Enchondroma and chondrosarcoma

Prevalence and characteristics of benign cartilaginous tumours of the shoulder joint. An MRI-based study

OBJECTIVE

Enchondromas (EC) of the shoulder joint are benign intraosseous cartilage neoplasms, with atypical cartilaginous tumours (ACT) representing their intermediate counterpart. They are usually found incidentally on clinical imaging performed for other reasons. Thus far the prevalence of ECs of the shoulder has been analysed in only one study reaching a figure of 2.1%.

MATERIALS AND METHODS

The aim of the current study was to validate this number via retrospective analysis of a 45 times larger, uniform cohort consisting of 21.550 patients who had received an MRI of the shoulder at a single radiologic centre over a time span of 13.2 years.

RESULTS

Ninety-three of 21.550 patients presented with at least one cartilaginous tumour. Four patients showed two lesions at the same time resulting in a total number of 97 cartilage tumours (89 ECs [91.8%], 8 ACTs [8.2%]). Based on the 93 patients, the overall prevalence was 0.39% for ECs and 0.04% for ACTs. Mean size of the 97 ECs/ACTs was 2.3 ± 1.5 cm; most neoplasms were located in the proximal humerus (96.9%), in the metaphysis (60.8%) and peripherally (56.7%). Of all lesions, 94 tumours (96.9%) were located in the humerus and 3 (3.1%) in the scapula.

CONCLUSION

Frequency of EC/ACT of the shoulder joint appears to have been overestimated, with the current study revealing a prevalence of 0.43%.

Risk factors for distant metastasis of chondrosarcoma: A population-based study

Chondrosarcoma is the second largest bone malignancy after osteosarcoma and mainly affects middle-aged adults, where patients with distant metastasis (DM) often have a poor prognosis. Although nomograms have been widely used to predict distant tumor metastases, there is a lack of large-scale data studies for the diagnostic evaluation of DM in chondrosarcoma. Data on patients diagnosed with chondrosarcoma from 2004 to 2015 were obtained from the Surveillance, Epidemiology, and End Results database. Independent risk factors for having DM from chondrosarcoma were screened using univariate and multivariate logistics regression analysis. A nomogram was created to predict the probability of DM from the screened independent risk factors. The nomogram was then validated using receiver operating characteristic curves and calibration curves. A total of 1870 chondrosarcoma patients were included in the study after data screening, of which 157 patients (8.40%) had DM at the time of diagnosis. Univariate and multivariate logistic regression analysis screened four independent risk factors, including grade, tumor number, T stage, and N stage. receiver operating characteristic curves and calibration curves showed good accuracy of the nomogram in both training and validation sets. The current study screened for independent risk factors for DM from chondrosarcoma, which will help clinicians evaluate patients.

Prevalence and characteristics of benign cartilaginous tumours of the knee joint as identified on MRI scans

BACKGROUND

Enchondromas (EC) and atypical cartilaginous tumours (ACT) of the knee joint represent benign/intermediate chondromatous neoplasms of the bone that are most commonly discovered incidentally. Based on small to intermediate-sized cohorts, the prevalence of cartilaginous tumours of the knee as visible in MRI is estimated at 0.2-2.9%. This study aimed at verifying/challenging these numbers via retrospective examination of a larger, uniform patient cohort.

METHODS

Between 01.01.2007 and 01.03.2020, 44,762 patients had received an MRI of the knee for any indication at a radiologic centre. Of these, 697 patients presented with MRI reports positive for cartilaginous lesions. In a three-step workflow, 46 patients were excluded by a trained co-author, a radiologist and an orthopaedic oncologist, as wrongly being diagnosed for a cartilage tumour.

RESULTS

Of 44,762 patients, 651 presented with at least one EC/ACT indicating a prevalence of 1.45% for benign/intermediate cartilaginous tumours of the knee joint (EC: 1.4%; ACTs: 0.05%). As 21 patients showed 2 chondromatous lesions, altogether 672 tumours (650 ECs [96.7%] and 22 ACTs [3.3%]) could be analysed in terms of tumour characteristics: With a mean size of 1.6 ± 1.1 cm, most lesions were located in the distal femur (72.9%), in the metaphysis of the respective bone (58.9%) and centrally in the medullary canal (57.4%).

CONCLUSIONS

This study revealed an overall prevalence of 1.45% for cartilage lesions around the knee joint. Whilst a constant increase in prevalence was found for ECs over 13.2 years, prevalence remained constant for ACTs.

Chondroid Tumors: Review of Salient Imaging Features and Update on the WHO Classification

Chondrogenic tumors are typically well recognized on radiographs, but differentiation between benign and malignant cartilaginous lesions can be difficult both for the radiologist and for the pathologist. Diagnosis is based on a combination of clinical, radiological and histological findings. While treatment of benign lesions does not require surgery, the only curative treatment for chondrosarcoma is resection. This article (1) emphasizes the update of the WHO classification and its diagnostic and clinical effects; (2) describes the imaging features of the various types of cartilaginous tumors, highlighting findings that can help differentiate benign from malignant lesions; (3) presents differential diagnoses; and (4) provides pathologic correlation. We attempt to offer valuable clues in the approach to this vast entity.

The diagnostic value of magnetic resonance imaging-based texture analysis in differentiating enchondroma and chondrosarcoma

OBJECTIVE

To assess the diagnostic performance of MRI-based texture analysis for differentiating enchondromas and chondrosarcomas, especially on fat-suppressed proton density (FS-PD) images.

