling fibrous dysplasia

We report a case of a 32 year-old male, admitted for a lytic lesion of the distal femur. One month after the first X-ray, clinical and imaging deterioration was evident. Open biopsy revealed fibrous dysplasia. Three months later, the lytic lesion had spread to the whole distal third of the femur reaching the articular cartilage. The malignant clinical and imaging features necessitated excision of the lesion and reconstruction with a custom-made total knee arthroplasty. Intraoperatively, no obvious soft tissue infiltration was evident. Nevertheless, an excision of the distal 15.5 cm of the femur including 3.0 cm of the surrounding muscles was finally performed. The histological examination of the excised specimen revealed central low-grade osteosarcoma. Based on the morphological features of the excised tumor, allied to the clinical findings, the diagnosis of low-grade central osteosarcoma was finally made although characters of a fibrous dysplasia were apparent. Central low-grade osteosarcoma is a rare, well-differentiated sub-type of osteosarcoma, with clinical, imaging, and histological features similar to benign tumours. Thus, initial misdiagnosis is usual with the condition commonly mistaken for fibrous dysplasia. Central low-grade osteosarcoma is usually treated with surgery alone, with rare cases of distal metastases. However, regional recurrence is quite frequent after close margin excision.

PathVisio Analysis:An Application Targeting the miRNA Network Associated with the p53 Signaling Pathway in Osteosarcoma

MicroRNAs(miRNAs)are small single-stranded,non-coding RNA molecules involved in the pathogenesis and progression of cancer,including osteosarcoma.We aimed to clarify the pathways involving miRNAs using new bioinformatics tools.We applied WikiPathways and PathVisio,two open-source platforms,to analyze miRNAs in osteosarcoma using miRTar and ONCO.IO as integration tools.We found 1298 records of osteosarcoma papers associated with the word“miRNA”.In osteosarcoma patients with good response to chemotherapy,miR-92a,miR-99b,miR-193a-5p,and miR-422a expression is increased,while miR-132 is decreased.All identified miRNAs seem to be centered on the TP53 network.This is the first application of PathVisio to determine miRNA pathways in osteosarcoma.MiRNAs have the potential to become a useful diagnostic and prognostic tool in the management of osteosarcoma.PathVisio is a full pathway editor with the potentiality to illustrate the biological events,augment graphical elements,and elucidate all the physical structures and interactions with standard external database identifiers.

Molecular pathogenesis and therapeutic strategies of human osteosarcoma

Osteosarcoma（OS）is a devastating illness with rapid rates of dissemination and a poor overall prognosis,despite aggressive standard-of-care surgical techniques and combination chemotherapy regimens.Identifying the molecular mechanisms involved in disease pathogenesis and progression may offer insight into new therapeutic targets.Defects in mesenchymal stem cell differentiation,abnormal expression of oncogenes and tumor suppressors,and dysregulation within various important signaling pathways have all been implicated in development of various disease phenotypes.As such,a variety of basic science and translational studies have shown promise in identifying novel markers and modulators of these disease-specific aberrancies.Born out of these and similar investigations,a variety of emerging therapies are now undergoing various phases of OS clinical testing.They broadly include angiogenesis inhibitors,drugs that act on the bone microenvironment,receptor tyrosine kinase inhibitors,immune system modulators,and other radio-or chemo-sensitizing agents.As new forms of drug delivery are being developed simultaneously,the possibility of targeting tumors locally while minimizing systemic toxicityis is seemingly more achievable now than ever.In this review,we not only summarize our current understanding of OS disease processes,but also shed light on the multitude of potential therapeutic strategies the scientific community can use to make long-term improvements in patient prognosis.

Local recurrence of a parosteal osteosarcoma 21 years after incomplete resection

Parosteal osteosarcoma (POS) is the most common form of surface osteosarcoma. Its symptoms are insidious and its duration prior to diagnosis is considerably longer than that of other types of osteosarcoma. We report a case of POS with a growing mass but no evidence of metastasis. This tumor, which was diagnosed as calcified hematoma with benign characteristics, was incompletely resected in our hospital 21 years before the diagnosis of recurrence. The patient underwent a wide en bloc resection in our hospital and was free of symptoms, with no signs of tumor recurrence or metastasis during a 53-month follow-up.