MATERIALS AND METHODS

The whole tumor volumes of 23 chondrosarcomas and 24 enchondromas were manually segmented on both FS-PD and T1-weighted images. A total of 861 radiomic features were extracted. SelectKBest was used to select the features. The data were randomly split into training (n = 36) and test (n = 10) for T1-weighted and training (n = 37) and test (n = 10) for FS-PD datasets. Fivefold cross-validation was performed. Fifteen machine learning models were created using the training set. The best models for T1-weighted, FS-PD, and T1-weighted + FS-PD images were selected in terms of accuracy and area under the curve (AUC).

RESULTS

There were 7 men and 16 women in the chondrosarcoma group (mean ± standard deviation age, 45.65 ± 11.24) and 7 men and 17 women in the enchondroma group (mean ± standard deviation age, 46.17 ± 11.79). Naive Bayes was the best model for accuracy and AUC for T1-weighted images (AUC = 0.76, accuracy = 80%, recall = 80%, precision = 80%, F1 score = 80%). The best model for FS-PD images was the K neighbors classifier for accuracy and AUC (AUC = 1.00, accuracy = 80%, recall = 80%, precision = 100%, F1 score = 89%). The best model for T1-weighted + FS-PD images was logistic regression for accuracy and AUC (AUC = 0.84, accuracy = 80%, recall = 60%, precision = 100%, F1 score = 75%).

CONCLUSION

MRI-based machine learning models have promising results in the discrimination of enchondroma and chondrosarcoma based on radiomic features obtained from both FS-PD and T1-weighted images.

Classification of Chondrosarcoma: From Characteristic to Challenging Imaging Findings

Chondrosarcomas can be classified into various forms according to the presence or absence of a precursor lesion, location, and histological subtype. The new 2020 World Health Organization (WHO) Classification of Tumors of Soft Tissue and Bone classifies chondrogenic bone tumors as benign, intermediate (locally aggressive), or malignant, and separates atypical cartilaginous tumors (ACTs) and chondrosarcoma grade 1 (CS1) as intermediate and malignant tumors. respectively. Furthermore, the classification categorizes chondrosarcomas (including ACT) into eight subtypes: central conventional (grade 1 vs. 2–3), secondary peripheral (grade 1 vs. 2–3), periosteal, dedifferentiated, mesenchymal, and clear cell chondrosarcoma. Most chondrosarcomas are the low-grade, primary central conventional type. The rarer subtypes include clear cell, mesenchymal, and dedifferentiated chondrosarcomas. Comprehensive analysis of the characteristic imaging findings can help differentiate various forms of chondrosarcomas. However, distinguishing low-grade chondrosarcomas from enchondromas or high-grade chondrosarcomas is radiologically and histopathologically challenging, even for experienced radiologists and pathologists.

Differentiating Enchondromas and Atypical Cartilaginous Tumors in Long Bones with Computed Tomography and Magnetic Resonance Imaging

The differentiation between the atypical cartilaginous tumor (ACT) and the enchondromas is crucial as ACTs require a curettage and clinical as well as imaging follow-ups, whereas in the majority of cases enchondromas require neither a treatment nor follow-ups. Differentiating enchondromas from ACTs radiologically remains challenging. Therefore, this study evaluated imaging criteria in a combination of computed tomography (CT) and magnetic resonance (MR) imaging for the differentiation between enchondromas and ACTs in long bones. A total of 82 patients who presented consecutively at our institution with either an ACT (23, age 52.7 ±18.8 years; 14 women) or an enchondroma (59, age 46.0 ± 11.1 years; 37 women) over a period of 10 years, who had undergone preoperative MR and CT imaging and subsequent biopsy or/and surgical removal, were included in this study. A histopathological diagnosis was available in all cases. Two experienced radiologists evaluated several imaging criteria on CT and MR images. Likelihood of an ACT was significantly increased if either edema within the bone (p = 0.049), within the adjacent soft tissue (p = 0.006) or continuous growth pattern (p = 0.077) were present or if the fat entrapment (p = 0.027) was absent on MR images. Analyzing imaging features on CT, the likelihood of the diagnosis of an ACT was significantly increased if endosteal scalloping >2/3 (p < 0.001), cortical penetration (p < 0.001) and expansion of bone (p = 0.002) were present and if matrix calcifications were observed in less than 1/3 of the tumor (p = 0.013). All other imaging criteria evaluated showed no significant influence on likelihood of ACT or enchondroma (p > 0.05). In conclusion, both CT and MR imaging show suggestive signs which can help to adequately differentiate enchondromas from ACTs in long bones and therefore can improve diagnostics and consequently patient management. Nevertheless, these features are rare and a combination of CT and MR imaging features did not improve the diagnostic performance substantially.

One-stage En bloc resection of thoracic spinal chondrosarcoma with huge paravertebral mass through the single posterior approach by dissociate longissimus thoracis

Study design

Retrospective case series.

Objective

To describe the technique details and therapeutic outcomes of 3-D printing model-guided en bloc resection of chondrosarcoma (CHS) with huge paravertebral mass via the combined posterior median and Wiltse approach.

Summary of background data

Total en bloc spondylectomy (TES) technique is conventionally based on the single posterior approach or combined anterior-posterior approach. However, the single posterior approach imposes a high technical demand on the surgeon due to the narrow field of vision, limited surgical space and the delicate spinal cord, while the combined anterior-posterior approach not only requires greater patient tolerance but is time consuming and runs the risk of more blood loss and injury to the visceral pleura and large blood vessels during surgery. In addition, it is difficult to completely remove the thoracic CHS with paravertebral mass through simple en bloc resection when it involves the aorta, vena cava, costa and lung.

Material and methods

Between August 2010 and January 2016, we performed a retrospective study to evaluate the clinical characteristics and outcomes of en bloc resection of thoracic spinal CHS with paravertebral mass through the combined posterior median and Wiltse approach. Postoperative recurrence-free survival (RFS) and overall survival (OS) were estimated by the Kaplan-Meier method. P values less than 0.05 were considered statistically significant.

Results

Altogether 15 patients received en bloc resection of thoracic spinal CHS with paravertebral mass through the combined posterior median and Wiltse approach. The mean age of these patients was 37.0 ± 12.8 years (median 36; range 15–64). This combination approach provided more extensive exposure and wider marginal resection of the tumor within a mean operation duration of 288 ± 96 min (median 280; range 140–480) and mean intraoperative blood loss of 1,966 ± 830 ml (median 2,000; range 300–3,000). Of the 15 patients, 5 experienced local recurrence of the disease; the mean time from surgery to recurrence was 22 ± 9.85 months (median 17, range 13–35). RFS in patients with recurrent CHS was significantly lower than that in patients with primary CHS on admission (p = 0.05).

Conclusions

The combined posterior median and Wiltse approach is a technically viable option for en bloc resection of thoracic spinal CHS with huge paravertebral mass, and can give a favorable local control of CHS.

Level of evidence

Level V.

Update on the imaging features of the enchondromatosis syndromes

Ollier disease and Maffucci syndrome are the commonest enchondromatosis subtypes, arising from non-hereditary mutations in the IDH1 and IDH2 genes, presenting in childhood and being characterised by multiple enchondromas. Maffucci syndrome also includes multiple soft tissue haemangiomas. Aside from developing bony masses, osseous deformity and pathological fracture, ~ 40% of these patients develop secondary central chondrosarcoma, and there is increased risk of non-skeletal malignancies such as gliomas and mesenchymal ovarian tumours. In this review, we outline the molecular genetics, pathology and multimodality imaging features of solitary enchondroma, Ollier disease and Maffucci syndrome, along with their associated skeletal complications, in particular secondary chondrosarcoma. Given the lifelong risk of malignancy, imaging follow-up will also be explored. Metachondromatosis, a rare enchondromatosis subtype characterised by enchondromas and exostoses, will also be briefly outlined.

Benign Bone Tumors: An Overview of What We Know Today

Nonmalignant bone tumors represent a wide variety of different entities but maintain many common features. They usually affect young patients, and most can be diagnosed through imaging exams. Often asymptomatic, they can be discovered incidentally. Due to their similarities, these tumors may be challenging to diagnose and differentiate between each other, thus the need for a complete and clear description of their main characteristics. The aim of this review is to give a picture of the benign bone tumors that clinicians can encounter more frequently in their everyday work.

Hydatid disease (Echinococcosis granulosis) diagnosis from skeletal osteolytic lesions in an early seventh-millennium BP forager community from preagricultural northern Vietnam

OBJECTIVES

Con Co Ngua is a complex, sedentary forager site from northern Vietnam dating to the early seventh millennium BP. Prior research identified a calcified Echinococcus granulosis cyst, which causes hydatid disease. Osteolytic lesions consistent with hydatid disease were also present in this individual and others. Hydatid disease is observed in high frequencies in pastoralists, and its presence in a hunter-gatherer community raises questions regarding human-animal interaction prior to farming. The objective of this article is to identify and describe the epidemiology of hydatid disease in the human skeletal assemblage at Con Co Ngua.

MATERIALS AND METHODS

One hundred and fifty-five individuals were macroscopically assessed for lesions. Of these, eight individuals were radiographed. Hydatid disease was diagnosed using a new threshold criteria protocol derived from clinical literature, which prioritizes lesions specific to the parasite.

RESULTS

Twenty-two individuals (14.2%) presented with osteolytic lesions consistent with hydatid disease, affecting the distal humerus, proximal femur and forearm, and pelvis. Seven individuals radiographed (4.5%) had multilocular cystic lesions strongly diagnostic for hydatid disease. All probable cases had lesions of the distal humerus. The remaining lesions were macroscopically identical to those radiographed and were considered possible cases.

DISCUSSION

While hydatid disease has previously been found in pre-agricultural communities, the high prevalence at Con Co Ngua is non-incidental. We propose that the presence of wild canids and management of wild buffalo and deer increased the risk of disease transmission. These findings further reveal subsistence complexity among hunter-gatherers living millennia prior to the adoption of farming in Southeast Asia.

Neoplastic Elbow Diseases and Mimickers

Tumors around the elbow are infrequent, and delayed diagnosis is a common theme because of the low incidence and lack of familiarity. However, just like any other site, the radiologic work-up of musculoskeletal tumors around the elbow remains the same, with plain films the first investigation in a patient with a suspected bone tumor and ultrasound the first modality to evaluate a soft tissue lump. The management of both bone and soft tissue tumors around the elbow is unique because of a large number of important structures in an anatomically confined space and little normal tissue to spare without severely compromising the joint's function. Many benign nonneoplastic entities can mimic bone and soft tissue tumors on imaging. It is important to keep the characteristic imaging appearance in mind while formulating a differential diagnosis to avoid an unnecessary additional work-up. This article reviews the most common benign and malignant bone and soft tissue tumors around the elbow, mimickers, imaging features, and current therapeutic concepts.