Exosomes derived from pulmonary metastatic sites enhance osteosarcoma lung metastasis by transferring the miR-194/215 cluster targeting MARCKS

Osteosarcoma,a prevalent primary malignant bone tumor,often presents with lung metastases,severely impacting patient survival rates.Extracellular vesicles,particularly exosomes,play a pivotal role in the formation and progression of osteosarcoma-related pulmonary lesions.However,the communication between primary osteosarcoma and exosome-mediated pulmonary lesions remains obscure,with the potential impact of pulmonary metastatic foci on osteosarcoma progression largely unknown.This study unveils an innovative mechanism by which exosomes originating from osteosarcoma pulmonary metastatic sites transport the miR-194/215 cluster to the primary tumor site.This transportation enhances lung metastatic capability by downregulating myristoylated alanine-rich C-kinase substrate(MARCKS)expression.Addressing this phenomenon,in this study we employ cationic bovine serum albumin(CBSA)to form nanoparticles(CBSA-anta-194/215)via electrostatic interaction with antagomir-miR-194/215.These nanoparticles are loaded into nucleic acid-depleted exosomal membrane vesicles(anta-194/215@Exo)targeting osteosarcoma lung metastatic sites.Intervention with bioengineered exosome mimetics(anta-194/215@Exo)not only impedes osteosarcoma progression but also significantly prolongs the lifespan of tumor-bearing mice.These findings suggest that pulmonary metastatic foci-derived exosomes initiate primary osteosarcoma lung metastasis by transferring the miR-194/215 cluster targeting MARCKS,making the miR-194/215 cluster a promising therapeutic target for inhibiting the progression of patients with osteosarcoma lung metastases.

Transition from Tumor Tissue to Bone Marrow in Patients with Appendicular Osteosarcoma after Neoadjuvant Chemotherapy

Background：Limb-salvage surgery is the standard procedure for the treatment of appendicular osteosarcoma.Precise resection is the trend in limb-salvage surgery.The aim of this study was to evaluate a large series of cases to identify the histological relationship between the tumor and marrow and determine the intramedullary transition type and width from the tumor to normal marrow in patients with osteosarcoma after neoadjuvant chemotherapy.Methods：One hundred and six osteosarcoma specimens were evaluated.The tissue specimens were sectioned through the coronal axis by an electronic saw.The tissue was immersed in formalin solution for fixation and subsequently decalcified.The interface between the tumor and normal bone marrow was grossly determined and submitted for microscopic evaluation to detect the relationship between the tumor and bone marrow and identify the transition type and width.All histological slides were examined by experienced orthopedic pathologists.Results：Histologically,the interface between the tumor and normal bone marrow was classified into two patterns：＂clear＂ and ＂infiltrated.＂The clear pattern,characterized by a clear boundary between the tumor and marrow,was identified in sixty cases （56.6%）.A subtype of the clear type,characterized by fibrous bands between the tumor and marrow,was found in 13 cases （12.3%）.The infiltrated pattern,characterized by a boundary with tumor cell clusters embedded in the marrow,was found in 46 cases （43.4%）.The infiltrating depth varied from 1 to 4 mm （mean,2.6 ＋ 0.7 mm）.No tumor cells were observed in the normal bone marrow areas next to the interface.Conclusions：The transition from osteosarcoma tissue to bone marrow after neoadjuvant chemotherapy can be divided into two histological patterns：clear and infiltrated.The greatest infiltration width was 4 mm from tumor to normal marrow in this study.This depth should be considered in the presurgical plan.