Case Report: Reconstruction After Anterior Pubic Hemipelvectomy

We report on a case of a large atypical cartilaginous tumor of the pelvis and its novel surgical resection with an anterior hemipelvectomy and reconstruction with an iliac crest graft. Surgical intervention is the mainstay treatment of pelvic chondrosarcomas. However, there have been reports of concern regarding preventing pelvic visceral herniation and adequately reconstructing the pelvis. This report is unique within the literature and has yielded good functional outcomes whilst achieving satisfactory surgical margins and minimizing morbidity.

Radiomics Nomograms Based on Non-enhanced MRI and Clinical Risk Factors for the Differentiation of Chondrosarcoma from Enchondroma

BACKGROUND

Differentiating chondrosarcoma from enchondroma using conventional MRI remains challenging. An effective method for accurate preoperative diagnosis could affect the management and prognosis of patients.

PURPOSE

To validate and evaluate radiomics nomograms based on non-enhanced MRI and clinical risk factors for the differentiation of chondrosarcoma from enchondroma.

STUDY TYPE

Retrospective.

POPULATION

A total of 103 patients with pathologically confirmed chondrosarcoma (n = 53) and enchondroma (n = 50) were randomly divided into training (n = 68) and validation (n = 35) groups.

FIELD STRENGTH/SEQUENCE

Axial non-contrast-enhanced T1-weighted images (T1WI) and fat-suppressed T2-weighted images (T2WI-FS) were acquired at 3.0 T.

ASSESSMENT

Clinical risk factors (sex, age, and tumor location) and diagnosis assessment based on morphologic MRI by three radiologists were recorded. Three radiomics signatures were established based on the T1WI, T2WI-FS, and T1WI + T2WI-FS sequences. Three clinical radiomics nomograms were developed based on the clinical risk factors and three radiomics signatures.

STATISTICAL TESTS

The area under the receiver operating characteristic curve (AUC) was used to evaluate the performance of radiomics signatures and clinical radiomics nomograms.

RESULTS

Tumor location was an important clinical risk factor (P < 0.05). The radiomics signature based on T1WI and T1WI + T2WI-FS features performed better than that based on T2WI-FS in the validation group (AUC in the validation group: 0.961, 0.938, and 0.833, respectively; P < 0.05). In the validation group, the three clinical radiomics nomograms (T1WI, T2WI-FS, and T1WI + T2WI-FS) achieved AUCs of 0.938, 0.935, and 0.954, respectively. In all patients, the clinical radiomics nomogram based on T2WI-FS (AUC = 0.967) performed better than that based on T2WI-FS (AUC = 0.901, P < 0.05).

DATA CONCLUSION

The proposed clinical radiomics nomogram showed promising performance in differentiating chondrosarcoma from enchondroma.

LEVEL OF EVIDENCE

4 TECHNICAL EFFICACY: Stage 2.

Team Approach: Evaluation and Management of Low-Grade Cartilaginous Lesions

» Assessment of chondral lesions begins with a clinical evaluation and radiographs. » Longitudinal follow-up with serial radiographs is appropriate in cases without evidence of aggressive radiographic features. » Concerning radiographic features include periosteal reaction, soft-tissue extension, cortical destruction, endosteal scalloping of greater than two-thirds of the native cortex, larger lesion size (≥5 cm), and location in the axial skeleton. » Biomarkers such as IMP3, SOX4, microRNA, and periostin may be used as an adjunct in histologic assessment to help differentiate benign enchondroma from a low-grade chondrosarcoma. » Advanced-imaging studies, such as computed tomography (CT), bone scans, magnetic resonance imaging (MRI), dynamic contrast-enhanced MRI, and fluorodeoxyglucose positron emission tomography (FDG-PET), may be considered for borderline cases. » Aggressive or concerning radiographic features should prompt evaluation with advanced imaging or referral to an orthopaedic oncologist.

Proximal Femur Chondrosarcoma Misdiagnosed as Hip Arthritis: A Case Report

CASE

A 60-year-old man presented with left hip pain, and a radiograph showed reduced joint space. During the surgical procedure for a total hip replacement, a proximal femur mass was identified and biopsy was subsequently interpreted as grade 2 chondrosarcoma. A wide resection was needed, but he developed local recurrence after 2 years and was treated with an external hemipelvectomy.

CONCLUSIONS

Chondrosarcoma does not always present with a classical clinical picture or imaging, and it can be misdiagnosed. Practitioners should be highly suspicious of malignant disease as a cause for hip pain even if there is no direct indication of a neoplasm such as chondrosarcoma.

Bone Scans Have Little Utility in the Evaluation of Well-Differentiated Cartilaginous Lesions of the Humerus

In the humerus, pain is a poor guide for differentiating between benign enchondromas and malignant well-differentiated chondrosarcomas. Radionuclide bone scans often are used, and chondrosarcomas reliably show increased uptake. However, it remains to be seen whether enchondromas consistently have negative findings on bone scans, which would provide reliable differentiation from malignant lesions. Imaging and medical records were reviewed for patients who underwent radionuclide bone scans for enchondroma of the humerus at one academic medical center over a period of 7 years. Bivariate logistic regression was used to determine the association of bone scan results with the finding of endosteal scalloping on radiographs and magnetic resonance imaging (MRI) scans. During initial evaluation, 25 patients who had enchondroma of the humerus underwent radionuclide bone scans. No patients showed progression of lesions during an average follow-up of 69 weeks. On bone scan, 18 (72%) had significantly positive findings, 5 (20%) had mildly positive findings, and 2 (8%) had negative findings. Of the 22 patients who underwent MRI scans, 4 showed endosteal scalloping and none showed aggressive features. No statistically significant association was seen between significantly positive (P=.299) or mildly positive findings on bone scans (P=.810) and the finding of endosteal scalloping on radiographs or MRI scans. Enchondromas rarely showed negative findings on bone scans, and bone scan findings did not correlate with the findings on radiographs or MRI scans. The diagnosis of enchondroma can be made based on clinical and radiographic findings, and the added utility of bone scans does not justify their regular use. [Orthopedics. 2020;43(6):e498-e502.].

Vascular tumors

Vascular tumors are a rare subset of vascular anomalies. These are classified based on their malignant potential or local destruction potential. Classification has been historically difficult and treatment recommendations are based on case series. The purpose of this chapter is to review the presentation, pathologic and imaging characteristics. Treatment recommendations are summarized based on the current literature. Congenital and infantile hemangiomas are covered separately in a separate chapter in this issue.

Total Knee Arthroplasty and Atypical Cartilaginous Tumor/Enchondroma of the Distal Femur

Enchondroma is a common benign chondrogenic tumor, which typically occurs in the short bones of hands and feet. However, when affecting the long bones, it is difficult to rule out the low-grade chondrosarcoma, called atypical cartilaginous tumor (ACT), because of the highly similar clinical and radiologic features. This study reports 2 patients with advanced knee osteoarthritis, scheduled for total knee arthroplasty, who had a distal femoral lesion on imaging suggestive of ACT/enchondroma. We believe that the treatment of these patients could be a challenge for arthroplasty surgeons. This is because it might be difficult to decide whether a periarticular chondral tumor of an osteoarthritic knee is malignant and changes the plan. In this report, we described our approach to address both knee osteoarthritis and ACT/enchondroma of the distal femur. To the best of our knowledge, this issue has not yet been discussed in the literature.

A case of enchondroma from Carolingian necropolis of St. Pere De Terrassa (Spain): An insight into the archaeological record

Enchondromas occur with an estimated modern incidence rate of 27.7% of benign bone tumors (Hauben and Hogendoorn, 2010), but few are represented in the paleopathological record. The medieval site of St. Pere in Spain has produced a convincing case. The diagnosis was confirmed by X-Ray, CT-scan and μ-CT scan. Therefore UF 755 from St. Pere - a male of more than 60 years old - can be confirmed as a femoral case of enchondroma, supported by evidence, in the paleopathological record.

Radiologic follow-up of untreated enchondroma and atypical cartilaginous tumors in the long bones

Background and Objectives

Both enchondroma and atypical cartilaginous tumors (ACT) are not considered malignant, so inactive and asymptomatic tumors might not need surgery. To the best of our knowledge, this is the first study that has been done to evaluate the natural course of conservative‐treated enchondroma and ACT in the long bones.

Methods

For this retrospective study, we analyzed the results of patients in whom we refrained from surgery and only regularly performed radiological follow‐up of the tumor. Minimal follow‐up after initial diagnosis was 24 months.

Results

Forty‐nine patients were included in this study. Eight out of forty‐nine cases received surgical treatment during follow‐up of the tumor. The reasons for this surgery were radiologic growth of the tumor in two cases, pain in one case, patient request in three cases, another indication for surgery in the same limb in two cases.

Conclusion

In this small series of conservatively treated enchondroma and ACT, only 6% of the patients had a medical indication for surgery. This study shows that indication for surgery should be discussed more thoroughly. Based on our results, we would recommend annual radiologic follow‐up for asymptomatic enchondroma or ACT in the long bones, irrespective of tumor size. J. Surg. Oncol. 2016;114:987–991. © 2016 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals, Inc.

Chondrosarcoma of the para-acetabulum: correlation of imaging features with histopathological grade

OBJECTIVE

To evaluate the computed tomography (CT) and magnetic resonance (MR) imaging features of para-acetabular chondrosarcoma (CS) and assess the difference between low-grade CS (LGCS) and high-grade CS (HGCS).

MATERIALS AND METHODS

Thirty-one patients with histopathologically confirmed central para-acetabular CSs (6 LGCS and 25 HGCS) were retrospectively reviewed. Image features were evaluated for the following: cortical destruction, tumor border and pattern, calcification mode, soft-tissue mass, density/signal intensity, peritumoral edema, acetabular (cartilage) destruction, diffuse signal changes in acetabulum, mass inside hip joint, femoral head involvement, enhancement manifestations and the maximum length of the tumor. These image features between LGCS and HGCS were also assessed.

RESULTS

The most common CT and/or MR findings included cortical destruction, punctate, ring-and-arc and linear calcification, soft-tissue mass, lobulated border, high signal intensity with low signal septa on T2-weighted image, peritumoral edema, hip joint infiltration, peripheral and septal enhancement on post-enhanced MR image. Statistical analysis showed that the image features, such as cortical destruction, soft-tissue mass, hip joint infiltration and tumor size were significantly different between LGCS and HGCS (p < 0.05).

CONCLUSION

The characteristic radiological features of para-acetabular CSs are osteolytic lesions with cortical destruction, soft-tissue mass, lobulated border, calcification, and high signal intensity with low signal septa on T2-weighted MR image, peripheral and septal enhancement on post-enhanced MR image. Cortical destruction, soft-tissue mass, hip joint infiltration and tumor size can differentiate HGCS from LGCS.