Research progress in the mechanism and treatment of osteosarcoma

Osteosarcoma(OS)is the most common primary malignant bone tumor that more commonly occurs in children and adolescents.The most commonly used treatment for OS is surgery combined with chemotherapy,but the treatment outcomes are typically unsatisfactory.High rates of metastasis and post-treatment recurrence rates are major challenges in the treatment of OS.This underlines the need for studying the in-depth characterization of the pathogenetic mechanisms of OS and development of more effective therapeutic modalities.Previous studies have demonstrated the important role of the bone microenvironment and the regulation of signaling pathways in the occurrence and development of OS.In this review,we discussed the available evidence pertaining to the mechanisms of OS development and identified therapeutic targets for OS.We also summarized the available treatment modalities for OS and identified future priorities for therapeutics research.

Tumor blood vessels formation in osteosarcoma:vasculogenesis mimicry

BACKGROUND: Osteosarcoma is characterized by high neovascularization and a high propensity for metastasis through bloodstream. This study was to examine whether there is evidence for vasculogenic mimicry in osteosarcoma and to illustrate mechanism of tumor blood vessels formation in osteosarcoma. METHODS: Osteosarcoma cell lines (U-2OS) were tested for their ability to form tubular networks in three-dimensional culture containing type I collagen. The structures of the tubular networks were observed with phase contrast microscope and transmission electron microscope (TEM). Morphometric studies using hematoxylin and eosin (HE) stain and CD31 immunohistochemical stain to show tumor-lined channels in human osteosarcoma were also performed. RESULTS: Observation with light microscope and TEM showed that highly aggressive osteosarcoma cell lines (U-2OS) formed networks containing channels when grown in three-dimensional culture containing type I collagen, in the absence of endothelial cells or fibroblasts. Morphometric observation using HE stain and CD31 immunohistochemical stain showed that tumor cell-lined channels were also detected in vivo in osteosarcoma; by comparison, all vascular areas in the pedicle of osteochondroma or outside osteochondroma were endothelial-lined. CONCLUSION: These observations strongly suggest that aggressive osteosarcoma cells may generate vascular channels that facilitate tumor perfusion independent of tumor angiogenesis and have the ability of vasculogenic mimicry.

血清BALP/TALP比值诊断儿童和青少年骨肉瘤的临床意义

目的分析血清骨型碱性磷酸酶(BALP)/总碱性磷酸酶(TALP)比值用于诊断儿童和青少年骨肉瘤的价值及预测预后的意义。方法回顾性纳入2018年9月至2021年9月间在北京大学人民医院骨肿瘤科接受治疗的200例四肢骨肉瘤患者(骨肉瘤组),以及同期就诊的50例良性骨肿瘤患者(良性骨肿瘤组)及50例正常对照者(对照组)。采用化学发光免疫分析仪检测血清中BALP和TALP含量,并计算BALP/TALP。比较其含量与骨肉瘤临床病理特征的关系。采用受试者工作曲线(ROC)评价BALP/TALP诊断骨肉瘤的效能,并计算曲线下面积(AUC)。Kaplan-meier法绘制生存曲线,生存差异行Log-rank检验。采用Cox风险比例回归模型分析影响骨肉瘤预后的因素。结果骨肉瘤组血清BALP、TALP、BALP/TALP分别为71.52 IU/L(44.26,135.68)、192.00 IU/L(162.00,233.50)和0.37(0.21,0.67),均高于良性骨肿瘤组、健康对照组,差异具有统计学意义(P<0.05)。血清BALP/TALP水平诊断骨肉瘤的灵敏度为82.0%、特异度为89.5%,约登指数为0.715,截断值为0.19,AUC为0.925(95%CI:0.901~0.949,P<0.001)。血清BALP/TALP水平与肿瘤直径、分化程度、组织学类型、Enneking分期和局部/远隔转移等有关(P<0.05);与年龄、性别、肿瘤位置、Huvos分级等均无关。血清BALP/TALP水平≥0.37的骨肉瘤患者中位生存期低于血清BALP/TALP水平<0.37者(P<0.05)。Cox风险比例回归模型分析,血清BALP/TALP水平≥0.37为影响骨肉瘤患者预后的独立危险因素(P=0.001)。结论血清BALP/TALP水平诊断儿童与青少年骨肉瘤效能较高,且能有效预测预后。

3D氨基质子转移加权成像联合弥散加权成像鉴别良、恶性骨与软组织肿瘤

目的探讨3D氨基质子转移加权成像(APTWI)、弥散加权成像(DWI)及二者联合鉴别良、恶性骨与软组织肿瘤的价值。方法前瞻性对96例骨盆或下肢骨与软组织肿瘤患者采集平扫MRI、APTWI及DWI。分别基于APTWI及DWI获得偏移量为3.5 ppm的非对称性磁化传递率(MTRasym)图及表观弥散系数(ADC)图,测量病灶MTRasym(3.5 ppm)最大值(MTRasym_(max))、均值(MTRasym_(mean))及最小值(MTRasym_(min)),以及ADC最大值(ADC_(max))、均值(ADC_(mean))及最小值(ADC_(min));比较良、恶性肿瘤各参数差异,绘制受试者工作特征曲线,计算曲线下面积(AUC),评估APTWI、DWI及二者联合的鉴别诊断效能。结果96例中,良性41例、恶性55例。恶性肿瘤MTRasym(MTRasym_(max)、MTRasym_(mean)和MTRasym_(min))均明显高于,而ADC(ADC_(max)、ADC_(mean)和ADC_(min))均明显低于良性肿瘤(P均<0.05)。MTRasym_(max)和ADC_(min)鉴别良、恶性肿瘤的AUC分别为0.791和0.873,差异无统计学意义(P=0.122);二者联合的AUC为0.944,高于单一项(P<0.001、P=0.041)。结论APTWI联合DWI鉴别良、恶性骨与软组织肿瘤的效能较高。

动态对比增强MRI评估化学治疗用于兔VX2恶性骨肿瘤模型早期效果

目的观察动态对比增强MRI(DCE-MRI)评估化学治疗(简称化疗)用于兔VX2恶性骨肿瘤模型早期效果的价值。方法以30只实验兔成功建立VX2恶性骨肿瘤模型,以其中14只为化疗组,经静脉注射顺铂7 mg/kg体质量,以另16只为对照组,经静脉注射等量生理盐水。分别于造模2周后(干预前)及干预后3天采集平扫MRI及DCE-MRI,对MRI与病理所见进行点对点对照,获取瘤体区域容积转移常数(K^(trans))、速率常数(K_(ep))、血管外细胞外容积分数(V_(e))及血浆容积分数(V_(p)),以及微血管密度(MVD)。比较组内干预前、后MRI结果,以及干预后组间MRI结果,以受试者工作特征(ROC)曲线及曲线下面积(AUC)评估各参数判断是否曾接受化疗的效能,分析干预后DCE-MRI各参数与MVD的相关性。结果化疗组干预前、后平扫MRI所见肿瘤最大径差异无统计学意义(P>0.05)。相比干预前,化疗组实体瘤区域K^(trans)、K_(ep)均降低、对照组均升高(P均<0.05),而2组V_(e)及V_(p)差异均无统计学意义(P均>0.05)。干预后化疗组K^(trans)及K_(ep)值均低于对照组(P均<0.05),而组间V_(e)及V_(p)差异均无明显统计学意义(P均>0.05)。以K^(trans)、K_(ep)、V_(e)及V_(p)判断是否曾接受化疗的AUC分别为0.964、0.933、0.317及0.455。干预后化疗组实体瘤区域MVD低于对照组(P<0.05);2组实体瘤区域K^(trans)、K_(ep)值均与MVD呈正相关(r=0.876、0.881,P均<0.05),而V_(e)或V_(p)值与MVD无显著相关性(r=0.118、0.202,P均>0.05)。结论DCE-MRI定量分析参数K^(trans)和K_(ep)可较为敏感地反映化疗用于VX2恶性骨肿瘤模型兔早期效果及其MVD变化。