Delayed diagnosis of clear cell chondrosarcoma after total hip replacement. A case report of a rare entity encountered in common surgery

We report the case of a young female patient who received a total hip replacement due to pain in her left hip joint, misdiagnosed as degenerative arthritis. A clear cell chondrosarcoma (CCCS) in the femoral head had initially not been detected. Seven years later, a periprosthetic recurrence of CCCS close to the former femoral osteotomy occurred. Although a sample of the periprosthetic tumour had been taken for histologic analysis, the recurrence of CCCS remained misdiagnosed for almost 2 years until this rare histopathologic morphology was examined in a specialised multidisciplinary tumour centre. Finally, revision surgery with wide tumour resection margins had to be performed requiring the removal of the total hip replacement and its reconstruction using a modular megaimplant (proximal femoral replacement). Relevant facts of the CCCS as a rare entity regarding histology, treatment and differential diagnoses are discussed.

Imaging Diagnosis of Solitary Tumors of the Phalanges and Metacarpals of the Hand

OBJECTIVE

Tumors and tumorlike lesions of the tubular bones of the hand, often incidentally discovered lesions, present a unique but challenging differential diagnosis.

CONCLUSION

Imaging, including both radiography and cross-sectional imaging, can allow the radiologist to generate a clinically useful differential diagnosis based on the distinguishing features of these entities. Recognition of these lesions is important because clinical management and treatment by orthopedic oncologists vary depending on the diagnosis.

Prevalence of cartilaginous tumours as an incidental finding on MRI of the knee

Objectives

The purpose was to determine prevalence of enchondromas and atypical cartilaginous tumour/chondrosarcoma grade 1 (ACT/CS1) of the knee on MRI in a large cohort study, namely the Netherlands Epidemiology of Obesity (NEO) study.

Methods

Participants aged 45 to 65 years were prospectively included, oversampling overweight and obese persons. Within a subgroup of participants, MRI of the right knee was performed and screened for incidental cartilaginous tumours, as defined by their characteristic location and appearance.

Results

Forty-nine cartilaginous tumours were observed in 44 out of 1285 participants (estimated population prevalence 2.8 %, 95 % CI 2.0–4.0 %). Mean largest tumour diameter was 12 mm (range 2–31 mm). Eight participants with a tumour larger than 20 mm or a tumour with aggressive features were referred to rule out low-grade chondrosarcoma. One was lost to follow-up, three had histologically proven ACT/CS1 and four had dynamic contrast MRI findings consistent with benign enchondroma.

Conclusions

Incidental cartilaginous tumours were relatively common on knee MRI and may be regarded as a normal concurrent finding. However, more tumours than expected were ACT/CS1. Because further examination was performed only when suspicion of chondrosarcoma was high, the actual prevalence might be even higher.

Key Points

• Incidental cartilaginous tumours are relatively common on knee MRI.

• Most incidental cartilaginous tumours are small and lack suspicious features.

• Small cartilaginous tumours without suspicious findings may be a normal concurrent finding.

• Large tumours and/or those with suspicious findings should be further investigated.

• Atypical cartilaginous tumour/chondrosarcoma grade 1 was found more often than expected.

The myriad of diseases that present with polyostotic bone lesions

Many diseases result in polyostotic bone lesions including benign entities, benign entities with malignant potential, intermediate entities, and malignant entities. Imaging plays a key role in identifying complications of these disorders, most importantly malignant transformation of a benign lesion. The most common polyostotic bone lesions are reviewed and examples of malignant transformation are highlighted.

Top five lesions that do not need referral to orthopedic oncology

Patients with potential bone and soft tissue tumors can be challenging for orthopedic surgeons. Lesions that appear benign can still create anxiety for the clinician and patient. However, attention to a few key imaging and clinical findings is enough to correctly diagnose five of the most common bone and soft tissue lesions: lipoma, enchondroma, osteochondroma, nonossifying fibroma, and Paget disease. Accurate identification of these lesions should be within the scope of most orthopedic surgeons and, because most of these patients will not need surgical treatment, referral to orthopedic oncology will not typically be required.

Phenolization and coralline hydroxyapatite grafting following meticulous curettage for the treatment of enchondroma of the hand. A case series of 82 patients with 5-year follow-up

BACKGROUND

Enchondromas are benign cartilaginous tumours. The most common location is in the long bones of the hand. Treatment methods fall into a broad spectrum ranging from conservative, medical therapies, to a variety of surgical procedures, which may or may not employ the use of local adjuvant treatment or bone grafting. The purpose of this study was to report our experience and evaluate the long-term results of patients with enchondroma of the hand, treated in our department with meticulous curettage, phenolization and coralline hydroxyapatite grafting.

METHODS

We present 82 patients with hand enchondromas treated surgically in our department during the last 10 years. The patients were treated operatively with meticulous curettage of the bone lesion, with use of phenol 5 % as local adjuvant and coralline hydroxyapatite bone graft to fill in the remaining cavity.

RESULTS

At a minimum of 5-year follow-up, radiographs and clinical examination showed adequate bone formation at the site of enchondroma excavation and no evidence of recurrence, fracture, infection or other complication related to the procedure.

CONCLUSION

We concluded that the combination of meticulous curettage of the lesion, with the use of phenol as local adjuvant and coralline hydroxyapatite graft is a safe technique that prevents recurrence and allows adequate and uncomplicated local new bone formation.