乳腺癌细胞条件培养基对骨髓间充质干细胞生物学行为的影响

目的探讨MCF-7乳腺癌细胞条件培养基对骨髓间充质干细胞(BMSC)增殖、凋亡和迁移的影响及分子机制。方法正常环境下培养的BMSC为对照组,以MCF-7细胞条件培养基培养的BMSC为MCF-7条件培养基组,向MCF-7条件培养基组添加10 nmol/L GSK690693(Akt抑制剂)为Akt抑制剂组,向MCF-7条件培养基组添加10µmol/L Reparixin(CXCR1/2抑制剂)为CXCR1/2抑制剂组。MTT实验检测各组BMSC增殖情况,Annexin V-FITC/PI双标记流式细胞凋亡实验检测各组BMSC凋亡率,Transwell细胞迁移实验检测各组BMSC的迁移能力,酶联免疫吸附试验检测两种细胞培养上清液和MCF-7细胞条件培养基中白细胞介素(IL)-8蛋白含量,Western blot检测各组BMSC的蛋白激酶B(Akt)/磷酸化Akt(p-Akt)和哺乳动物雷帕霉素靶蛋白(mTOR)/磷酸化mTOR(p-mTOR)蛋白表达。结果与对照组相比,MCF-7条件培养基组BMSC的细胞增殖水平、迁移数目以及p-Akt和p-mTOR蛋白相对表达量均增高,细胞凋亡率降低(P<0.05);与MCF-7条件培养基组相比,CXCR1/2抑制剂组和Akt抑制剂组BMSC的细胞增殖水平、迁移数目以及p-Akt和p-mTOR蛋白相对表达量均降低,细胞凋亡率增加(P<0.05);MCF-7细胞条件培养基和MCF-7培养上清液中IL-8蛋白含量均较BMSC培养上清液中IL-8蛋白含量高(P<0.05)。结论MCF-7细胞条件培养基通过激活Akt-mTOR信号通路促进BMSC增殖和迁移,抑制BMSC凋亡,其中IL-8-CXCR1/2轴发挥关键作用。

少见部位骨肉瘤的影像学表现

目的探讨少见部位骨肉瘤的影像学表现,以提高对本病的认识。方法回顾性分析经病理证实的13例少见部位骨肉瘤的临床病例资料及影像学表现,结合文献总结其临床及影像学表现。全部13例患者行X线平片和CT检查,其中7例行CT增强扫描,8例行MRI检查,其中6例行MRI动态增强检查。结果肿瘤发生于骨盆4例,上颌骨3例,肩胛骨2例,胫骨干1例,胫骨远端1例,跟骨1例,尺骨干1例。影像表现为溶骨型6例,成骨型5例,混合型2例。出现广泛骨质破坏9例,骨膜反应2例,软组织肿块9例,瘤骨或肿瘤样钙化11例。CT较X线能更直观地显示病变位置及其与毗邻结构关系,在显示骨质破坏、骨膜反应及瘤骨和瘤样钙化方面具有较大优势。MRI在判断肿瘤的位置、大小、累及范围方面较CT有优势,能清晰显示髓腔及周围软组织的侵犯蔓延程度、软组织肿块的形成。结论少见部位的骨肉瘤多发生于中老年人患者,影像学表现以溶骨型骨肉瘤较为多见,病灶内出现瘤骨或肿瘤样钙化是诊断的关键,X线、CT和MRI三者结合有助于本病的诊断与鉴别诊断。

以骨肉瘤形态为主的原发性恶性骨巨细胞瘤7例临床病理分析

目的探讨以骨肉瘤形态为主原发性恶性骨巨细胞瘤(primary malignant giant cell tumor of bone,PMGCTB)的临床病理学特征。方法回顾性分析7例PMGCTB的临床病理特征。结果7例PMGCTB中,女性4例,男性3例,年龄9~66岁(平均39.5岁,中位年龄35岁)。发生部位以股骨骨端最常见(3/6),临床表现为病变部位的疼痛和肿胀。影像学表现为溶骨性占位、溶骨和硬化混合性占位为主;多数骨皮质破坏伴软组织肿块形成(5/7)。组织学均以普通型骨肉瘤形态为主,破骨细胞样多核巨细胞完全消失或少量存在。免疫表型:6例肿瘤细胞H3F3A G34W核阳性、1例H3F3A G34V核阳性,所有肿瘤均表达SATB2、p63,p53呈野生型,Ki67增殖指数10%~50%。所有病例均发现H3F3A基因改变,6例为H3F3A p.G34W突变,1例为H3F3A p.G34V突变。结论PMGCTB罕见,当缺乏经典骨巨细胞瘤组织学特征时诊断更具挑战性,需结合影像学、免疫表型及分子检测,并注意与骨肉瘤及其他高级别肉瘤相鉴别。

Florid reactive periostitis ossificans of the humerus: Case report and differential diagnosis of periosteal lesions of long bones

A case of florid reactive periostitis ossificans(RPO) arising in a long bone is presented. This is a rare bone proliferation with a pronounced periosteal reaction. Less than 100 cases have been described in the literature with far fewer outside the bones of the hand, feet, fingers, and toes. Although the etiology is unknown, a relationship to preceding trauma is suggested. The imaging and histologic features show an overlap with other bone lesions including bizarre parosteal osteochondromatous proliferation, subungual exostosis, and malignant surface tumors of bone and cartilage which include, periosteal and parosteal osteosarcoma. It is important to recognize the clinical presentation and diagnostic features of RPO as a benign entity so that it is not mistaken for a more aggressive neoplasm. We present a case of a right distal humeral lesion that on histopathological review revealed florid RPO. This diagnosis was not suspected on imaging studies, but was made on open biopsy of the mass. The patient remains disease free, years postoperatively. In addition to presenting this unique case report, we review the pertinent literature, and offer a differential diagnosis and treatment strategy for its management.

儿童膝关节周围骨肉瘤灭活再植与假体置换的短期疗效对比

目的探讨儿童膝关节周围骨肉瘤瘤段灭活再植术与全膝关节肿瘤假体置换术的短期疗效差异。方法回顾性分析2019年1月至2022年1月就诊于新疆医科大学附属肿瘤医院骨与软组织肿瘤及黑色素瘤科,行保留骨骺的瘤段灭活再植术和全膝关节肿瘤假体置换术的膝关节周围骨肉瘤26例患者的临床资料,男13例,女13例;年龄8~16岁,平均(11.88±2.42)岁。其中采用瘤段灭活再植手术8例(股骨5例,胫骨3例),为灭活再植组;采用全膝关节肿瘤假体置换手术方式共18例(股骨9例,胫骨9例),为假体置换组。比较两组患者一般临床资料,功能评估采用肌肉骨骼肿瘤协会评分(musculoskeletal tumor society,MSTS),使用膝关节活动度评分(range of motion,ROM)评估膝关节活动范围,术后定期复查X线片评估双下肢长度差异,进行肿瘤学评估以及并发症评估等。结果26例膝关节周围骨肉瘤患者,随访20~56个月,平均(29.50±6.46)个月。灭活再植组中双下肢长度差异0.63~1.75 cm,平均(1.03±0.37)cm;假体置换组中双下肢长度差异0.73~4.00 cm,平均(1.96±0.88)cm,两组比较差异有统计学意义(t=2.86,P=0.009)。MSTS评分灭活再植组平均为(26.63±1.51)分,假体置换组平均为(24.50±1.89)分,两组MSTS评分比较,差异有统计学意义(t=2.81,P=0.01)。瘤段灭活再植组中末次随访膝关节屈曲角度平均为健侧的(62.13±13.78)%;全膝关节肿瘤假体置换组末次随访膝关节屈曲角度平均为健侧的(65.68±10.40)%,两组患者膝关节屈曲角度比较,差异无统计学意义(χ2=1.25,P=0.26)。结论儿童膝关节周围骨肉瘤瘤段灭活再植保留骨骺能够有效保留患肢的生长发育潜能,改善患者关节功能,植骨融合较好,并发症较少,短期随访具有较好的临床疗效。