Pelvic reconstruction after subtotal sacrectomy for sacral chondrosarcoma using cadaveric and vascularized fibula autograft: Technical note

A novel method of spinopelvic ring reconstruction after partial sacrectomy for a chondrosarcoma is described. Chondrosarcoma is one of the most common primary malignant bone tumors, and en bloc resection is the mainstay of treatment. Involvement of the pelvis as well as the sacrum and lumbar spine can result in a technically difficult challenge for en bloc resection and for achievement of appropriate load-bearing reconstruction. After en bloc resection in their patient, the authors achieved reconstruction with a rod and screw construct including vascularized fibula graft as the main strut from the lumbar spine to the pelvis. Additionally, a cadaveric allograft strut was used as an adjunct for the pelvic ring. This is similar to a modified Galveston technique with vascularized fibula in place of the Galveston rods. The vascularized fibula provided appropriate biomechanical support, allowing the patient to return to independent ambulation. There was no tumor recurrence; neurological status remained stable; and the allograft construct integrated well and even increased in size on CT scans and radiographs in the course of a follow-up longer than 7 years.

Syndromes associated with vascular tumors and malformations: a pictorial review

Use of the International Society for the Study of Vascular Anomalies (ISSVA) classification system has been strongly recommended in recent years because of the need for separate therapeutic measures for patients with vascular tumors and malformations. In the ISSVA classification system, vascular tumors, which are neoplastic, are distinguished from vascular malformations, which are caused by vascular structural anomalies and are not neoplastic, on the basis of the presence or absence of neoplastic proliferation of vascular endothelial cells. It is important that radiologists be familiar with the development, diagnosis, and treatment of vascular tumors and malformations, especially the imaging features of low- and high-flow vascular malformations. Some vascular tumors and malformations develop in isolation, whereas others develop within the phenotype of a syndrome. Syndromes that are associated with vascular tumors include PHACE syndrome. Syndromes that are associated with vascular malformations include Sturge-Weber, Klippel-Trénaunay, Proteus, blue rubber bleb nevus, Maffucci, and Gorham-Stout syndromes, all of which demonstrate low flow, and Rendu-Osler-Weber, Cobb, Wyburn-Mason, and Parkes Weber syndromes, all of which demonstrate high flow. Because imaging findings may help identify such syndromes as systemic, it is important that radiologists familiarize themselves with these conditions.

The role of MRI in image-guided needle biopsy of focal bone and soft tissue neoplasms

Magnetic resonance imaging (MRI) plays a critical role in the management pathway of both soft tissue and bone neoplasms, from diagnosis through to post-treatment follow-up. There are a wide range of surgical, oncological, and combined treatment regimes but these rely on accurate histopathological diagnosis. This article reviews the role of MRI in the planning of image-guided needle biopsy for suspected soft tissue and bone tumors.

High-grade intracranial chondrosarcoma presenting with haemorrhage

Chondrosarcomas are rare sarcomas that produce malignant cartilage, infrequently arising as a primary intracranial tumour. We present a patient with intracranial chondrosarcoma with intratumoural haemorrhage arising in an unusual location and with unusual imaging findings. A 46-year-old man presented with headache, nausea, and vomiting over the previous 24 hours. Physical and neurological examinations were normal. Cranial CT scans and MRI revealed a large right pre-frontal (subdural) and interhemispheric heterogeneous density associated with a frontal, partially calcified mass and midline shift. An awake craniotomy was performed. With the intra-operative quick section favouring subdural hematoma, the lesion was subtotally resected. Follow-up imaging confirmed residual mass. Pathology examination revealed a high-grade malignant neoplasm with chondroid differentiation, diagnosed as conventional Grade III chondrosarcoma. The patient was referred to oncology for follow-up and radiation therapy. Intracranial chondrosarcoma was first reported in 1899, and since then continues to be an extremely rare malignancy of the brain. These tumours commonly present as extra-axial masses, originating from the skull base, and produce symptoms due to progressive enlargement and compression of local structures. Unusual presentations of these tumours, such as vascularity, intratumoural haemorrhage, and intra-axial location, may complicate pre-surgical decision making by altering the provisional diagnosis prior to intervention. This patient emphasises the importance of careful analysis and incorporation of imaging findings into surgical decision making. Specific imaging characteristics that, in such unusual situations, are suggestive of chondrosarcoma should motivate an aggressive surgical approach to optimise adjuvant interventions.

The imaging of cartilaginous bone tumours. II. Chondrosarcoma

Chondrosarcoma is the third most common primary malignant bone tumour. There are various histological subtypes of chondrosarcomas, of which conventional intramedullary chondrosarcoma is by far the most common. Rarer sub-types include clear cell chondrosarcoma, myxoid chondrosarcoma, mesenchymal chondrosarcoma and dedifferentiated chondrosarcoma. Chondrosarcoma is also classified into central, peripheral and periosteal, dependent upon the lesion site, and into primary chondrosarcoma if the lesion arises de novo and secondary chondrosarcoma if the tumour arises in a pre-existing lesion. The various subtypes of chondrosarcoma have characteristic imaging features that may aid diagnosis and may guide biopsy, therefore potentially preventing misdiagnosis. The aim of this article is to provide an overview of the pertinent clinical and imaging findings of the different forms of chondrosarcoma.

MR differentiation of low-grade chondrosarcoma from enchondroma

PURPOSE

To evaluate magnetic resonance (MR) imaging for the discrimination between low-grade chondrosarcoma and enchondroma.

MATERIALS AND METHODS

MR images of 34 patients who were confirmed with low-grade chondrosarcoma or enchondroma were retrospectively reviewed. After review of medical records, MR findings in 18 patients with low-grade chondrosarcoma and 16 patients with enchondroma were compared. MR images were retrospectively reviewed for the lesion location (central or eccentric; epiphysis, metaphysic, or diaphysis), margin, contour, mineralized matrix, endosteal scalloping, cortical expansion, cortical destruction, soft tissue mass formation, and periosteal reaction. Signal intensity, the patterns of contrast enhancement (unilocular or multilobular), soft tissue mass, and adjacent abnormal bone marrow and soft tissue signal were also reviewed. Statistical analysis was performed with chi-square test.

RESULTS

The patients with low-grade chondrosarcoma had a significantly higher incidence of MR findings (P<.05): predominantly intermediate signal on T1-weighted images [72% (13/18) in low-grade chondrosarcoma vs. 25% (4/16) in enchondroma], multilocular appearance on contrast-enhanced T1-weighted images [83% (15/18) vs. 44% (7/16)], cortical destruction [33% (6/18) vs. 0% (0/16)], a soft tissue mass [28% (5/18) vs. 0% (0/16)], adjacent bone marrow and soft tissue abnormal signal [22% (4/18) vs. 0% (0/16)], and an involvement of the epiphysis or flat bone [56% (10/18) vs. 19% (3/16)].

CONCLUSION

MR imaging shows helpful features for differentiating low-grade chondrosarcoma from enchondroma.

The imaging of cartilaginous bone tumours. I. Benign lesions

Benign cartilage tumours of bone are the most common benign primary bone tumours and include osteochondroma, (en)chondroma, periosteal chondroma, chondroblastoma and chondromyxoid fibroma. These neoplasms often demonstrate typical imaging features, which in conjunction with lesion location and clinical history, often allow an accurate diagnosis. The aim of this article is to review the clinical and imaging features of benign cartilage neoplasms of bone, as well as the complications of these lesions.

Is bone scintigraphy necessary in the initial surgical staging of chondrosarcoma of bone?

OBJECTIVE

To assess the value of whole-body bone scintigraphy in the initial surgical staging of chondrosarcoma of bone.

METHODS

A retrospective review was conducted of the bone scintigraphy reports of a large series of patients with peripheral or central chondrosarcoma of bone treated in a specialist orthopaedic oncology unit over a 13-year period. Abnormal findings were correlated against other imaging, histological grade and the impact on surgical staging.

RESULTS

A total of 195 chondrosarcomas were identified in 188 patients. In 120 (63.8%) patients the reports of bone scintigraphy noted increased activity at the site of one or more chondrosarcomas. In one patient the tumour was outside the field-of-view of the scan, and in the remaining 67 (35.6%) cases, there was increased activity at the site of the chondrosarcoma and further abnormal activity in other areas of the skeleton. Causes of these additional areas of activity included degenerative joint disease, Paget's disease and in one case a previously undiagnosed melanoma metastasis. No cases of skeletal metastases from the chondrosarcoma were found in this series. Multifocal chondrosarcomas were identified in three cases. In two it was considered that all the tumours would have been adequately revealed on the initial MR imaging staging studies. In only the third multifocal case was an unsuspected, further presumed low-grade, central chondrosarcoma identified in the opposite asymptomatic femur. Although this case revealed an unexpected finding the impact on surgical staging was limited as it was decided to employ a watch-and-wait policy for this tumour.

CONCLUSION

There is little role for the routine use of whole-body bone scintigraphy in the initial surgical staging in patients with chondrosarcoma of bone irrespective of the histological grade.

Well-Differentiated Central Cartilage Tumors of Bone: An Overview

Well-differentiated hyaline cartilage tumors are among the most common tumors encountered in the skeleton; their radiographic and pathologic classification and clinical management can be challenging. Pathologists find cartilage tumors difficult because their precise classification is as dependent on the clinical and radiographic findings as the histologic features; the distinction between benign and malignant cartilage neoplasms demands good communication and teamwork between pathologists, orthopedic surgeons, and radiologists. This review focuses on the necessary clinical, radiographic, and pathologic features that allow distinction between enchondroma and low-grade central chondrosarcoma and interpretation of lesions encountered in the enchondromatosis syndromes.

Imaging of sarcomas of pelvic bones

Sarcomas are the most common nonhematologic primary malignancies of bones in the pelvis. Chondrosarcoma, osteosarcoma, and Ewing's sarcoma are the most common sarcomas to originate from the pelvic bones. Various imaging modalities such as magnetic resonance imaging and computed tomography play an important role in the detection, characterization, and staging of these lesions. Biopsy, usually performed with imaging guidance, is essential for the histologic diagnosis of these tumors and for planning therapeutic options. Despite considerable advances in treatment options, sarcomas in the pelvic bones generally are associated with poorer outcomes than sarcomas in the appendicular skeleton because of the larger size of the lesions at the time of discovery and the difficulty of obtaining a wide surgical resection margin. In this review, we discuss the various types of pelvic bone sarcomas and the role of imaging in patients with these lesions.

Imaging of primary malignant bone tumors (nonhematological)

Primary malignant bone tumors are uncommon and are diagnosed typically based on radiographic and microscopic findings combined with clinical and demographic features. CT and MR imaging scans are useful in further staging the tumors by determining intraosseous and extraosseous spread.